For many years, common obstetrical practice was to clamp and cut the umbilical cord as soon as possible after birth. This practice was often thought to be best because it was feared an infant could lose blood volume through the cord, into the placenta, and suffer anemia, dangerously low blood pressure, or death. More recently scientific opinion is moving in a direction that many natural minded people have believed was best for years; to wait until the cord has stopped pulsing before clamping and cutting it. Why is this?
There is evidence that delaying clamping the cord is beneficial in some ways for the newborn infant. Contrary to more traditional obstetrical belief, the blood vessels in the cord are not an open conduit, but rather, an active combination of arteries and veins with smooth muscle walls capable of contraction, much like arteries elsewhere in the human body. Smooth muscle facilitates one way movement of blood, aided by the force behind blood ejected from the heart. Thus, an unclamped cord will circulate blood in an appropriate manner between the placenta and the baby and not passively drain from the infant. In fact, a pulsating cord in the first few minutes after birth delivers a significant volume of blood to the infant (up to 100 mL) which helps establish iron stores in the baby meant to sustain them through the first year of life.
Thus delayed cord clamping is seen to be of benefit to the long term health of the baby. One small randomized controlled trial with mothers who were anemic during their pregnancies highlights this, since anemic women frequently give birth to anemic babies (or babies who are more susceptible to anemia):
Haemoglobin levels are a measure of circulating iron, ferritin levels are a measure of iron stores in the body, which is why they are differentiated in the above statement.
Interestingly, “late” cord clamping is classified as waiting for an interval of between one and three minutes after birth. The WHO review noted a greater benefit with a three minute delay than with one minute. Three minutes is such a short period of time, but it has a significant effect on infant haemoglobin and iron stores which is evident for months afterwards. If we are patient during the three minute period after a baby is born, and don’t clamp or cut the cord prematurely, a physiological shift occurs which effectively ensures the infant has the appropriate amount of blood volume before the job of the placenta is finished, and the cord is no longer needed.
As for risks, the WHO review noted that there are no higher incidences of newborn jaundice with delayed cord clamping, but there was a higher incidence of those babies who were jaundiced needing phototherapy. Otherwise, it appears that delayed cord clamping poses no other risk to baby or mother. Clearly, it is of benefit to delay cord clamping.
Recent changes in practice regarding cord clamping have included waiting until the cord stops pulsating before clamping; this reflects a physiological approach which takes into account the natural variation of human biology. However, some care providers will wait three minutes rather than follow the cord pulsations. Some care providers have not changed their practices with regards to cord clamping despite evidence that suggests the benefit of waiting. It would be wise to discuss cord clamping with your care provider if you wish to delay it, so that your preference can be followed.
There are a number of approaches to the umbilical cord, and we will be examining these in the coming week, including cord blood collection and storage, and lotus birth, where the cord remains intact and the placenta attached to it until the cord naturally detaches from the umbilicus. Stay tuned for more on the miraculous umbilical cord~baby’s lifeline!
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I'm really looking forward to reading the rest of the posts you have on this topic! Out of all the arguably wacky things on my birth plan the last time around, the only thing the OB I shared it with while pregnant hesitated on was the request for delayed cord clamping. He had never heard of the idea! He was concerned that it would also delay expulsion of the placenta, but fortunately listened to my reasons and agreed to wait. Hopefully obstetrics catches up soon!
I was too out of it to note how long they actually waited, but anemic me produced a child with perfect iron levels at age 9 months, despite a vegetarian diet and having never been supplemented. Woohoo!