Delayed Cord Clamping May Benefit At-Risk Infants

Jim Kling

October 07, 2010

October 7, 2010 (San Francisco, California) — Delayed cord clamping (DCC) shows benefits in extremely low-birth-weight infants, including a reduction in intraventricular hemorrhage. These results, from a recent trial, were presented here at the American Academy of Pediatrics 2010 National Conference and Exhibition.

Physicians routinely perform immediate umbilical cord clamping (ICC) after infant delivery, but there is evidence that DCC may have health benefits for neonates. The mechanism behind these effects is unknown, but cord blood contains progenitor cells that may account for the benefits through their developmental and reparative properties.

The researchers hypothesized that DCC may be useful for infants born before 28 weeks' gestational age (GA) and are at the highest risk for intraventricular hemorrhage (IVH). "We wanted to see if there's an application of [DCC], which is already proven in an older population, to the most premature infants," Carl Backes, MD, a neonatologist at Nationwide Children's Hospital in Columbus, Ohio, who presented the research, told Medscape Medical News.

The team conducted a randomized controlled clinical trial, enrolling pregnant women at 23 to 27.6 weeks' GA who were assigned to either ICC or DCC. In the ICC group, the umbilical cord was clamped within 10 seconds of birth. In the DCC group, the cord was clamped 45 seconds after birth. The researchers collected neonatal blood at admission, after 48 hours, and after 30 days and examined it for progenitor cells, including AC133+/CD45−, CD34+/CD45−, and AC133+/CD34+/CD45− cells. Each cell was quantified as a percentage of mononuclear cells in blood. The team used cranial ultrasound to determine IVH.

There were 10 infants in each group, with no difference in maternal demographics (mother's age, race, antenatal steroids, magnesium, mode of delivery, or duration of premature rupture of membranes). Both groups were also equivalent in birth weight, gestational age, Apgar scores, initial hematocrit, and male/female ratio.

No significant difference was seen in incidence of IVH between the 2 groups (DCC, 1/10; ICC, 3/10; P = .2), Dr. Backes reported.

Infants less than 26 weeks' GA who underwent DCC had a lower incidence of IVH compared with infants of the same age who underwent ICC (DCC, 0/6; ICC, 3/5; P = .023). Infants in the DCC group had higher temperatures at admission than infants in the ICC group (97.3 vs 95.0; P = .018). At 48 hours, infants in the DCC group had an increase in the percentage total of progenitor cell types in blood samples (P = .036). There were no significant differences in progenitor cell percentages at admission and at 30 days.

"I think [DCC] can be done safely. We need to continue to discuss with our obstetrical colleagues the different interventions on both sides of the table that we can use to improve outcomes. We would also like to transition to a multicenter trial, because that's the only way we can demonstrate beneficial effects," said Dr. Backes.

"It's a very well-designed study, not only to understand the clinical effects of [DCC] but also to understand the mechanisms that might explain [them]. Both will be required to have any choice of gaining acceptance in the medical community," DeWayne Pursley, MD, MPH, chief of neonatology at Beth Israel Decaconess Medical Center and Harvard Medical School in Boston, Massachusetts, who attended the presentation, told Medscape Medical News.

The study did not receive commercial support. Dr. Backes and Dr. Pursley have disclosed no relevant financial relationships.

American Academy of Pediatrics 2010 National Conference and Exhibition: Abstract 10973. Presented October 2, 2010.