Nuchal Cords, or babies born with their umbilical cords wrapped once or more around their necks, is a commonly discussed fear among pregnant mothers. It's something that mothers often comment about to me when we discuss their hopes for their births. They say things like "I hope the baby is born healthy, with no complications like the cord being around it's neck." You wouldn't believe how many women say to me "...it was an emergency because the cord was around her neck and strangling her!"
While it may have been an emergency, and the cord may have been around the baby's neck, correlation doesn't always prove causation. According to a Cochrane study, over a quarter of all births, and maybe more, are babies born with a cord wrapped around their necks; because babies aren't yet breathing through their trachea, this isn't usually a cause for concern. Babies are very active in the womb, and early on, they begin to turn, flip and wiggle pretty often. This causes them to get caught up in all sorts of ways in their own umbilical cord. Among the births that I have personally attended, the number of times I have watched a midwife effortlessly slide the cord up over the babies head after delivery, outnumbers the times I've seen a baby born before getting a peak of their cord.
This, to me, is one of the biggest fear mongering tactics used to scare mothers into thinking about the dangers of birth. There have been numerous studies on the unaffected, positive perinatal outcomes of babies born with their cord wrapped around their neck. So when does it get tricky? When can there really be danger, and what does it depend on?
Firstly, there are a number of things that can cause wavering heart rates in babies on electronic fetal monitors during labor. For example, high levels of Pitocin usage, length of the umbilical cord, position of the baby, position of the mother, and so on; and don't get me started on false positives- (the doctors who invented EFM are famous for stating they regret the invention because of it's over-usage, and not leading to better birth outcomes,) but we can go into details about those in another post.
Today, let's talk about what matters in a Nuchal Cord. The first thing that sometimes matters is the length of the umbilical cord. I have in the past attended births where the baby's cord was so short that when the baby was lifted after birth to be put on her mother's chest, the cord only barely stretched to reach her mother's lower belly. In these cases I very rarely saw any problems present themselves in the actual birth. I have also though attended two cesareans where each contraction caused the babies heart rate to drop on the monitor, and once the baby was born, we saw the cord gave it little to no room to wiggle, without bending the baby at a dangerous angle. The cord can sometimes have an effect on pulling back a baby who is trying very hard to exit the womb, whether it be around the baby's neck or not.
Another factor is the tightness of the cord. In most circumstances, as the baby's head is born, the midwife is able to quickly slip the cord off of the baby's neck, releasing the pressure. There are few cases where the cord is too tight and this becomes difficult.
One last factor I'll discuss today is the knots that sometimes develop in the cord. While the cord wont be "choking" the baby per say, it could cut off it's own circulation depending on the tightness around the neck, or the development of a knot- therefor preventing oxygenation of the fetus. While this is scary, it is NOT the most common Nuchal Cord, and many cords have harmless knots as well.
As mentioned above, most of the births that I have attended occurred with a Nuchal Cord present. Aside from my anecdotal experience, evidence shows that the majority of Nuchal Cord births are far from dangerous, but rather a common occurrence. Your baby only has so much space to move; the real miracle is that so many babies still manage to stay out of "trouble" with their cords, and come out long before we see their cord present.
Remember to keep in mind other factors that may have effected labor when friends claim their babies lives were threatened by Nuchal Cords. It's not impossible, but it's unlikely considering the evidence.
If you have any questions about this post or others, please feel free to reach out!