A technique to increase the flow of blood from the umbilical cord into the infant's circulatory system improves blood pressure and red blood cell levels in preterm babies delivered by Cesarean section, scientists, including one of Indian-origin, have found.
The technique, known as cord milking, consists of encircling the cord with thumb and forefingers, gently squeezing, and slowly pushing the blood through the cord to the infant's abdomen.
For infants delivered by Cesarean, cord milking appears to offer benefits over the standard practice of waiting 45 to 60 seconds before clamping and cutting the umbilical cord.
These benefits, which include greater blood flow to and from the heart, higher red blood cell level, and higher blood pressure, were seen only in the infants delivered by Cesarean.
Among a smaller number of vaginal births, the researchers found no difference in blood volume between infants undergoing cord milking and those undergoing delayed cord clamping.
Delaying umbilical cord clamping by 30 to 60 seconds is thought to allow sufficient time for blood from the umbilical cord to fill the blood vessels in the infant's lungs.
Among preterm infants, the delay is believed to protect from intraventricular hemorrhage, or bleeding in the ventricles - the cavities inside the brain.
The hemorrhage is thought to result from low blood pressure, brought on by having too little blood in the circulatory system.
The study's first author Dr Anup C Katheria, from the Neonatal Research Institute at the Sharp Mary Birch Hospital for Women and Newborns in San Diego, noted that some studies failed to find a reduction in intraventricular hemorrhage from delayed cord clamping.
The scientists theorised that the use of an anesthetic in Cesarean delivery reduces uterine contractions, and hinders the exodus of blood from the umbilical cord.
Cord milking, they reasoned, might compensate for diminished blood flow through the umbilical cord and increase the amount of blood available to the infant.
The researchers enrolled 197 infants in their study. Mothers went into labor at or before the 32nd week of pregnancy. Of these, 154 were delivered by Cesarean, with 75 assigned at random to the umbilical cord milking group and 79 assigned to the delayed clamping group.
The 43 infants delivered vaginally also were assigned at random to either delayed clamping or umbilical cord milking.
Of the infants undergoing Cesarean deliveries, those in the cord milking group had higher blood flow in the superior vena cava, the large vein carrying blood from the brain to the heart, and a higher output of blood from the right ventricle.
Infants in the cord milking group also had higher blood pressure and higher levels of hemoglobin.
The study was published in the journal Pediatrics.
