Delayed cord clamping gives preemies oxygen boost

Holding a newborn below the placenta and delaying clamping of the umbilical cord for up to 90 seconds boosts brain tissue oxygen levels in the first 24 hours after birth, neonatologists from Switzerland have found.

This technique, which doctors call "placentofetal transfusion," has been shown to reduce the need for blood transfusion and improve blood-related stability in preterm babies, note Dr. Oskar Baenziger and colleagues in the journal Pediatrics.

Increased blood volume may have profound implications on blood flow in the brain and oxygen delivery to the brain, which is of particular interest, they say, because neonatal brain injuries are "the most important sequelae of premature birth."

Baenziger's team randomly assigned 39 preemies born at 24 to 32 weeks' gestation at the University Hospital Zurich to an experimental group and 24 to the control group.

Infants in the experimental group were placed 15 cm below the placenta in cesarean-section deliveries, and as low as possible for vaginal deliveries, and the umbilical cord clamping was delayed 60 to 90 seconds. In the control group, the cord was clamped in less than 20 seconds.

At 4, 24, and 72 hours, hematocrit (the volume of red blood cells) was higher in the experimental group (55 percent versus 49 percent). At 4 hours, infants in the experimental group exhibited higher artery blood pressures and a trend toward higher levels of oxygen-loaded hemoglobin. In these same newborns, regional oxygen tissue levels were higher at 4 and 24 hours.

The investigators estimate that higher brain oxygen levels were higher at all three time points in the experimental group relative to the control group, potentially reducing the risk of adverse outcomes related to low oxygen levels in the brain.

SOURCE: Pediatrics, March 2007.

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