Research suggests factors other than gestational age may affect survival of premature babies.

On the front page of its Personal Journal section, the Wall Street Journal (4/17, D1, Winstein) reports that a study published in this week's New England Journal of Medicine, and a website created by the National Institutes of Health, "aim to help parents of extremely premature babies calculate their newborn's chances of survival." During the study, conducted by researchers at the University of Texas Medical School, "4,450 babies born after 22 to 25 weeks' gestation" were tracked. The investigators found that, beyond gestation period, "other factors were at least as important to the baby's survival. Girls survived much more often than boys -- so much, that being a girl was equivalent to an extra week in the womb." Moreover, "Increased birth weight also improved the chances of survival."

According to the New York Times (4/17, A23, Grady), being "singletons rather than twins or multiples, [and whether] their mothers had been given steroids before birth to help the fetal lungs to mature," also contributed to the babies' survival. According to the researchers, "[a]ny of those factors was about as good as being a week older, which makes an enormous difference in development from 22 to 25 weeks' pregnancy." The Times notes that "[o]utcomes are nearly impossible to predict at birth" for premature babies. "Although some extremely premature infants do well, many die, sometimes after weeks or months of painful invasive procedures in the intensive care unit." Those that survive "often suffer brain damage, behavior problems, vision and hearing loss, and other disabilities." Because of these factors, "[d]octors and parents struggle to decide when aggressive treatment seems reasonable."

Researchers and the National Institutes of Health now hope the study can "provide the parents and doctors of very premature newborns with a better way to assess children's chances of survival or disability," USA Today (4/17, 8D, Szabo) reports. By considering the four factors identified by the study in addition to gestational age, doctors can now "predict survival with a three percent margin of error." In contrast, "[g]estational age has a 12 percent margin of error." For example, the "study notes that a girl born at 24 to 25 weeks at 1.7 pounds who was treated with steroids has a 33 percent chance of dying or being profoundly impaired," while the "risk rises to 87 percent for a twin boy of the same age who weighs 1.2 pounds and who didn't get steroids."

Reuters (4/17, Emery) notes that the National Institute of Child Health and Human Development, which "funded the study," includes a calculator on its website. The calculator is "designed to guide doctors and families" make better-informed decisions "about possible infant outcomes based on standardized assessments."

The AP (4/17, Stobbe) reports that, after seeing the results, "[s]ome doctors said they were startled to see that certain factors equated to an extra week in the womb." In the results, researchers also suggest "that in cases where boys and girls had equal chances of survival, girls were less likely than boys to receive intensive care." While "[i]t's not clear why," it may be because "heavier babies tend to get intensive care more often, and boys tend to be heavier." Medscape (4/16, Barclay) and WebMD (4/16, Hitti) also reported the story.