Photo courtesy of Meutia
Chaerani & Indradi Soemardjan
Umbilical cord milking may be more beneficial than delayed cord clamping for preterm infants delivered by Cesarean section, according to new research.
The study showed that cord milking produced greater blood circulation, higher hemoglobin levels, and higher blood pressure, but only in preterm infants delivered by Cesarean.
For preterm infants delivered vaginally, there was no significant difference between the milking and delayed clamping groups.
Anup C. Katheria, MD, of the Neonatal Research Institute at the Sharp Mary Birch Hospital in San Diego, California, and his colleagues reported these findings in Pediatrics.
The researchers noted that, 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.
This is thought to allow sufficient time for blood from the umbilical cord to fill the blood vessels in the infant’s lungs and to protect infants from intraventricular hemorrhage. However, some previous studies failed to find a reduction in intraventricular hemorrhage from delayed cord clamping among preterm infants delivered by Cesarean.
Dr Katheria and his colleagues theorized that the use of an anesthetic in Cesarean delivery reduces uterine contractions and therefore hinders the exodus of blood from the umbilical cord.
They reasoned that cord milking—encircling the cord with thumb and forefingers, gently squeezing, and slowly pushing the blood through the cord to the infant’s abdomen—might compensate for diminished blood flow through the umbilical cord and increase the amount of blood available to the infant.
To test this theory, the researchers enrolled 197 infants in a prospective study. Mothers went into labor at or before the 32nd week of pregnancy.
Of the 154 infants delivered by Cesarean, 75 were randomized to the umbilical cord milking (UCM) group and 79 to the delayed cord clamping (DCC) group.
Infants in the UCM group had significantly higher blood flow in the superior vena cava than those in the DCC group—93 ± 24 mL/kg per min vs 81 ± 29 mL/kg per min (P<0.05)—and a significantly higher output of blood from the right ventricle—261 ± 80 mL/kg per min vs 216 ±73 mL/kg per min (P<0.001).
These measures, taken together, are an indication of blood circulation in the brain and body.
Infants in the UCM group had significantly higher hemoglobin levels at birth than infants in the DCC group—16.3 ± 2.4 g/dL vs 15.6 ± 2.2 g/dL (P<0.05). And mean arterial pressure in the first 15 hours of life was significantly higher in the UCM group than the DCC group (P=0.02).
Among the 43 infants who were delivered vaginally, the researchers found no significant differences in outcomes between infants randomized to UCM or DCC.
