‘Milking’ umbilical cords may help some sickly newborns

Giving birth to a child who is unresponsive or struggling to breathe is a harrowing experience. The medical team must quickly cut the umbilical cord and then rush the baby to aid. But taking a few seconds to squeeze blood from the cord into an infant’s abdomen before cutting the cord could help with the infant’s recovery, two recent studies suggest.

The practice, known as umbilical cord milking, is relatively unknown and not without some controversy. But if its promise holds up, it may help protect some of the most at-risk newborns, researchers say.

During fetal development, the umbilical cord brings nutrients from the placenta, which also serves as a reservoir for blood, iron and stem cells (SN: 4/4/18). At birth, the infant is still connected to this reservoir, and the standard recommendation is to wait at least 30 seconds to a minute before clipping that connection, allowing the baby to take in more of those essential nutrients.

Some studies suggest that for healthy babies, delayed cord clamping can improve some aspects of health, such as iron levels or fine motor skills, for months or even years.

For babies born with urgent health problems, however, there’s no time to wait. In these cases, quickly milking the cord might provide similar benefits as delayed cord clamping. But the jury is still out on if or when to use the technique. The American College of Obstetricians and Gynecologists, for example, said that there is “insufficient evidence to support or refute umbilical cord milking” in its 2020 guidelines, which the group reaffirmed earlier this year.

In one of the new studies, researchers randomly assigned 10 medical centers in three countries to one of two groups. If an infant was born limp, with difficulty breathing or bluish skin, the cord was immediately clamped and cut in one group. In the other, the umbilical cord was milked four times before being cut. The hospitals then switched practices halfway through the study.

After analyzing outcomes for over 1,700 infants, researchers found that babies who had had their umbilical cords milked were less likely to need extra oxygen or other breathing assistance. The newborns were also less likely to suffer from a brain injury called hypoxic encephalopathy that’s caused by a lack of oxygen to the brain before or shortly after birth, the team reported in the February American Journal of Obstetrics and Gynecology.

In a follow-up analysis of blood flow in over 200 of the infants, published in the June Journal of Pediatrics, the researchers found that these improved outcomes were probably due in part to increased blood volume and blood flow to the heart, lungs and brain in the infants who received the cord milking. These newborns also had slightly higher levels of hemoglobin, the protein which carries oxygen in human blood, than babies whose cords were quickly cut.

“We saw dramatic differences in the babies that have this extra blood,” says Anup Katheria, a neonatologist at Sharp Mary Birch Hospital for Women & Newborns in San Diego.

The new research adds key evidence in favor of umbilical cord milking, says Heike Rabe, a neonatologist at Brighton and Sussex Medical School in England who has collaborated with Katheria but wasn’t involved in the two studies. The findings offer important assurance to obstetricians who might be hesitant to adopt the practice, she says. “It should really be getting into standard of care.”

The intervention is quick, simple and does not require equipment, meaning it might be readily adopted in places with limited medical resources.

But the practice could harm some infants’ health. Another study lead by Katheria ended early in 2019 after it found that umbilical cord milking increased the likelihood of brain bleeding in very preterm infants, those born at less than 32 weeks of pregnancy.

Based on the recent studies, umbilical cord milking “shows promise” in infants born in poor health at or near term, says Sarah McDonald, a maternal-fetal medicine specialist at McMaster University in Hamilton, Canada, who wasn’t involved in the studies. But more research is needed before the practice is recommended for use, even in emergency situations. And for most infants, she and Katheria agree, delayed cord clamping will likely remain the best course of action.