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OK. Uh Yeah, thank you everyone for joining. Uh So today, uh we have our fourth installment uh which I'll be giving myself today uh in collaboration between uh the Cambridge University G Society s and uh the Cambridge er educ Medical Education Society. Uh So today we'll be going through uh how to interpret uh a cardiotocograph uh and how to sort of uh unpick er obstetric and gynecological ultrasound scans and work out what pathology is there right in front of you, uh which are really useful skills. Uh not only for your maternal health block and your, your S AQ exams coming up uh but also for F one jobs and beyond. Uh So it's really common uh that you will have a placement on the labor ward as an F one. it's compulsory to do gyne placements um as part of GP training. Uh So this is a very important skill to have and of course, ultrasound is a very good test because it's noninvasive um and it doesn't involve any radiation. So it's a very good skill to be able to interpret them well. Um and just a disclaimer, I am certified by the Royal College of Obstetricians and Gynecologists and the Royal College of Midwives to interpret uh, fetal CTG S. Er, so, you know, you'll be in good hands uh, with how to interpret these. Um, yeah, and as, as long as you stay until the end, uh, we'll have some free resources for um, ES AQ exams, er, coming up at the end, uh, once you fill out the feedback form, er, we'll give you some pass questions to work through some obs gynae cases and a little bit of extra um information with work answers uh that we won't have time to go through today. Um Also this, the slides and the recording will be uploaded at the end uh to the, the Google Drive. Uh If you have any questions about how to get that, uh please uh ask me at the end and uh I can make sure you have access uh without further ado let's get on to the CTG part of the talk. Um So, firstly, where does the word CTG come from? What are we actually looking at when we talk about a CTG? Well, like most things in medicine, it comes from uh Greek. Uh So we've got cardio from cardia, meaning the heart. Uh We've also got Tokos, which means childbirth and Grap Os, which means writing. So, put that all together and you've got um we're looking at the, the fetal heart during childbirth and we're writing it down on a graph. So we get this sort of picture at the end there. Um OK. So that's what the actual reading looks like. What is this gonna look like when you go on to the lab ward? Uh So this is your sort of bog standard machine. It's not quite as advanced as the ones you get in Adam Brooks. Um But in the, the peripheral uh DG HS, this is the sort of thing you'll be working with. Uh So on the left hand side, you have the fetal heart rate, you can tell it's the fetal heart rate because the, the normal range is uh from 110 to 160. Uh whereas that obviously below 100. So it's quite a marked difference here. We have the, the strength of the uterine contractions. It's a bit of an arbitrary number, but it's on a scale of 0 to 100. Uh So you can get sort of feel the, whether the woman is in diastole, uterine, diastole or uterine systole at that point. Um of uh labor here, you have the maternal heart rate, which we just from a normal sax probe on her finger. Um And at the bottom, of course, we have a paper read out, um which has a cardio on it which we'll be interpreting in a moment. Um In Adam Brookes, they do also have uh a screen in the nurse's station, uh which is hooked up to all of the, the cardiographs in the unit so that the nurses can see straight away if there's an abnormality developing, um, without having to go to the actual bedside, um, which is normally only done, uh, every 15 minutes. If there's, there's nothing to worry about so far. Um, ok, so that's the actual machine. On the other side, you have the two probes attached to the patient. So we have this one at the top, which is the transducer for uterine contractions. And we've got this one on the side, uh which is the transducer picking up the fetal heart rate. Um Yeah. So the these uh if we, if we look at it on a cross section, we can see er why they're that way around. Uh So normally, uh the normal position to, to, to, to undergo childbirth is in the ossip, anterior position where baby's head is coming before the legs and their ossip put at the back of the head is anterior in, so anterior in the birth canal. Uh So that's why the, the transducer is around this position. And it may have to be shifted around by the midwife to, to obtain a good reading. Uh sometimes in obese patients, we may struggle to get a reading. Um So there's a few things we can do to try and fix that. Firstly, we can ask her to reposition, which is a good way to stimulate the baby to, to change position and expose their heart towards the front uh of, of the stomach. Um And we can also uh reposition the electrodes, as I said, but if all else fails, then we can use internal monitoring. Um If we're already worried about uh fetal hypoxia. Um So we do that with an intrauterine catheter to detect the strength of contractions. And we make a small incision in the baby's head um to insert a scalp electrode to manually measure the, the fetal heart rate there. Um Yeah. OK. So, what are we actually doing the CTG for? Um So the main thing we're looking for. Um Yeah, so as I say, we've got the intrauterine catheter there and that's the scalpel xray there. Um So, yeah, the main thing we're looking for with the CTG is uh if they fetal hypoxia. Uh The reason for this is fetal hypoxia can lead to fetal acidosis and acidosis can lead to hypoxic ischemic encephalopathy. So, brain damage from a lack of blood supply during labor or is sometimes abbreviated to hie. Um And this is impossible because it can be uh it's the leading cause of cerebral palsy. Um So it can cause quite significant lifetime morbidity uh if we don't catch it and prevent it early. Um Yeah. So let's talk about how we can actually read the CTG and pick up on those changes that indicate hypoxia in the fetus. So you'll always have your fetal heart rate on the top here. Um And you'll have the strength of the mother's uterine contractions on the bottom here. Um So there is a, a really good algorithm that a lot of you will probably be aware of for interpreting uh CTG S er And that is Doctor C Bragard. OK. Uh So we'll go through what each one of those mean now and how to tell if they're normal pathological uh or worrying. Uh So, Doctor Steve Bravado stands for firstly define the risk. Um It does this woman have any risk factors for fetal hypoxia, uh the contractions, the baseline rate, the variability in the trace accelerations and decelerations. And then at overall interpretation and this is what you should be working through. Uh when uh the consultant or the F one on the ward asks you to interpret the CTG. Uh You should make sure you go through all of these and don't miss any of them at all. Um OK. So to start off with um define risk. So when we talk about risk with the CTG, we're really looking at risk of the fetus developing fetal hypoxia. Um So there's quite a few risk factors to be aware of and these are the kinds of things that they'll ask you about on exams. Uh So worth knowing. Uh firstly, multiple pregnancy comes with a lot of associated risks. So when you have, when, when you have more than one fetus in the uterus, um it puts you at higher risk of preeclampsia. So where you have uh high BP with end organ damage after 20 weeks, gestation, uh being in the breech position. So where um as opposed to being a anterior and a cephalic presentation, you have uh presentation with the, the feet or the cad end of the baby first, um intrauterine growth restriction, which is shown in this baby on the left hand side next to a normal baby. Um That's another risk factor because they have a lower reserve um of oxygen stored in their body. Uh So they can't go as long uh during uh uterine contractions, um cord compression, um or cord prolapse out of the uterus that sometimes the cord can be pushed out before babies come out and that puts it at risk of being contracted to having the blood supply cut off. Um And also multiple pregnancies are at higher risk of being born prematurely. So, before 37 weeks and zero days, that's considered premature. Um So all of these risk factors are not only associated with hypoxia but also with multiple pregnancy. Uh In addition, there are a couple of other risk factors. So, autoimmune disease. Uh if the mother has celiac or uh lupus, for example, um alloimmunization uh which uh for those of you who aren't, haven't come to your maternal health block yet. Um The if uh a mother has a rhesus negative blood type, so she's a negative O negative A B negative B negative. Um Then she will have uh she can develop antibodies against uh the rhesus antigen if the her first pregnancy is rhesus positive. So, if they had been inherited a positive er genotype from the father, um and then in subsequent pregnancies, those antibodies can cross the placenta and induce hemolysis of the the new fetus um by attacking the red blood cells. Uh And obviously, if you have hemolysis, you're going to be at risk of developing hypoxia. You can see you've got reduced carrying capacity. Uh In addition, uh maternal infection is a strong risk factor. So, um when the, when the mother has uh a high temperature during uh labor, uh it reduces the fetuses, uh response to changes uh in the oxy ox oxygenation levels at the chemo receptors. Uh So it reduces the, the gain in the, the sympathetic system. Um So that can put them at increased risk as well. Uh placental abruption where you have bleeding behind the placenta, um which limits the sort of contact area for gas exchange, uh having an induced birth which can uh make the uterus contract too long or too frequently. Uh And finally having it fresh in the on examination uh of, of uh the baby's progress. Uh So only if the meconium, which is the the first bowel movement of the baby, uh if that's new. So that infers that it's passed during labor as opposed to as a result of the baby being Postdates and having a fully developed uh gastrointestinal system. Um ok. So those are risk factors. So the first thing we want to think about, we have to know the woman's history, think if she has any of these risk factors, uh especially multiple pregnancy. Um and then we can get move on to the CPG to see uh if there are any concerning features uh manifesting in the, the, the heart race. So doctor C bravado next is contractions. Um So the contractions refers to what is the frequency of the contractions. Um So to do that, we need to know the, know the scale. Uh So again, we're looking at the bottom half the uterine contractions, er the best way to remember I think is we always have these Y axis exactly 10 minutes apart. Um So you can al if you can't remember how big the boxes are, it's always 10 minutes between the axis. Um If you can remember the, the boxes, the big ones, which are two of the little ones that is one minute across and that means each little box is 30 seconds. OK. So 10 minutes between them and the way we phrase it is how many contractions have they had in a 10 minute period. So again, the easiest way is just to look at te 10 minutes between the axes, how many contractions have they had? So, uh how many times has the uterine force increased? So, we've got one there, two there and three there. Um So you can see, yeah, that's a rate of three in 10. Um The normal is four or fewer. Uh if you have five in 10 or six in 10, anything five or more, uh that is termed uterine tachysystole, so fast contractions of the uterus. Um and that puts you at risk of developing uh uterine hyperstimulation, which is where tachysystole has resulted in fetal heart rate changes in the, the fetal trace. Um But if it's, if the contractions are fast and the fetal heart rate is still normal, the fetus is compensating. Well, it's just called uh tachysystole. Uh So yeah, that's another thing to look out for uh the, the actual magnitude of the contractions isn't as important unless it's sort of off the scale. Uh We're mainly looking at the frequency here. Uh This is also useful if you're trying to determine whether the woman is in true labor or not, we can use something called the, the 511 rule. Uh which means that true labor starts uh when we have uh at least five contractions within an hour each, lasting one minute each. Um Yeah, so once that started, then we're in true labor. Um OK. So moving on doctor C Bravado next is baseline rate. Uh So what do we mean by this? We mean the, the baseline heart rate of the fetus um ignoring any accelerations or any decelerations, which we'll come on to in a moment. Uh So the way you do this is you just look at a relatively constant bit of the trace and it's just in the middle of the variations here. Um So it's important to, to think about what we're, we're looking at here as well. So, uh a lot of people when they first see AC KG assume that it's like an E CG um looking at uh electrical changes. Uh But what it's actually doing is it's just plotting the, the, the fetal heart rate over time. Um So yeah, we can just take the midpoint of that line and that will tell us our baseline rate. Um So we can categorize this as normal, uh which we, we technically call reassuring uh non reassuring or abnormal. Uh So the normal rate for fetus is 100 and 10 to 100 and 60 BPM. So here we can see we're at 1 21 30 in the middle of that. So that would be a normal baseline rate. It would be reassuring if it's um 100 to 100 and nine or 100 and 61 to 100 and 80. And it's turned abnormal if it's less than 100 or more than 100 and 80. Um We'll come onto these in a moment we use uh We have to remember which non reassuring and abnormal findings we get uh when we come to define the uh overall interpretation of the CT gene. Um So, yeah, moving on. Uh we, oh, let's, let's just talk about why these might be linked to the hypoxia first. Um So when we, when we get hypoxia in the fetus, uh the first thing that's gonna happen is they'll increase their parasympathetic er, drive and that will reduce uh fetal movements by suppressing the somatic nervous system um to lower that oxygen demand. Uh But if that hypoxia persists, then we'll start getting end organ hypoxia and acidosis, which should stimulate the fetal sympathetics to try and secrete adrenaline and noradrenaline to try and perfuse those organs. Uh So that's why it can be abnormal if it's starting to go down. Um Because we're getting increased parasympathetics or if it's really high because we, we've got that end all of damage and we're, we're stimulating the sympathetics instead. Uh So that it's, it's important to think about what these actually mean, not just remembering the categories. Um Yeah, moving on doctor C bravado. Um So next, we've got the variability and the variability means how again, ignoring the accelerations or decelerations, how much does the, the baseline rate vary around that midpoint that we've defined? Um So we, the, the way I think of it is just draw across where the, the majority of the peaks are ignoring any sort of outliers like this one and across all the troughs here. Uh So the variation there, we've got going from 125 to 1 what are we at 150 there? Uh So this one would, so it's a one, so 130 to 150 there. So you've got a baseline uh variability of 20 BPM. So the top take away the bottom. Um a little bit more confusing to, to state if it's reassuring or not. Um That, that is reassuring. Um It's termed non reassuring if it's low. Uh So less than five variability. So it's the, all the, the lines are very close together for 30 to 50 minutes that becomes abnormal if it lasts for more than 50 minutes. Uh If it, if it varies massively, um more than 25 BPM, uh ignoring the acceleration of decelerations, then uh it only has to last for 15 minutes before that's non reassuring 25 minutes uh until that's abnormal. Um Yeah, so, ii remember this as uh sort of fif 30 to 50. If you half each, each of those, you get 15 to 25 just make it a little bit easier for myself. Um Yeah, let's let, let's let's again, think about why that might be happening in hypoxia. So the the variability is really telling us how sensitive the the fetal nervous system is to changes in the oxygenation levels. So how well your sympathetic and parasympathetic nervous system are responding to the change, the very slight changes in the the level of oxygen oxygenation in your sats. Uh So, again, once end organ hypoxia sets in, you're getting an increased sympathetic response. Um and this is gonna trigger a high gain of control in the fetal heart rate. So you get really high variability if you're getting those sympathetics. Uh but as hypoxia progresses, then your vasomotor center starts to take over. Uh and that induces low gain control of the fetal heart rate, um which really reduces the, the variation. Um So like, like we said before, it starts off, you get um you, you get sympathetic stimulation which begins by making it really high. Um And then once you have uh a progression of your hypoxia, the fetus really tries to conserve its energy um by limiting the, the autonomic responses. Um and it induces really low gain control, um limiting the variation in the trace. Um low variation can be normal um especially before 28 weeks. Um And if it lasts uh less than 40 minutes, it can be a, a sign that the fetus is uh which is a term we use for when it's resting uh in between its periods uh of somatic movement when its oxygen demand is a uh a lot lower. Um But importantly, during labor giving opiates, um giving benzodiazepines or magnesium sulfate, those can all cause a low variability as well. Um So, it's important to remember, we're not just looking at hypoxia causing these changes that are other changes to rule out first. Uh moving on um we also have a sinusoidal uh variability, which is you really, you see it straight away. Uh So here you can see it's sort of sinusoidal here, it's um not spikey like it was before, but it's more, more curved. Um This is an abnormal sign on its own. So if you see uh sinusoidal variability, uh that means you've got one abnormal sign and you need to intervene. Um So yeah, the sinus a variability indicates uh one or two things. It can either mean that there is maternal or fetal hemorrhage or it can mean that there's severe fetal anemia. So, again, both are the signs that there's uh a really high risk of hypoxia developing uh in the immediate future. Um So, if you have sinusoidal variability on its own, that should prompt delivery within the next 30 minutes. Um Otherwise there's a high risk of fetal demise. Um Yeah. OK. Moving on. Yeah. So next, uh obviously, bravado accelerations. Uh So, accelerations are defined as an increase from your baseline rate of more than 15 BPM. So our baseline rate was uh 140 here. We've got it increasing. Uh well past 155. Uh So that's an acceleration and that's lasting more than 15 seconds. Er which again is half of one of the small boxes. Um accelerations are a good sign if we have them. Um So it shows that the fetus they, they happen when the fetus uh starts moving around and the fetus isn't going to be moving around unless it has the, the oxygen supply to do that. So if you see them, it's a reassuring sign. Uh But if they're, they're absent, it's not necessarily pathological. It can just indicate again that the fetus is sleeping and is going through uh a time of ta. Um you can test uh and try and induce accelerations, uh which you can do when you're getting signed off for your vaginal examinations. Uh by pressing on the fetal head. Um We routinely do this uh to see how labor is progressing to see where the fetal head lies in relation to the spines here. Um And when you press on the fetal head, if the, the fetus has a good oxygen reserve, it should induce uh some movements. As you can imagine when you're poking the baby in the head, it's going to move around a little bit. Um So poking the head like this should stimulate some movements. And if you see an acceleration then on the CTG, that's another reassuring feature. So that's all good. Uh Moving on, we also have decelerations. Very simple. Uh It's the same thing again, but a decrease of 15 BPM from the baseline for at least 15 seconds. So here we can see decelerations. All of these are decelerations uh and they're categorized uh as either early, late or variable. OK. Uh So, uh let's start off with the I think we start with late decelerations. Yeah. Uh So these ones here are late decelerations. So that means they start when at the peak of the uterine contraction, um when we, when we're at peak uterine contraction and they don't recover back to the baseline until after the uterine contraction has completed. So if you see decelerations, uh you have to draw the line down to see where they start and stop here, we have another late deceleration, starting at the peak of uterine contraction and not recovering until afterwards. Uh So these on their own are not necessarily pathological, but they're, they're not a reassuring sign. Um If they're present in at least 50% of the contractions for a period of under 30 minutes, then that would be non reassuring. They would be abnormal if that started to go on for more than 30 minutes or if there's other risk factors of uh hypoxia in labor. So, like we mentioned before, all of those risk factors, uh especially fresh meconium uh or if there's evidence of uh hemorrhage as well. Um Yeah. OK. And the, the reason these are happening is uh the uterine contractions are compressing the spiral arterioles which are perfusing the placenta and preventing them from perfusing the, the fetus with fresh oxygenated blood in the uterine vein. Um The fact that they don't recover until after the contraction has stopped is telling you that there's uh a sort of watershed. Um And that the fetus has to regain its normal level of uh oxygenation. Um It's also very uh non reassuring uh if they don't return to the baseline afterwards. Uh Because then that suggests that the fetus isn't fully recovering from the hypoxia, the intimate hypoxia from the, the uterine contractions there. Um ok. So, yeah, moving on, we've done late contractions. Uh So next, we'll do early contractions. These are where the uterine contraction starts and then we get a deceleration. And then by the time the uterine contraction is finished, uh we return to the baseline. So we've got one here again. This one doesn't start until the uterine contraction starts and it recovers around the same time. Same again here. Uh So this is synchronous and it's because the, the u that, that means that the uterus is squeezing on the fetal barrow receptors um and causing a synchronous drop in uh the BP because contractions are interpreted as high BP, the fetus will reduce it's heart rate to try and compensate for that. So as soon as the contraction is over, it comes back up to baseline. Uh So it indicates that we're not having to recover from a hypoxia. Um And a prolonged hypoxia, we're actually just recovering from the increased pressure in the uterus instead. Um OK. So those are early decelerations and then finally variable. So, variable decelerations are where they don't line up into either of those first two categories. So they they, they neither start and stop at the same time as the uterine contractions, nor do they start at the peak of the, the uterine contractions. Um So they're non reassuring if at least half of the decelerations have any of these features um for less than 30 minutes and the abnormal if that continues past 30 minutes. Um Or if there are any risk factors, like we said before, if there's uh fresh blood or fresh meconin, uh which are again, risk factors for hypoxia. Um So any of these characteristics, like the consideration lasting more than 60 seconds, like we said before, don't return to the baseline rate afterwards. If there's reduced variability within the contraction, if it's, if it's long enough, uh then you can, you might see the line is relatively flat rather than it should still have the, the variability within the, the, the deceleration if they bi phase it. So you can really see on this one that it comes down, the rate increases again, it comes down and increases again all within the same deceleration. So that is a concerning characteristic right there and also having absent shouldering. Um So I'll, I'll show you what I mean by shouldering now. Um So these are shoulders on your, your CPG here. Um So it's where you have an increase in the, the heart rate before and after the deceleration. Um So if we think about what's happening there, why is this actually happening? Uh if you think back uh to your um human reproduction lectures, you remember that we have a single uterine vein, supplying oxygenated blood to the fetus and they return um the, the deoxygenated blood to the placenta by two arteries, er, the umbilical arteries uh left and right. Um So when we get a contraction, uh we expect to see shouldering. Uh That's another reassuring feature. Um So when we contract the, the uterine vein is uh a, a lower pressure than the arteries. It's at about 20 millimeters of mer mercury, the arteries are about 50 millimeters of mercury. So even though it's supplying oxidated blood, it, when the uterus contracts, the blood supply in the vein is cut off first. Um So as that happens, the, the u the, the fetus receives uh less oxygenated blood. There, the oxygen is cut off, they start to become hypoxic. Um Then we get uh further contractions tightening until it cuts off the supply in the er umbe of arteries. Um So that's reducing the, the venous return back to the placenta um and increasing the afterload uh on the fetal heart. Uh So that's why we get uh the sort of increase at the start where we've got hypoxia, they, they, they increase their, their sympathetics a little bit, then we get uh the, the cutting off of the deoxygenated blood returning. So then it falls and we get a proper deceleration and then the opposite occurs when the uterine contraction is uh easing off towards the end, an absent uh absence of er shouldering on the dese operations indicates that there's an inability of the, the fetal autonomic to compensate for the initial hy hypertension. And then the later hypercapnia, er which is a, a sign that there's a poor oxygen reserve within the fetus that they can't respond as well um and compensate for transient hypoxia. Um Let's see. And then another feature uh where I say the var variable decelerations are longer than 60 seconds. Uh This is what they look like here. Uh This one you can see is really prolonged, lasting at least 12 minutes. Um And it doesn't return back to the baseline here. So that on its own is uh an abnormal feature um if it lasts more than three minutes, uh That's the final thing that we have to look out for um on the CTG. If the deceleration lasts longer than three minutes at all, then that on its own is an abnormal feature and they need to be uh delivered within 30 minutes. Um OK. So we've done doctor see Brevard and now we just have the overall interpretation of our CTG. Uh So like we have reassuring, non, reassuring abnormal features, uh We classify the overall CTG as reassuring, suspicious of fetal hypoxia or pathological. Um So there's uh a, a short algorithm of how to do this. Uh We're looking at the baseline rate, the variations sorry, the variability, the accelerations and the decelerations. So we're looking at everything except for the contractions and the risks. When we, when we make this comment, they're just what we use to contextualize it. Um So it's the CPG is normal if all four of those things are reassuring. So no non reassuring features, no abnormal features, then the CCG is classed as suspicious if one of the features is non reassuring. Um But then you have to take into into account, do they have any risks of hypoxia? Um Are, are they under uterine tachysystole or hyper stimulation? Um And do they have any accelerations as well? Which would tell you that it probably is a reassuring CTG. Finally, uh it's classed as pathological if you have any two non reassuring features or any one abnormal feature. So that's why sinusoidal variability or uh a va variable deceleration lasting three minutes on their own, make it a pathological CTG. Um And then that, that warrants er intervention. Uh So like I said, reassuring you, you can continue the, the CVG or you can just stop there because you've shown there's no evidence of fetal hypoxia. If it's suspicious, then we recommend doing conservative uh measures. So this can be things like repositioning the woman, first of all. Uh So when, when you've got a, a highly gravid uh pregnant lady, um when she's lying, Supine, uh the uterus compress the, the abdominal aorta and the, the inferior vena cava and it affects the blood supply to the placenta. So that can induce hypoxia itself. So, it's important. Uh we normally recommend to, to lie on the left side. Uh so that we're compressing the aorta instead of the, the vena cava as it's uh higher pressure. Um We can also consider giving her fluids and if she's having uh an induced labor, uh then we can stop the Oxytocin, um which contracts the uterus uh or we can give tocolytics which are drugs to like tokos again to stop childbirth. Um or, or reduce the, the rate of the uterine contractions, things like terbutaline and Nifedipine. Um OK. So we can also, if it's pathological, we really want to get to the bottom of what is causing the EKG changes like I said it before, it can be due to things like maternal pyrexia. Um It can be due to cord compression. Um So it's not always due to fetal hypoxia itself. So, it's a point where you determine whether there really is hypoxia. And if we need to do uh quite a significant surgery by doing a Cesarean section. Uh So things we can do is an ultrasound which will come on to you a bit later. Uh We can do uh fetal pulse oximetry, uh sort of like a sa probe on the fetus or, or fetal blood sampling, uh which is an invasive procedure, but obviously not as much as ac section. So we're, we're really looking at the, the lactate and the ph of the arterial blood there uh to determine whether there is uh lactic acidosis in the fetus. Uh Finally, if there is um pathological uh a pathological CTG and evidence that it's due to hypoxia, then we want to do a, a category one Cesarean sections. This, this stands for the lower segment, cesarean section. Um And the category one is where we have to deliver the baby within the next 30 minutes because there's an imminent risk of fetal or maternal death. Um So, yeah, that's, that's how we interpret our CTG. Um It's important to remember that CTG S aren't the be all and end all. Like I said, there are other factors that can contribute to CTG changes, not just hypoxia. Uh So we're really looking at is the fetus hypoxic. But there are these other factors we have to rule out before we make that final diagnosis and intervene with uh with the labor. Um Also the, the features themselves aren't perfect. Uh So if we look at the table, uh we can see that abnormal decelerations are almost always present uh in fetal acidosis uh with a sensitivity of 95%. Uh But 50% of women who do have abnormal decelerations don't have any fetal acidosis. So, the these signs aren't necessarily indicative on their own. You have to interpret the whole picture. Um Look at the risk factors, look at the uterine contractions to work out if this really does warrant intervention. Um And there, there, there's also a little bit interoperative bias uh with the CTG. So different people will interpret the same CDG as being suspicious, being normal reassuring. Um So we only recommend to do a CTG if the woman has any of those risk factors in the first place. Um So normally what happens uh with the midwives is they'll listen to the, the fetal heart rate with something called a Pinard stethoscope, uh which this lady is using here. Um And they listen for a full minute to see if they hear any decelerations to measure the fetal heart rate. Um And you, you should also feel the mother's pulse at the same rate to make sure you're not hearing her heart rate. Um If they hear any decelerations, they have no way of telling if that is a late deceleration, an early deceleration, a variable deceleration. So at that point, you would get referred to the consultant led care um to have continuous CTG monitoring during the labor. Um The other thing we can do is use a Doppler, a handheld Doppler like this. Uh We'll see if the video plays now. Uh This is how we can listen to the fetal heart rates. Um Let complain. OK. So it, it produces a, a sound wave um that tells you how fast the the fetal heart rate is going and allows you to listen to it it does basically the same thing as the pin out stethoscope without having to put your, your ear close to the patient. Basically. Um OK. So that is how we interupt with our CTG S. Um If you do want more practice, we'll, we, we have some resources at the end uh for you to try at home um and work answers as well. Um But for now we'll move on to uh ultrasound um and how to read er those aster images that we we've all seen on pasted. Um So to start off with, we'll look at the machine again, it can be quite daunting uh on first inspection. Um So at the top, we obviously have the display uh showing us what the probe is sensing. Uh We've got a touch screen here which you can use to change settings, adjust the gain um and just choose which probe you're going to use. Uh We have the, the transabdominal probe here, which is the one you normally use during uh late pregnancy scanning uh which goes through the abdomen. Uh on the left hand side here, we have the transvaginal probe uh which is a lot more sensitive as you put it inside the vagina uh into the anterior or posterior fornix. Er and it gets a lot closer to the actual structures. You don't have to go through layers of fat and bladder and bowel to get to the actual structure we're looking at. So it's a lot more sensitive. Um But obviously it is an invasive test. Um And then here we have uh a, a very old school sort of ball mouse. Um And these buttons allow you to, to freeze the image and to print off the pictures for the month to take out. Um So there's the the main controls that you you should be aware of at this stage. Um So let's briefly talk about how they work and understand why we use the different probes. Um So whether or not you're using uh transabdominal uh which we have on the left side, which is curvilinear or the trans vaginal probe here. Uh They, they work by having an array of PS of electric crystals along them. So, along this way, and along this way, on the probe and those work by when you pass a current through them, they release ultrasonic waves. Um We use waves of 2 to 18 megahertz. Um those waves go into the tissues and then they're reflected back based on the acoustic impedance of the boundaries between the tissues, those uh electric waves come back to the crystals and when they vibrate at those frequencies, they again induce a, a current and then that is converted to the image that we see. Um So this is, it gives you a real time image without any radiation. Um And yeah, it's, it's an all round brilliant uh investigatory test. Um And it really should be used in other areas of medicine more than it is. Um So, let's see, you, you should be able to tell uh straight away by looking at your image whether you're looking at a transvaginal or tran transabdominal ultrasound transabdominal, uh the top of the image sort of follows the, the shape of the probe here and it's uh a lot less uh concave. Uh The transvaginal probe is almost a full semicircle here, um mimicking the, the shape of the probe there. And you can tell which way is up and down. Uh because you'll have a marker, it's usually on the top left on British machines, but it does vary. Um You'll have a mark here uh or this green mark here to tell you that that's the, the top of the probe. Um And that corresponds to a, a little mark that you hold when you do the ultrasound. So that's important here because uh the top of the transvaginal probe here is on the left hand side of the screen, uh which is something to remember. Uh So if we start off by looking at what's what's normal, uh This is how a transvaginal probe is inserted. Um As you remember from human reproduction, again, most women have an anteverted antiflex uterus where it is uh a face against the bladder uh in the, the antibotic position facing forward. Uh But some women will have a retro uh retroverted uterus where it's is more against the um and you can see from these diagrams that uh that changes the position of the, of the probe itself. Um So in the normal anteverted uterus, like I said, the top of the probe is where that dot is that green marker? You can see the top of the probe is uh closer to the front uh to the uterine fundus. So that's where the uterine fundus. Um So I should point out this is the uterus here, this uh shape here in the middle. We've got the vine cavity and uh a very thin endometrium, this lady. Um Yeah. So we've got the top of the uterine fundus here is anterior, it's closer to the top of the probe. A retroverted uterus, you can see the top of the probe is actually close to the cervix and the fundus is close to the bottom of the probe. So that's why on a retroverted uterus, you'll have the uterus the other way around. There's the uterine body there, here is the endometrium and here is the uterine fundus. Um Again, we have the market to make sure we are, this is the top side. So the top side is close to the cervix. So we know it's retroverted here and you get this in about 20% of women. So it is, it is quite common there. Um Yeah. OK. So let's move on to some pathology. So we'll start off by looking at pathologies of the myometrium, the muscular layer of the uterus. Uh So here we have a scan of adenomyosis. Um If you haven't heard of it yet, uh don't worry, it is uh a growth of endometrial glands within the muscular layer of the myometrium. So you have exogenous growth of endometrial glands, not in the endometrial tissue but separate inside the muscle itself and those exogenous glands are wide. We get this sort of classic, we call it a rain shower appearance. Um where you can see that there are shadows from the uterus because of the, the, the fluid in the endometrial glands, uh is a lot more dense. Um And we would describe it on the scan as hypo echogenic. So it's a lot darker on the scan. Um compared to say the endometrium, which is hyper echogenic, it's a lot brighter. Um And because we get this drastic change in the, the the density of the tissue uh that cuts off a lot of our sound waves, a lot of them get reflected back straight away. Um And so we, we lose the details behind structure as well. Uh So that's what produces some, it's called the venetian blind appearance because they're parallel lines. Uh I can put a rain shower on myself uh but use whatever term feels good to you. Um Other symptoms you might see um uh a really enlarged boggy uterus, um weird terminology again, but it just sort of means you can feel it giving way when you press on it. Um And they'll, they'll have sort of cyclical uh pelvic pain because it's quite strongly associated with endometriosis. Uh Lots of consultants consider it uh on the spectrum of endometriosis just affecting the, the uterine muscle uh rather than extra uh uterine structures as well. Um Another really common condition. Oh, sorry. And you can confirm uh whether or not you're looking at adenosis, confirm that they're endometrial glands by using what we uh a setting that we have on the ultrasound machine called color Doppler. Uh This is uh not necessarily er available at all NHS hospitals, but it is uh at all hospitals within our region, at least. Um And it shows you not the, the blood flow like a lot of people expect. Um but where there is movement of fluid either towards the screen or away from the screen. Um So you have a, a bar showing you on the left hand side where it's moving to we uh towards you, which is yellow away, which is red. Um And on other machines, it's usually uh a red and a blue color. Uh So it's often confused for sort of blood flow. Um But yeah, that confirms that there is uh fluid within these glands because the fluid is moving. Um And yeah, that, that confirms our diagnosis of adenomyosis here. Um ok. So yeah, moving on. There we go. Uh another really common condition that you'll see day in and day out is uh leiomyoma, which is uh the, the medical term for fibroids. Uh So, fibroids are benign tumors of the uterine muscle. Uh They're extremely common in women approaching the menopause uh as they grow in response to estrogen. And they're especially prevalent in women of Afro Carribean descent. Uh So on ultrasound, they look like this sort of well circumscribed, well circumscribed lesion here um with hypoechogenic tissue in the middle and they're, they're relatively homogenous. So there's no variation in the color really inside there. Um So this fibroids, as you can see is in a retroverted uterus again, because you got the cervix at the, the, the top side of the uterus uh and the fungus on the bottom side, sorry, the top side of the probe and the fungus on the bottom side of the probe. Um This image we have here is uh at one MRI. Uh but it also demonstrates how large uterus can get with multiple fibroids. So again, they're, they're hypo in intense on, on T one MRI. So this is a fibroid, this is a fibroid, this is a fibroid, this is a fibroid, this is a fibroid. Um So you, you can get multiple fibroids, especially in older women. Um They're again homogenous on MRI and we grade them according to the, the Figo grading system uh which is here. Um So they for, for our purposes um in exams you should know submucosal intramural and subserosal. Um So submucosal means that most of the fibroid is on the side of the mucosa or the endometrial tissue on the uterine cavity. Uh intramural means they're mostly inside or fully inside the wall. It's type four and subserosal means they're mostly uh against the, the cirrhosa on the outside of the uterus um or poking out a bit. Um So we can again confirm the the, the fibroid diagnosis using color Doppler ultrasound um to, to check for any blood flow within the mass. Um And this is more likely the colors that you'll see is what they use, where they have the, the red to blue scale with fluid moving towards you in red, away from you in blue. Um and fibroids shouldn't have any internal blood flow at all because they are just a smooth muscle mass. Um They may have some blood flow around them but not excessive um because they're not a fast growing tumor. Uh Other symptoms you'll get are menorrhagia. So heavy menstrual bleeding, uh an enlarged uterus, you'll get the, the uterus pushing on other structures. Uh So you may get uh urinary frequency, um painful uh sex. Uh So, dyspareunia, uh bloating after meals, um and rarely, um you'll probably only see it in plasma questions, but the tumors can produce uh erythropoietin. Uh So you can get a polycythemia uh secondary to that as sort of a not a paraneoplastic syndrome, but AAA benign syndrome that comes along with it. Uh However, in reality, you're much more likely to see uh an iron deficiency anemia than you are a polycythemia because uh they do result in heavy menstrual bleeding. Um ok. Yeah. So moving on, um that's the benign form of the tumor. Uh Very, very rarely you can get uh a leiomyosarcoma, uh which is uh a malignant tumor. Um They're quite similar to a fibroid on imaging that you have a well circumscribed lesion. But the, the crucial difference is it may have some um regions pointing out of it. So, not, not, not very well defined as a sphere. And y you, as you can probably appreciate here, you've got uh a lot of uh mixed echogenicity within it. So, the, the, the, the gray scale within the actual thyroid, which if I outline it here, that is all uh leiomyosarcoma. Uh there's a lot of different colors within it. Um It's mostly in postmenopausal women in contrast to fibroids, which are women at the end of their reproductive life. Uh because again, fibroids grow in response to estrogen. Uh leiomyosarcoma does not necessarily grow in response to estrogen. Um So, let's see, I think we've got a Doppler here. Yeah. So you can see here, crucial difference that you'd want to confirm every time you see a fibroid is that there's a lot more internal blood flow here because we've got a malignant tumor, it's growing very fast. Um So it needs a lot of nutrients. So we get that neovascularization. Um And we can see that on Doppler with a lot more uh moving fluid within the, the mass itself. Um OK. So next, uh those are the, the main uh pathologies in the muscular layer of the uterus that you should appreciate. Uh we'll move on to the endometrium. Next. Uh So we just remind ourselves of the, the menstrual cycle. Um It's into the follicular phase on the first half until ovulation. And then after that, we have the luteal phase when we have a corpus luteum, after the, the primary follicle has has ovulated. Um in terms of the endometrium, the appearance is uh on the bottom here. So, on the first few days, uh depending on the woman, uh we have the, the period or the secretory phase. Um Then we have proliferation of the endometrium where we're stacking on layers and it's increasingly thick each day, that's called the proliferative phase. And then after ovulation, we have the secretory phase. Um So broadly speaking, we're in the proliferative phase for the, the first half of the cycle, secretory phase for the second half of the cycle. OK. Uh So what does a normal endometrium look like? Um The reason we talked about this cycle is because it changes throughout the menstrual cycle. So, it's really important whenever you do a gyne ultrasound to ask the woman, when was the first day of her last menstrual period? Um So then you can sort of roughly place her into um onto that, that spectrum there. So early on um see, yeah, so early on uh in the early proliferative phase. So sort of day 567 of the cycle, uh we should have a really thin single layered endometrium. So the endometrium is this hyper echogenic layer in the middle of the uterus. Um It's a single layer in contrast to uh the, the, the early secretory phase uh where we have this classic triple layer appearance. So we still have the, the hyperechogenic layer in the middle where the endometrium on the front and the, the backside of the uterus meets. Uh what we also have this uh hypoechogenic layer on either side due to the, the actual endometrium. And we can see a hyperechogenic around that sandwiching it in which is the basal layer of the, the endometrium. Um So that occurs around day nine, give or take a couple of days depending on the length of the cycle. Um Then in the uh late cru phase, we, we get this really homogenous thick endometrium. Uh Right before we, we start menstruation. Uh So we, we've got build up of the endometrium and we, we've lost this triple layer appearance. It's all quite homogenous. Um OK. And it's also important to, to remember whether the woman is in uh premenopausal or postmenopausal stage of her life uh because we shouldn't get any endometrial proliferation after the menopause. Uh So any finding that the endometrium is thicker than four millimeters in a post menopausal woman should uh warrant a two week wait referral uh for hysteroscopy. Uh And why do we do that? Uh That's because we're worried about endometrial carcinoma. Um So this is uh yeah, the spinal ultrasound would be normal in a premenopausal woman in the late phase, but it was actually taken from a, a postmenopausal woman who was later diagnosed with endometrial carcinoma. Um Sorry, I'm sick. Uh uh endometrial carcinoma. Uh So, let's see. So, the, the British Gyn Cancer Society guidelines use uh a cut off of four millimeters um for the, the, the thickness of endometrium after which you should refer the woman to uh the hysteroscopy clinic, which is where, which is a camera test inside the uterus uh where they take a biopsy from the endometrium. Um Of those women who are referred with a uterus a an endometrium more than four millimeters uh that identifies 95% of cases and uh only incorrectly refers uh 47% of women. So it's, it's a relatively good cut off. Uh And this is the, the meta analysis that was looking at what is the best cut off uh for anyone interested. Uh It's a relatively common cancer. Um I think it's something like the, the fifth most common cancer in UK women. Uh So, somewhere around that region. So relatively high um effect on the NHS. Um and it's classically found in post menopausal women where we have that thickness of the endometrium. But it's important to remember that one in four cases do occur premenopausal. So that doesn't necessarily rule it out if we've got other pathological features. Um The main risk factor uh like a lot of gyne cancers is unopposed, estrogen. Um So you produce estrogen during your reproductive life uh predominantly. So, if you uh undergo menarche at the start of your first period, uh at an early age, you'll have a longer exposure to estrogen. Similar, if you have a late uh menopause, you'll have a longer uh exposure to estrogen and a higher risk of endometrial cancer. Um Yeah, other things that can increase the risk are things like obesity. Um as your adipose tissue secretes a bit of estrogen and uh Polycystic Ovarian syndrome, which is what you have. Uh We'll come on to it in a bit. Uh but you have hyperandrogenism and a lot of those androgens are converted to estrogen secondarily. Um So yeah, that's uh endometrial cancer. Uh moving on another really common finding like endometrial polyps uh which are outgrowths of endometrial tissue into the uterine cavity. Um They're quite a big problem for women who have them because they cause uh really significant menorrhagia, heavy menstrual bleeding and also intermenstrual bleeding. Um You can get it postmenopausally as well. Um So that can be another cause of people being referred uh under the the two week wait and then they'll have a hysteroscopy and find that they have a polyp instead. Um So they again grow in response to estrogen as they are endometrial tissue. Um And they have this classic sort of stalk at the bottom of them, attaching them to the rest of the endometrium. Um So they occur in older women uh predominantly uh but they can occur in premenopausal women as well. Um And yeah, it, it may look like a fibroid on, on first inspection. Uh So you can get a subserosal type zero fibroid that comes into the, the, the uterine cavity like this. Uh But again, we can confirm this using the color Doppler. So the endometrial polyp will always have this stalker supplying it with its blood. Uh Whereas the fibroid, as you said, has a little bit of external blood supply on Doppler but nothing internally. Um OK. So then we'll move, we've done the endometrium. Let's move on to the Adenexa uh which just describes all the structures uh around the uterus uh contained within uh the connective tissue of the broad ligament. So, really, it's talking about the ovaries, um the uterus sacral ligaments and the fallopian tubes here. Uh And we can visualize it just by taking a transvaginal probe, turning it to the side to see the, the right uh ovary and turning it to the other side, seeing the left ovary. Um You should always check that both ovaries are there. Um and assess both of uh both of them in detail during a scan. Uh So this is what normal ovaries look like. You'll normally have a few uh actual follicles uh around the outside and you may have one dominant follicle here. Um Or you may not have one at all. Uh You should only already have one dominant follicle in each woman. So one in one ovary zero in the other. Uh because that's the one that has ovulated during that cycle, it's completely normal, not to have it as well. Cos it might have regressed at, at that stage while you're doing the scan. Um Yeah. OK. So then moving on, we can also do Doppler uh normal ovaries have uh blood supply around them like this and very little stromal uh blood supply. Um So that's what it would normally look like. Uh The main condition that you will see is Polycystic Ovaries. Uh not just if you go into, but every single day of practice uh until you retire, uh Polycystic Ovarian syndrome affects um I think it's one in five UK women. Uh It's, I'm sorry, one in 10 UK women. Um It's just as common as asthma, uh just as common as diabetes in UK women. Um But it's criminally underdiagnosed. Um So you will see women with this every single day of your life. Um until, until you retire. Um So yeah, we, we diagnose it using the, the Rotterdam criteria which states that a woman with Polycystic Ovarian Syndrome uh has two of these three factors. So, hyperandrogenism, high levels of testosterone, uh either confirmed for the blood test or by uh clinical signs. Things like uh facial hair, uh excessive uh body hair, uh oligomenorrhea, which is where her periods are at least 35 days apart or longer. Or if she's amenorrheic doesn't have any periods and if she has Polycystic ovaries on ultrasound, so you don't actually need Polycystic ovaries to be diagnosed with Polycystic Ovarian syndrome. Um But yeah, this is what Polycystic Ovaries look like. So again, we can see we have a lot more um follicles um rather than just three or four antral follicles. And classically, they line up around the outside of the ovary doing it this uh what we call a pearl necklace appearance. Um And for it to count as polycystic ovaries, you have to have at least 12 follicles in a single ovary measuring 2 to 9 millimeters across. Um or you can measure the, the volume of the whole ovary as being more than uh 10 centimeters cubed. Um Yeah. So everyone that's uh has clinical signs of Polycystic ovaries should really be referred for, for an ultrasound to assess uh the, the ovaries for any uh polycystic appearance. Um Another really common condition is uh ovarian cysts. Uh There's quite a few different types. Uh So this here is uh a uh chocolate or en endometrioid cyst. Um and the way we can tell that is we've got the ovary, we've got a well circumscribed lesion. It's hypo echo echogenic. Um And when we do the color Doppler, we see that there's no bleeding within it. Um The classic variant is this sort of reticular ground glass opacity within the ovary. Um And that tells us that there are, that there are blood products within there. Um So you're seeing the, the boundaries between different pieces of blood. Um and the, the, the color Doppler tells us that that bleeding isn't active. So it's just blood that's sitting there. Um And that, that's strongly linked with uh endometriosis there. Uh So it's endometriosis of your ovary. They're called chocolate cysts because when you drain them on a laparoscopy, it comes out like chocolate sauce. Um Yeah. Ok. So moving on, uh you can also get dermoid cysts of your ovaries. Um They're quite common on in head and neck as well. Uh But in the ovaries, this is how they look, they'll have this hypoechogenic space in the middle, uh which isn't always filled with fluid. It can just be uh a collapsed face can be filled with serious food like this. And you'll have this classic Roans er nodule, which represents the dermoid plug from which the other uh normal body tissues grow from. So things like hair and teeth and bone can grow inside them. Um So they, they have this really mixed appearance in the nodule and then sort of this empty space around it. Um Then you can have simple ovarian cysts as well, uh which is just filled with serous fluids. Uh nice single space, uh no uh ho homogenously hypoechogenic. Um And they can indicate that you have an ovarian cancer if they have any of these uh nasty features. So, like I said, unilocular, no solid components, just hypoechogenic within it indicates it's likely a serous ovarian cyst. Uh nasty features are things like solid components, uh nodules in the walls, uh blood products within which again gives you those c ground glass opacities. Uh or if they have uh multilocular cysts which can indicate an ovarian cancer like cyst adenocarcinoma. Um see uh then a couple more uh things to assess you normally shouldn't be able to see the fallopian tubes uh in the adnexa. Uh They're, they're normally not picked up by ultrasound. Uh But if you can uh you get this sort of uh bubbly appearance, it almost looks like colon, um which is where you have hydrosalpinx. So that just means that fluid in the floating tube. Uh and the most common cause of that is uh chronic pelvic inflammatory disease uh caused by uh either chlamydia or TB. Um And you get these sort of cystic lesions uh on longitudinal section uh on transverse section, we call it a cogwheel appearance because you get these indentations. Uh And again, we, we want to check that for any, any active bleeding with a, with a color Doppler there. Um Yeah. Ok. So these women will often have uh intense uh pelvic pain, chronically, not necessarily related to their periods. Uh because of the chronic infection here and they classically have subfertility as well. Um Yeah, finally, um the last adnexal pathology we look at is ectopic pregnancy, um which is where we have uh a non viable pregnancy implanted in a location outside of the uterus. Uh So the most common place is the ampulla of the fallopian tube and this presents uh it presents quite early, uh definitely before 10 weeks gestation. Um So we don't have time for the, the to develop fully. All we can see is the uh Ys developing and you might get the pole here developing as well. Um But if you have any woman coming in pregnancy test just to rule out. Uh um OK, so that is all of the uh gyne ultrasound that we'll be doing. Um just uh to let you know, we do, we do have a look at the fetus. Um But if you do have to head off at this point, uh here is the, the QR code to, to fill out the feedback. And if you fill it out at the end, you can put in your email to get sent uh a copy of the, the, the short answer question uh past paper questions. Uh All, all out CDG has a practice and Gyne ultrasounds and some extra things as well. Um So yeah, there's the, the link for, for that. Uh if you want to screenshot uh if you do wanna stay for the, you have surgical ultrasound, I'll be going through that uh right now. Ok. And I'll pop this back up at the end as well. Um The staying. Um ok, so moving on to uh the fetus uh which is something that you will be doing for your maternal health placements. Um, every woman in the NHS who falls pregnant should be offered uh two ultrasounds at a minimum. Uh There's uh a dating scan which happens at uh between 10 and uh 14 weeks. Uh So some, it's called the 12 week scan and that's to tell you the, the sex and the age of the fetus and to look for any abnormalities that we can treat straight away. Uh Then thi thi this year is a, a healthy, uh 12 week scan, er, a dating scan. The other scan they should have is at 20 weeks, um, or between 18 and 21. Uh And that's the anomaly scan where we look for things like Down Syndrome and a lot of other pathologies which will go through now, um, that come up quite frequently in the, the Sa Qs. Um So, yeah, we'll, we'll look at uh all the things that get checked on the dating scan, um, on the left hand side here and we'll go through some really common pathologies that you don't want to miss uh in your exams. So here, the first thing we want to check is the, the skull and the brain. Uh So this is what a normal transverse section of the fetal brain looks like. At 12 weeks, we have these sort of two kidney bean shapes representing the, the two ventricles, uh the two hemispheres of the brain. And we have the falx cerebri in the middle separating them, which shows us that we've crucially got two separate uh halves of the brain. Uh That's what it looks like normally. Um There is a condition where we don't have the separation in the middle uh called holoprosencephaly, which means you have a single uh frontal lobe uh without the separation. Uh And that gives you this classic sort of butterfly sign uh without any falx cerebra in the middle. Uh and it produces quite a spectrum of um manifestations if the baby survives, but most of them are uh fatal in utero. Uh And this causes sort of this er cyclo cyclopedia um that you may have remembered from embryology of first year. Um Yeah. OK. So that's the, the main thing with the skull uh moving on to the, the neutral translucency, which is this area of uh it's not actually part of the CSF but it's uh an area of soft tissue edema uh behind the back of the neck and thickenings in the neutral translucency um are strongly associated with several uh diseases. Um So it's considered abnormal if it's above the, the 95th centile. Uh So we have these standard charts based on the, the height of the baby, the crown, on the length and how thick their neutral translucency is. So, if they're above the 95th percentile, it's considered abnormal. Uh So this is an example of a really abnormal one here. This is clearly uh bigger than 90 percentile, a lot of edema. Um And this is actually a case of cystic fibroma, which is uh a cystic neck lump uh in the fetus. Uh But it's the, it's also really commonly associated with uh all of the triazo. So, uh Down Syndrome, Edwards Syndrome, Patau syndrome, um as, as, as well as some other things. But those are the, those are the main things to think of. Uh when you see a thick neutral translucency. Uh Next, you'll want to assess the heart. Uh cos you'll be very aware of all the, the the heart pathologies like to charge you of fallow transposition of great vessels. Um So we do a what we call a four chamber view where we can see here, the left side of the heart atrium ventricle, the right side there atrium ventricle and there we also have the, the p pulmonary vein. Um And when you're doing it, it's obviously in real time, II, don't think this is gonna work now either. Um Yeah, it will be in real time. You can see the valves contracting and assess the blood flow and also use that color Doppler to s to see where the blood is going and see if there, there are any uh septal defects um or any other abnormalities. Um Yeah. Ok. So then we want to assess the abdominal wall as well. Um So you'll remember that in normal development, uh the bowel starts growing a lot faster than the abdominal cavity does. And by week eight, it starts to protrude out um of the front of the abdomen, uh before the abdomen starts to catch up. Um And the, the intestines come back in after rotating, which gives us a, a normal position. Uh by about week 13. Uh So here we have a nine week fetus, this is the yolk sac, this is the fetal pole. And here we have the, the bowel protruding out at this stage in development that's completely normal. Um So it's called a physiological bowel herniation if we get to a later stage like the 20 week scan and we still see it. Um Then that's pathological. It should have come back in by then. Uh So this, you might remember is an umbilical hernia or an omphalocele, uh where the bowel is contained within a membrane that's still protruding out of the umbilicus. Uh And we can confirm that uh using color Doppler again, very useful tool. So this shows the uh portal vein going into the mass here. So it's a herniation of the liver into the, into the omphalocele. Ok. And this case here is again, we've got the fetus and transverse section here. We can see a very clear out pouching here um without a membrane over it. Uh So this is uh a case of gastroschisis. Uh same thing again, but instead of out of the umbilicus, uh the bowel protrudes out of the right side of the abdomen, um protrudes out the right side of the abdomen, uh without any membrane over it. So, at birth, that causes uh very different presentation. So we've got some on the left clear membrane, gastro gastroschisis on the right without the membrane. Uh So this needs uh immediate surgery. Uh Whereas uh this side, the omphalocele can be managed expectantly initially if it's on the smaller side. So it doesn't necessitate surgery uh next to the bladder. Um So this is really important because uh a common abnormality is agenesis of the kidneys where you don't get any kidney development. Um So, so that means you don't get any urine production. Uh And you might remember that uh the the, the fetus normally swallows, amniotic fluid, excretes it as urine. Um And uh that's, that's how it uh starts to develop its urinary system. Uh So you can get a, a normal bladder here. Um Here we have uh actually a distal blockage of the urethra, ureth urethra, um giving us AAA bladder, which is more than a 90 percentile. So we call this a megacystis uh or big bladder. Um Yeah. Ok. So then uh what do we have here? So here, we can see this is the uh longitudinal section here, the coronal section um of the, the kidneys uh which you also want to assess, you want to make sure they have both kidneys. So this is one kidney here, you can see that sort of uh shape of the renal pelvis. This is the other kidney here. Um and this is actually a case of hydronephrosis. So where there's fluid backed up to the kidneys and they've swollen up uh because of an ob obstruction. Um So the, the renal pelvis is really swollen. Uh Normally it would be a lot smaller than that, but it would still have the same shape uh moving on to the limbs. Uh We want to check uh for the, the, the stylopod and the Zygo pod. So the uh humerus, the ulnar and radius in the arm and in the leg, we want to check for the uh the femur, the, the tibia and the fibula. Uh at the 20 week scan, we'd also check that they have all five digits on each hand and foot. Um So the main thing we're looking for there that you should be aware of is uh something called club foot. Um or on the exam, it will be called congenital Talipes Echovirus So, all that means is the foot is excessively sated inwards and it sort of looks like this on the ultrasound. It's the, the, the foot is bent in here. Um That's important because it's associated with uh Trisomy 18 Edwards syndrome. Um, and it requires really urgent um, corrective uh, splinting and casting once the baby is born within sort of the first two weeks. Uh So if we're not aware of it, we can't get those um things in place. But when the baby arrives, um moving on, uh looking at the placenta as well, we want to know where the placenta is. Uh So here we have uh you can see it's this hyper echogenic mass here. Um That doesn't continue all the way around the, the uterine wall, which is this hypoechogenic piece here. Uh So this is the placenta on the top scan, this is the placenta on the bottom scan. Uh And you can see the uterus continues around it, the placenta stops right there. Uh Here, we actually have the, the cervix. Uh So the placenta in this case, is covering the cervix. Uh And that's a really important finding. Uh So that's called placenta Praevia, uh which is graded from 1 to 4 depending on how uh badly it covers the uh the birth canal or the cervix. Um This is uh a grade three or four because it covers the uh internal loss of the cervix completely and will ne necessitate uh an elective cesarean section because the baby can't pass over the, the placenta without causing excessive bleeding and having a risk of maternal hemorrhage. Um So that would, that finding would necessitate uh a Cesarean section. So, really important to note. Uh Here we go. Uh with another case of previa, uh this is sort of ac shaped one. So within the plane of the ultrasound, the placenta is here, it goes back around and then it comes back into plane here. So it is sort of around the area of the internal os here which you can locate by uh where the cervix is. Uh So again, this would be a category three or 4% previa and would necessitate um a cesarean section um if it was found. So yeah, we have grade one up here where it is in the lower uterine segment, grade two where it touches but does not cover grade three where it covers. But when we dilate during labor, it might move away and grade four where it completely covers. OK. Uh And then finally, we want to do some measurements to make sure that the baby is growing properly. Um So here we, we do five measurements. We do the circumference of the skull, the biparietal diameter. Next. Uh we also do the abdominal uh circumference which is done at the level of the stomach here. Uh the upper li vein here and the portal sinus. So this will be in the liver, uh both of these structures and the stomach here. Uh So that's how we know we're at the right level. Uh We also measure the femur uh from the hyperechogenic uh diaphysis on one end to the hyperechogenic dialysis. On the other end, we don't include the growth plates, which are these sort of hypoechogenic bits on either end. Uh And finally, you want to the, the crown rump length, uh which is effectively the height of the baby uh in this sort of flexed position. Uh And that's also the same position. You want to measure the neutral translucency there. Um If the, again, we want to plot the those sizes um on uh a growth chart to work out the center of their growth. Um The main ones that we're focused on the head circumference and the abdominal circum circumference. Uh because if the baby has uh intrauterine growth restriction, uh we'd expect these uh to be uh below the, the second centile. Um So we take a ratio between the head and the abdominal circumference. If that is above normal, we say they have asymmetrical growth restriction because they, they have reduced nutrients and they have to prioritize the growth of the brain and the head over that of the abdominal organs. So the head decreases at a slower rate versus the abdomen, which is really slowed down completely there. Um So that would be an asymmetric growth restriction and that tells us that you've got um an external factor uh limiting the, the growth of the baby. Uh so reduced nutrients from the placenta, um or uh hypoxia long term can cause that. Um if you, so this is what, again, what a a intrauterine growth restricted baby looks like compared to a normal baby. If we have a symmetric uh growth restriction where they, they both slow down to a similar center and you have a, a normal ratio between the head and the abdomen that tells you that the, the head isn't being prioritized over the abdomen, the baby is just small overall. Uh so that can be a normal finding in smaller women uh in certain ethnicities. Um But if it is sign that it's pathological, then uh it's due to intrinsic factors like genetics. Um and the baby's individual makeup um rather than an external factor are like an asymmetrical. Uh on the other side of things, the baby can be very large uh like this little guy here. Um If they're above the 90th centile, they're called large for gestational age. If they're above 4 kg at birth, we call them macrosomic babies. Um And the main respects for those are diabetes and maternal obesity. Um OK. And there are some extra things to do at the 20 week scan. Uh But I think I'll stop it there just so we have some time for questions. Um but I'll upload the slides uh to the Google Drive as Well, uh, so again, uh, if we really appreciate it, if you could fill out the feedback and you'll be, uh, quickly rewarded by, uh, some past paper questions to practice your Sa Qs and some work answers. Um, but yeah, if anyone has any questions, uh, please, uh, ask away. I see we've got some in the chat.