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What is delayed cord clamping? (VIDEO)
The phrase "delayed cord clamping" means to wait before clamping the umbilical cord after birth.
Prior to birth, the baby relies on the umbilical cord blood for oxygen and nutrition. In the moments after birth, the baby takes its first breathe. At that moment of the first breathe, the baby's lungs call for more blood supply and some blood from the umbilical cord vein enters the baby. But at the same time, when the baby starts to breathe, the arteries that carry blood from the baby to the umbilical cord constrict. Hence the blood circuit between the baby and the placenta shuts down once the baby breathes. Some blood may continue to flow from the umbilical cord to the baby if uterine contractions put pressure on the placenta. Medical research shows that any time after the first breathe is an OK time to clamp the umbilical cord. We have another FAQ with a table of medical society recommendations for delayed cord clamping.
An important caveat is that, when a baby is born prematurely, the baby may not spontaneously breathe. In this case the baby will not spontaneously draw blood from the umbilical cord. We have a news article about cord milking as an alternative to delayed cord clamping, and whether it is safe for premature babies.
- van Rheenen, P et al. Delayed cord clamping and haemoglobin levels in infancy: a randomised controlled trial in term babies. Tropical Med. and Internal Health 2007; 12(5):603-616.
- Hooper SB, Binder-Heschl C, Polglase GR, et al. The timing of umbilical cord clamping at birth: physiological considerations. Maternal Health, Neonatology and Perinatology 2016; 2:4.
- Katheria AC, Lakshminrusimha S, Rabe H, McAdams R, Mercer JS. Placental transfusion: a review. Journal of Perinatology 2017; 37:105–111.