When doctors deliver a healthy newborn, it's common to wait about a minute to clamp and cut the umbilical cord, giving the baby the benefits of extra cord blood as it begins its life outside the womb.
The same is not true for babies born limp, with minimal breathing. The go-to plan for those babies, known as "non-vigorous" infants, has been to clamp the cord quickly and work on stabilizing them.
Now, a new study suggests there might be a different option for these high-risk newborns, one in which the doctor gives the cord a few gentle squeezes, “milking” it of its benefits for the baby by slowly pushing the blood into the baby's abdomen. That's followed by swiftly clamping the cord and then beginning resuscitation efforts.
The study, which used either option in 10 hospitals, found that non-vigorous infants who received umbilical cord milking were less likely than those getting standard care to need heart and respiratory support.
The babies who received cord milking were also less likely to have low oxygen levels in their brains, and they were more likely to have higher levels of hemoglobin, which indicates the presence of red blood cells.
“The question has always been for the babies who aren't doing well at birth, who aren't breathing or are limp or blue, is there something else we could do?” said study author Dr. Anup Katheria, a neonatologist at the Sharp Mary Birch Hospital for Women and Newborns, in San Diego.
“That's what this study aimed to look at, which was in those babies who aren't well, who can't get delayed cord clamping because they need to get resuscitated by someone like me quickly, would squeezing the cord a few times help improve their outcomes, such as being admitted to the ICU, or prevent brain injury?” Katheria added.
The study included 1,730 babies of more than 16,000 born at the 10 institutions after 35 to 42 weeks of pregnancy.
The reasons the babies would be born not vigorous can vary, including that the umbilical cord is compressed or pinched during delivery, which would decrease the amount of blood — and thus oxygen — reaching the infant. The placenta can also become detached or stop working properly.
“All of these things can, as long as you provide this additional blood towards a baby, these conditions can be at least partially reversed or partially helped,” Katheria said.
“It's important to note that this is not just blood," he explained. "Cord blood for babies is different than the blood you and I would get if we needed a blood transfusion. It's full of billions of stem cells and immune-fighting cells, everything that a newborn needs. That's not found in normal blood products when you go to the blood bank.”
In the study, at hospitals in the United States, Canada and Poland where babies had cord milking, providers milked 20 centimeters of cord for two seconds, repeating the procedure three times.
Admission to a newborn intensive care unit was not significantly different between those whose umbilical cords were immediately clamped and those with milked cords.
But there were differences in other measures: 61% in the milking group required heart and respiratory support, compared to 71% of the clamping group. Meanwhile, low blood oxygen levels in the brain were seen in 1.5% of the milking group compared to 3% of the clamping group.
Non-vigorous infants are at risk for a variety of health conditions, including low oxygen levels in the brain, cerebral palsy and stroke.
Katheria said he hopes the study will lead the governing bodies who craft guidelines for obstetricians to evaluate the evidence.
“I can't say what everybody should start doing for the recommendation, but we do feel like it provides good evidence that this is a safe method that has benefits,” Katheria said.
The researchers plan to continue following the babies until they are 2 years of age.
The findings were published online recently in the American Journal of Obstetrics and Gynecology.
Dr. Maria Mascola, a maternal-fetal medicine specialist at the Marshfield Clinic Health System in Wisconsin and lead author of the clinical guidance on cord-cutting for the American College of Obstetricians and Gynecologists, said the study addressed an important area of care for newborns.
“This clinical scenario poses a real challenge for those taking care of the mother/baby: Should they implement delayed cord-cutting with all its known benefits or should they immediately begin resuscitation?” Mascola said. “Umbilical cord milking offers a third strategy that has not been previously well-studied in this particular group of newborns.”
Mascola noted that the study found important benefits, while not finding previously identified possible problems associated with umbilical cord milking, including a brain bleed or too many red blood cells.
“One of the challenges of umbilical cord milking is standardizing it: There are many ways to do it, and it is key to make sure that when it is carried out, it is done so in a specific way that is shown to be safe in studies such as this one,” Mascola said.
The March of Dimes has information about saving umbilical cord blood.
SOURCES: Anup Katheria, MD, neonatologist and director, Neonatal Research Institute, Sharp Mary Birch Hospital for Women and Newborns, San Diego; Maria Mascola, MD, MPH, maternal-fetal medicine specialist, Marshfield Clinic Health System, Marshfield, Wis.; American Journal of Obstetrics and Gynecology, Aug. 12, 2022, online