Cutting umbilical cordThe practice of delayed cord clamping is a topic of much debate in maternity centers around the world. Traditionally, the umbilical cord is cut within seconds of birth. Doing so stops the flow of blood from mother to child but advocates of delayed clamping say the baby can benefit from a little extra blood flow at this critical moment in time.

Why Wait?

Delayed cord clamping, usually three minutes or longer after delivery, has been found to produce positive effects in the moments after childbirth by increasing the flow of blood from the mother through the nutrient-rich placenta and into the newborn’s body. This blood is rich in iron, a nutritional mineral vital for brain development. The added iron-rich blood helps bring the baby’s blood supply up to a healthy volume and allows the lungs to quickly adjust to transferring oxygen from the air into the bloodstream. Between 4 and 6 months of age, babies who had delayed clamping have been found to experience less anemia than those clamped traditionally.

Preemies and Delayed Clamping

A substantial body of research has been conducted on delayed cord clamping for babies born prematurely. Benefits that begin at birth are seen even days after delivery. Preemies who have their cord clamping delayed by a few minutes have a tendency to have healthier blood pressure days after birth. They require fewer blood transfusions, experience less bleeding into the brain, and enjoy a reduced risk of necrotizing enterocolitis, a dangerous bowel injury that can be fatal.

Long-Term Effects of Delayed Clamping

Little study of long-term effects of delayed cord clamping has been done, however, but a recent study from Sweden does take a longer view. Dr. Ola Andersson, of the Department of Women’s and Children’s Health at Uppsala University, and her research team explored the long-term effect of delayed cord clamping and neurodevelopment in children 4 years old.

Anderson’s research team compared neurodevelopmental outcomes in 4-year-old children who had been born in the same county hospital in Sweden from 2008 to 2010. The study began with 382 infants born full term following low-risk pregnancies. Some of the children had their umbilical cords cut in less than ten seconds after delivery and others were clamped three minutes or more after delivery.

By the time these babies turned 4 years old, 263 of them were still in the study. Each of these children was subjected to a number of age-appropriate tests for personal-social skill development, fine motor skills, processing speed, and other measures of neurological development. All tests were assessed by a psychologist who did not know which tests belonged to children in either the delayed clamping group or the traditional group.

Boys Benefit the Most

The test scores indicated only a modest improvement in fine-motor and social skills in the group getting delayed clamping. When the children’s test scores were divided by gender, a different picture emerged. The boys in the delayed clamping group scored significantly higher in these neurodevelopmental tasks than the other children. It is speculated that girls’ exposure to high levels of estrogen in the womb protects them from neurodevelopmental issues before birth.

Critics of the study express concern that the study was conducted on an affluent population where anemia during pregnancy is rare. Further study, conducted in poorly developed nations where anemia is common, might produce a better indicator of long-term effects of delayed clamping.


  1. Andersson, Ola, et al. "Effect of Delayed Cord Clamping on Neurodevelopment at 4 Years of Age: A Randomized Clinical Trial." JAMA Pediatrics (2015). The JAMA Network. Web. 9 June 2015.
  2. Haelle, Tara. "Delayed Umbilical Cord Clamping May Benefit Children Years Later." NPR / Shots. npr, 26 May 2015. Web. 9 June 2015.