A technique that increases the flow of blood from the umbilical cord into an infant's circulatory system could improve blood pressure and red blood cell levels in preterm infants who are delivered via cesarean section.
The method, known as "cord milking," consists of gently squeezing the umbilical cord and pushing blood into the infant's abdomen, the National Institutes of Health reported. This method proved to come with a number of benefits when compared with the standard practice of waiting 45 to 60 seconds before clamping the umbilical cord in preterm infants delivered by a C-section.
"The study results are very encouraging," said Tonse Raju, M.D., chief of NICHD's Pregnancy and Perinatology Branch. "The findings need to be confirmed in a larger number of births, but at this point, it appears that umbilical cord milking may prove to be of great benefit to preterm infants delivered via cesarean."
In 2012, the American College of Obstetricians and Gynecologists recommended a 30 to 60-second delay before clamping the umbilical cord in all preterm deliveries, but have yet to make a recommendation as to when to clamp the cord in term births. Delayed umbilical cord clamping is believed to allow time for blood to fill the infant's vessels. In preterm infants, delayed cord clamping can also prevent bleeding in the ventricles of the brain.
The researchers noted some studies have not found a link between delayed cord clamping and risk of intraventricular hemorrhage preterm infants delivered by C-section. The use of anesthetic in C-section delivery could reduce uterine contraction, which in turn would reduce blood flow through the umbilical cord. Cord milking could help solve this problem and compensate for the reduced blood flow caused by the anesthetic.
To make their findings, the researchers looked at 197 infants whose mothers went into labor at or before week 32 of their pregnancy. The infants were randomly assigned to either receive umbilical cord milking or solely delayed cord clamping; out of the sample 43 infants were delivered vaginally and the rest were delivered via C-section. Out of the infants who underwent cesarean deliveries, those who received cord milking had a higher blood flow rate in the large vein that connects the brain and heart. They also had a higher output of blood in the right ventricle as well as higher blood pressure and levels of hemoglobin. Among the infants who were delivered vaginally, the researchers did not observe a difference between those that received cord milking or delayed cord clamping alone.
The findings were published in a recent edition of the journal Pediatrics.
