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This is a transcription of a portion of a Healthful Woman podcast.

Shelby’s Question

“Hi, Dr. Fox. We just had our 20-week scan, and velamentous cord insertion was found during the ultrasound. Everything I’m reading online points to a C-section being a high outcome for most velamentous cord insertion cases. I would love your expert opinion on it, if that is the case, based on what you know. Thank you.”

Dr. Fox’s Answer

Good question, Shelby. I’m going to disagree with Google on this one, and I don’t think that velamentous cord insertion significantly increases the risk of C-section. Okay, so that’s the short answer to your question, but let’s back up. So, what is velamentous cord insertion? Essentially, when you’re pregnant, the baby inside has an umbilical cord that starts at its belly button and goes to the placenta, which is attached to the uterus. And that’s essentially the lifeline for the baby. The placenta attaches to the uterus. Nutrients, oxygen, and fluids come through there, through the umbilical cord into the baby, and then the baby’s waste products through the cord back to the placenta. Whenever we look at an ultrasound and everything, we look at how the umbilical cord inserts into the baby, right? We refer to that as umbilical cord insertion, and certain issues can occur with it. We also examine how the umbilical cord attaches to the placenta, which we refer to as the placental cord insertion. And usually, the cord sort of plunks right into the middle of the placenta, think the middle of a bullseye. And that is the typical or near the middle of the bullseye, and that’s fine.

There is a situation where instead of going into the middle, it inserts more towards the periphery of the placenta, and different definitions for that, but we usually call that a marginal cord insertion, which is its own topic, whether it does or does not have significance, and that’s debatable. Then there’s a situation where the cord, if you think about it, basically, let’s say, misses the placenta and inserts not into the bulk of the placenta, but a little bit off to the side into the membranes, into like the clear saran wrap type of thing, and inserts there. And then the blood vessels from the cord travel in those membranes, and then they go into the placenta. So the cord and the placenta, the blood vessels are connected, meaning there is connection to the blood flow and there’s nutrients going back and forth, but instead of the cord going directly into the placenta, there’s like a space between the placenta and the cord where there’s just a clear saran wrap membrane and the blood vessels going in both directions, and we call that a velamentous cord insertion.

So does it matter? If you look at studies that have evaluated pregnancies with velamentous cord insertion, there are some increased risks in those pregnancies compared to pregnancies where there is no velamentous cord insertion. Some of those risks might be related to just the physical fact that there are these blood vessels that are exposed, so to speak, meaning they’re not within the cord, they’re not within the placenta, they’re sort of traveling between the two. It could also be that any placenta and cord that’s built differently is also at risk of not functioning perfectly. When we see someone with a velamentous cord insertion on ultrasound, I tell them that, for most people, there will be no impact whatsoever. You wouldn’t know you had this, there’d be no impact on the baby, no impact on the mother, no impact on your labor, no impact on anything. That’s what happens for most people.

But there is a slightly higher risk of certain complications in pregnancy. Exactly how much higher depends on the person and the circumstances. Things like fetal growth restriction, will the baby grow well? Again, that’s probably more related to velamentous cord, which might be a sign that there’s something off with the placenta to begin with. It’s not so much that the nutrients can’t flow through those blood vessels, but that’s one thing we look for. Then there’s also this potential that in labor, right, since those blood vessels are not protected in the cord and not sort of within the placenta, there’s a concern that in labor, they can easily get compressed. When that happens in labor, the baby’s heart rate drops, and that could lead to an increased risk of a C-section. However, I would say it’s not the majority; it’s just slightly higher than someone else. So when we see this, I tell people when you’re in labor, it’s possible that you have a higher chance of the baby’s heart rate dropping with contractions, and you will need a C-section, but I would not tell them it’s more likely than not or probable or anything like that.

There is one other situation where velamentous cord is potentially an issue and that’s if coincidentally that area where the blood vessels are traveling between the cord and placenta also overlies the cervix, it just happens to be in that location, that would be something called the vasa previa where the blood vessels are going right over the cervix which has its own set of risks. We’ve done other podcasts on that. But assuming those blood vessels, and if you had a vasa previa, you would definitely need a C-section. But assuming the blood vessels don’t cross over the cervix and all you have, so to speak, is a typical velamentous cord insertion, what I would say is there are some risks. Most of the time, it means nothing; we just watch a little bit closer, and there is probably a slightly higher risk of a C-section, but I would not say that most people will need a C-section because of it. Once the baby is born and the placenta is out, it has no effect on anybody, the baby, or the mother. This is just an issue during pregnancy, the placenta.

Carnegie Imaging for Women blogs are intended for educational purposes only and do not replace certified professional care. Medical conditions vary and change frequently. Please ask your doctor any questions you may have regarding your condition to receive a proper diagnosis or risk analysis. Thank you!