Study suggests umbilical cord milking is safe for infants over 28 weeks: Previous study halted due to brain bleeding
A 2019 umbilical cord milking study was halted due to the high risk of brain bleeding associated with cord milking in preterm infants born under 19 weeks. A new study suggests that umbilical cord milking is safe for infants born after 28 weeks.
Dr. Anup Katheria, a researcher and neonatal physician based in San Diego, led both National Institute of Health studies.
Umbilical cord milking is the process of gently squeezing the umbilical cord between the index and forefinger, pushing blood into the abdomen of preterm infants. This is done to increase blood pressure, reduce the risk of anemia, increase urine output, lower the risk of chronic lung disease, lower the risk of life-threatening illnesses and reduce the risk of transfusions.
When infants are born, practitioners choose between immediately clamping the umbilical cord, delaying umbilical cord clamping or milking the umbilical cord.
Immediate cord clamping can be associated with hypoxia, infections, delayed motor development and anemia. Practitioners may choose to perform immediate cord clamping in preterm infants if there is no other option and they must immediately resuscitate the infant.
Delayed cord clamping is the act of waiting 30-60 seconds to clamp the umbilical cord. This allows the blood to flow freely from the placenta and can decrease the risk of severe complications.
“We do not study immediate cord clamping because we don’t think it’s ethical,” Dr. Katheria said. “My fear was that if you’re too scared of milking, then you are not going to get these babies any blood. We need to find an alternative for when delayed cord clamping is not possible.”
According to Dr. Anup Katheria’s review, umbilical cord milking provides a placental transfusion without postponing resuscitation and can be completed as quickly as immediate cord clamping. Infants receive more blood from the placenta when cord milking is performed over delayed clamping when babies are born via cesarean section.
Umbilical cord clamping should be used over delayed cord clamping when delayed cord clamping is not possible or when they are born via c-section. According to the World Health Organization, most preterm infants are born by c-section.
“When a baby is born vaginally, one of the big differences between a baby born by c-section is that the uterus helps squeeze blood from the placenta,” Dr. Katheria said. “It’s not that umbilical cord clamping would not work for babies born vaginally, you just don’t need it to work as well.”
Dr. Anup Katheria’s 2019 umbilical cord milking study was halted because cord milking was deemed linked to brain bleeding in infants under 19 weeks. In order to continue with the study, infants born from 20-32 weeks were enrolled in the new study.
The new study found that umbilical cord milking was safe and effective in infants born over 28 weeks.
Dr. Katheris found no harmful complications due to cord milking in the new group of newborns born 20-32 weeks. Researchers are following up with participants at the two year mark to review any long-term effects of cord milking.
“Next year or so, we should be finished seeing all of these children at two years of age and done developmental testing to make sure that there are no longer term complications,” Dr. Katheria said. “It is unlikely that if you don’t see any problems at two, they are unlikely to have the inability to walk or talk. It’s a good, early measure.”
Dr. Katheria cited Dr. Heike Rabe’s early work as a major influence on the work performed in this study. Dr. Rabe is a researcher and Professor of Perinatal Medicine in Brighton, UK.
“I think [umbilical cord milking] is an important back-up method of optimal cord management in a situation where delayed cord clamping is not possible,” Dr. Rabe said. “For example, a severe hemorrhage of the mother or uterine rupture.”
Dr. Rabe added that the World Health Organization said, “immediate cord clamping is contra-indicated.”
“To me, that is a very strong statement which they do not use very often,” Dr. Rabe said.
This means that immediate cord clamping is not advised as a course of treatment for infants, further proving the findings of Dr. Katheria’s study.
Dr. Rabe and Dr. Katheria each mentioned practitioners being hesitant to perform cord milking. Both researchers highlighted the need for more training and education surrounding the topic.
“The main thing to really understand about this topic is that this is not a procedure that most neonatologists are very comfortable with,” Dr. Katheria said. “I am studying something that people prefer not to do.”