Twin ultrasound

#KnowledgeIsSuccess and in the first weeks of pregnancy it is possible to distinguish if a twin pregnancy began in a single embryo that later divided into two or if from the beginning they were two completely independent embryos… Dr. Carlos Monsalve, expert in maternal care Creafam fetal shares with us this ultrasound from week 24 of a monochorionic diamniotic twin pregnancy (a single placenta but two amniotic sacs) in which the main concern would be the existence of a fetus-fetus transfusion syndrome.

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Hello, how are you, very good afternoon, again with you showing you cases that we have here at Creafam, now we are going to present you a video of a twin pregnancy. She came to us when she was already 15 weeks so sometimes it is very difficult to know if it is a twin pregnancy or if it is a twin pregnancy. When they are identical twins, they are those babies that come out of a single sac in which the fertilized egg divided by two sperm and in a single sac, 2 babies were formed, OK? When it is a dichorionic or diamniotic pregnancy, what we call it is when there are two sacs that are implanted at the same time, that is, two eggs, each fertilized by its sperm and implanted at the same time in the mother and that is when they are the buddies that we know and identical twins are when they come from a single egg. This is a case where it is a twin pregnancy that arrived with us at week 15, so sometimes it is not possible to define very well if they came in a single bag or if they were one that worked. Why do I say this? Because in this case it is a single twin pregnancy where the placenta is a single placenta that feeds the two babies but if they are divided by a membrane, then it is what we call a monochorionic diamniotic twin pregnancy, that is, each one has its own sac but They feed on the same placenta.

Why is this case interesting? Because here we have to be very aware that babies do not grow in a very different way. Yes, it is very common to have a twin pregnancy, one being a little bigger than the other, but especially in the first trimester, second trimester, it is important to see that there is no There is a lot of difference between you and the babies. In this case, there is already a difference of almost two weeks of pregnancy, so we have to be very careful that there is not going to be a fetus-fetus transfusion where there are very classic signs on the ultrasound to identify if it is passing blood from one baby to the other or it is simply one that is eating less than the other. This is a case where one baby is eating less than the other. What happens in those where there is a fetal transfusion? That is a more delicate, more serious issue where there is data… For example, the one who is donating the blood becomes very small, he remains small, he does not grow because he does not receive as much blood supply and the other, who is All the blood goes because he is a very big baby but it is also very dangerous in both because in one his heart is overloaded and in the other he is not eating and there the difference is very wide between the babies. If there are techniques to improve them, it is through laser, the 2 placentas are separated and the babies have a very good prognosis.

In this case it is not the case of fetus-fetus transfusion, but if it is the case where one baby is growing less than the other, then it is important to continue carrying them, they are now 26 weeks old, the video you are going to see She is 24 weeks and four days old, now she is 26 weeks and 4 days old and continues with that same difference, not increasing to more than two weeks. A very serious problem would be when there is a difference of more than two weeks between one and the other. That is not the case here, so I believe that this patient of ours will have a very good prognosis.

Twin Ultrasound begins

Let’s see if the liquid, the growth, is really decreasing, how are they, right? In babies, in twins, one will always be bigger than the other, the important thing is that there does not begin to be much difference between the two, that they are not separated by more than two weeks. Look, this is the exit and this is the little twin and this is the other’s little head. This one here goes up here, they all look close together. We already know the sex, right? Girls? and here’s the other one over here, here he’s going to put both of their little legs together. One that is here, this is the head. And here is the other head together, look how attached they are. Well let’s start. Which one did we have as twin 1? The one that was bigger? Which is this one here. And the one down here now is the one that looks smaller, and this is the one that looks a little bigger. His gastric chamber and his gastric chamber in both.

Do you remember when I told you that when there is a fetus-to-fetus transfusion you have to make sure that it also includes their bladders. The bladder and the bladder here, here is one’s and here is the bladder of 2 here, so let’s measure… We start by listening to the heart. He hears very well, he moves with a good rhythm and he has a heart rate of 143, which is normal, between 120 and 160. This is the little head seen from above, the crown. That goes from one temple to the other… BPD 56.2 Head circumference 215.6, good. This is the belly. And the abdominal circumference, this one that looks a little bigger and the black circle, the stomach. Abdominal circumference 185.7 and these are the legs, here the pelvis, this is his thigh, the femur, the butt and the other femur and this is the bone of the leg that we are going to measure… If you see this leg it looks a little bit bigger big one from here. Femur 42.8, good. The amount of liquid that is all black looks good. The little face, well, you can’t see it well because it looks like it is, looking inwards, and the little sister who is looking up a little bit, you can see it, here they are looking at each other.

About fetus-fetus transfusion syndrome or heart study

Let’s now measure the other twin. This is twin 2, which is the one that is a little smaller. It goes, from one temple to the other: DBP 53.8 Head circumference 198.5 This is the belly that does look a little smaller but now we see how much, the belly of twin 2 compared to the belly of twin 1 if you see a a little smaller. There is also your stomach and this is the abdominal circumference. Abdominal circumference 162.8 equal and this is his leg bone, the femur. Femur: 38.1 And also, the liquid is looking good, okay?

This is the umbilical cord and here we see the flow. A normal flow is seen. For the weeks that it has this normal IP: 1.66 IR: 0.84 The placenta, this is where the two placentas join, the placenta is one, that is why it is monochorionic, because it is a single placenta that is feeding the 2 babies but they have its two cords. Each one with its cord but from the same placenta, so since it is the same placenta it is normal for one to be bigger than the other, look, twin 1… Twin 1 weighs 611 grams and corresponds to 23 weeks and 3 days, okay? ? Twin 2 weighs 451 grams and corresponds to 22 weeks, that is, the difference is 10 days between one and the other. If there is a difference but it is not something exaggerated, it is as if it were a grade 1 restriction, I do not see what if, for example, I do not see data that it is a severe restriction. As long as it is kept for less than two weeks it can be considered normal to a certain extent and it is important to see the bladders, here is the one from twin 1, here is the one from twin 2. I put it here and here it is, if it is bigger it is the twin 1 than the twin 2 but I really don’t see a difference yet to worry about.

It can happen? Yes, it can happen, but it can also happen that they remain there with that difference and as long as the biophysical profile of the babies is adequate, that is, they have good movements at their own pace but continue to grow, they do not stop because there will be no No problem, the problem is when there begins to be a very, very marked difference and right now the difference is 10 days, which is not something so marked, okay?

The baby with clubfoot

– Regarding your little foot?
– Let’s see… It was the twin’s
– The biggest
-Right now I’m telling you, look, here’s her little foot. Right now I’m telling you…

Light, it’s this one look, it’s this one here. Do you see the foot here? There’s a little bit here, here. Do you see it? this little foot And on the other side, it’s not a club foot as such, huh? You can only see it here, the one on this side does look a little more rotated. And the one on this side, the foot looks completely normal, it’s just one foot, this one here. Do you see how it arrives? Because here comes the leg, comes the leg and see how it gets in here. This foot is what is called clubfoot, now, don’t worry, currently with the treatments available they are doing very well. Look, it’s on this little foot here. But we will be seeing that, because as I say, of the risks this would be the smallest, the greatest would be the restriction of the growth of the smallest. This is where you see this little foot, it kind of looks half turned around.

Well, the problem here with 3D is that they are very close together, look, how are we going to see his face? Here at 2 at the same time. Here it is, if I put the 4D here, it is very close to its sister and to the walls of the uterus, so you cannot see the little face, it looks like there is a lot of interference and you cannot see it well formed… It’s not that it’s not well formed, it’s that it’s here stuck to the walls of the uterus here and this baby here is looking down here, see? Here you can see the forehead, eye, eye, nose, the little mouth and the other one is stuck here. But to see them we would need them to separate a little. That’s the problem with 3D, 4D, it would have been good here… Here you can see the difference in the size of one face with that of the other, right? As if it looks bigger, the difference is 10 days. So, we have to wait a couple of weeks to see if that difference doesn’t widen… That’s how they have been… With 10 days, 2 weeks apart, now I’m going to see how much they weighed before and how much they weigh now and how much the current difference okay? -Yes, since that time we came, thank God it has remained there.

– They have been maintaining themselves.

For example, the face, but it looks very squashed, here is where the nose would be, here the mouth, the eye and this is the forehead but all that distorts because it is his sister. It doesn’t help much for the photos. Now we’ll see how we go. OK?


Well… As you saw in this study, the two babies are doing very well, we already know the sex, they are two girls, so the important thing here is to see the patient every two weeks maximum every three weeks and then after week 31 every week Why? Because if there can begin to be more difference from week 28, then it is very important that we carry out checks every week to see that there is no difference in growth between both babies.

In this case, I believe that they will remain like this with a difference of one week, ten days, and don’t worry about that because it will take us to the end, the goal will be week 36. We also had a case from a long time ago, of some triplets where one had only one artery in the umbilical cord, commonly when this is the case they are smaller because it makes it more difficult for them to pass blood, in this particular case it was the one that had the best weight, so don’t worry about the important thing It is having good control, good follow-up and being very attentive to these babies so that they reach a good end, thank you very much.

“It is common for twins to have a slight difference in size, only if the difference becomes greater than 2 weeks would it be necessary to intervene by dividing the placenta using a laser”

Dr. Carlos Monsalve
Dr. Carlos Monsalve
Specialist in gynecology and obstetrics

Perinatology, invasive techniques and obstetric ultrasound.
Hospital Universitario La Fe, Valencia, España.

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