Test Doesn’t Predict Preemies

A test doctors commonly rely on to predict when a woman will deliver a premature baby doesn’t seem to work after all. A study, published in this week’s New England Journal of Medicine, finds uterine monitors are not effective at predicting preterm delivery.

Doctors routinely have women use monitors at home to measure contractions. It was believed that the frequency of contractions could predict who will deliver prematurely. Preterm delivery is defined as giving birth any time before week 37 of pregnancy. According to John P. Elliott, M.D., of Good Samaritan Regional Medical Center in Phoenix, about 11 percent of all pregnancies will deliver prematurely. In the United States, that’s more than 450,000 pregnancies. Preterm delivery is the cause for more than 75 percent of deaths in newborns.

The study tracked the use of monitors on 306 women who completed the study. The researchers studied nearly 35,000 hours of recordings and concluded there is a small difference in the frequency of contractions between women who deliver preterm and those who deliver at term. “Our data indicate that ambulatory monitoring of uterine contractions does not identify women destined to have preterm delivery,” writes the research team, “and they thus explain the failure of this method to reduce the risk of preterm delivery in clinical practice.”

The study was conducted at 11 medical centers, under the guidance of the National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units.

SOURCE: New England Journal of Medicine, 2002;346:250-255