A Crash Course in Delayed Umbilical Cord Clamping

From the beginning of humanity until quite recently, little forethought was given to the afterbirth. Umbilical cords were tied off and placentas were discarded or used in other ways (like fertilizing a tree) during birth celebrations.

Today, most guidelines recommend delayed umbilical cord clamping, the practice of waiting to clamp the umbilical cord to allow extra blood from the placenta to flow back to the baby for about 60 seconds.

If you are an expecting parent and considering delayed cord clamping for your birth plan, read on! In the end, if you decide to not care about any of this, your birth will still be an amazing and exciting experience. Because, really, it’s all about meeting the baby.

What is delayed cord clamping, exactly?

In modern times, the baby’s umbilical cord has often been clamped immediately after birth, when the baby starts breathing and oxygenating its own blood. However, studies have shown that placental circulation through an unclamped umbilical cord can actually continue for the first few minutes of life until the placenta separates from the uterine wall. A portion of the fetal blood that was in the cord and placenta when the baby delivered gets slowly transfused back into the baby.

How much additional blood will transfuse into the baby with delayed clamping?

Studies of infants born at term estimate the transfused volume of blood from placenta to baby through the umbilical cord to be around 80 mL by one minute after birth and up to 100 mL by three minutes after birth. To put this in perspective, a term infant’s blood volume is about 85 mL/kg, which means this extra blood is roughly a third of the blood volume of an average sized term infant.

Does this extra blood benefit the baby?

The excess blood can make a significant difference in the birth transition. It supplies large quantities of iron, decreasing the risk of iron deficiency anemia in the first year of life. The additional blood exchange from the placenta also means the transfer of more maternal antibodies, protecting against infection while the newborn’s immune system begins to develop, and stem cells, which help the fetus make more blood cells.

The benefits of delayed cord clamping are even more pronounced in preterm infants, mostly because they are more prone to severe complications which might be prevented or mitigated by increased blood volume.

In term infants, the benefit is mostly increased iron levels (preventing downstream effects of iron deficiency anemia).

After multiple studies confirmed benefits in both term and preterm infants, several professional medical societies recommended routine delayed cord clamping when both the infant and mother are healthy with no need for emergency resuscitation. The American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Pediatrics (AAP) both recommend a delay of 30-60 seconds for both term and preterm infants who are well-appearing at birth.

Are there any risks to delayed cord clamping for the baby?

There are very few risks to delayed cord clamping. Term infants have a slight increased risk of jaundice requiring treatment, but the risks of mild jaundice are generally low, if a health care provider is monitoring the baby. In preterm infants with certain medical conditions, delayed cord clamping might not be recommended.

If there’s any uncertainty, your team will discuss the risks and benefits for your baby.

What about risks for the mother?

Regarding risks for the mother, although delayed cord clamping did result in some initial concern for increases in postpartum hemorrhage, this hasn’t panned out in trials. Most studies in which the cord clamping was delayed for up to 60 seconds did not show an increase in risk of bleeding for the mother.

How would I request delayed cord clamping as part of my birth plan?

The good news is that since 2017, when ACOG recommended universal delayed cord clamping at uncomplicated term and preterm births, most hospitals routinely practice delayed cord clamping.

However, it doesn’t hurt to ask. If you definitely want it, let your care team know towards the end of your pregnancy and when you arrive at the hospital or birth center where you plan to deliver. So, is 60 seconds the magic time to wait to clamp the umbilical cord? Is that when the cord stops pulsing and circulating?Sometimes it can take up to several minutes for the cord to stop pulsing and circulation from the placenta to cease. At many vaginal births, if infants are well-appearing and cry on delivery, and both the mother and infant are stable, providers will wait until the cord stops pulsing to allow full transfusion.

Most studies use the limit of 60 seconds because placental circulation continues for different lengths of time and most of the blood is transfused within the first minute. However, it’s not clear if there is significant benefit beyond a minute of delayed clamping.

That said, if you want to allow the cord to stop pulsing completely (over 60 seconds), just ask! Most providers are fine with this.

Are there times when delayed cord clamping isn’t recommended?

There are a few reasons your provider might not delay clamping beyond the recommended one minute, such as a cesarean delivery or significant maternal bleeding in a vaginal delivery.

In both of these situations, extended delay might put a mother at risk of excessive blood loss.

If your baby appears to need resuscitation immediately after delivery, delayed cord clamping might not be performed at all in order to facilitate prompt respiratory support for the infant. In these situations, your care team might “milk” the cord, i.e. push extra blood into the baby manually through the cord. Studies show this is essentially just as effective and takes only a small amount of time.

Even if delayed cord clamping doesn’t happen, all will be fine. Lots of babies born in the second half of the 20th century underwent immediate cord clamping and slept apart from their mothers in a big fluorescently-lit nursery in the hospital with other crying babies while hospital visitors stared at them through a window. One of those babies was me, and I turned out great!

Helpful Links:

ACOG Committee Opinion on Delayed Umbilical Cord Clamping: https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/01/delayed-umbilical-cord-clamping-after-birth


Delayed umbilical cord clamping after birth. Committee Opinion No. 684. American College of Obstetricians and Gynecologists. Obstet Gynecol 2017;129:e5-10.

Umbilical cord blood banking, ACOG Committee Opinion No. 771. American College of Obstetricians and Gynecologists. Obstet Gynecol 2019;133:e249-53.

Shearer WT, Lubin BH, Cairo MS, et al. AAP Section on Hematology/Oncology, AAP Section on Allergy and Immunology. Cord Blood Banking for Potential Future Transplantation. Pediatrics 2017;140(5):e20172695Kurtzberg, Joanne.

Stem Cells Transl Med. 2017 May;6(5): 1309-1311.


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This article is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. The views expressed in this article are the views of the expert and do not necessarily represent the views of Kudos.

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