(AP) CHICAGO
A U.S. study linking a shortened cervix early in pregnancy with premature birth could help pinpoint which women are most at risk and potentially help doctors intervene earlier, researchers say.
The study of 183 women who'd had previous premature births found that a shortened cervix at 16 to 18 weeks of pregnancy tripled the risk of prematurity.
The condition later in pregnancy has been linked to premature births, but the new study shows it may also be a problem when found much earlier.
The study, led by Dr. John Owen of the University of Alabama in Birmingham, is published in Wednesday's Journal of the American Medical Association.
The cervix is the cylindrical mouth of the uterus, separating it from the vagina. Normally about 1 1/2 inches (3.8 centimeters) long, it lengthens in pregnancy to strengthen protection of the fetus, then shortens significantly near birth as the body prepares for labor and delivery.
Women studied whose cervixes measured less than about an inch (2.5 centimeters) at 16 weeks to 18 weeks of pregnancy were three times more likely to give birth prematurely than women with normal-length cervixes.
The study is significant because premature births _ those happening before the 37th week of pregnancy _ are so common, affecting about 10 percent of all pregnancies in the United States, said Dr. Catherine Spong, chief of pregnancy and perinatology at the National Institute of Child Health and Human Development. The institute funded the study.
Infants born prematurely are at increased risk for many health problems, and while technology has allowed even extremely premature babies to survive, "over the last 20 years we really haven't done anything to prevent premature births," Spong said.
She called the study "one of the first times that we've identified something very early in pregnancy that can predict patients who will deliver" early.
Spong said, however, that more research is needed to determine if the findings apply to all pregnant women since the study only involved women who'd previously had premature births.
The study should also prompt research into whether interventions including a procedure called cerclage benefit women who have short cervixes early in pregnancy, Spong said.
Cerclage, which involves stitching the cervix closed, has not been rigorously studied, but anecdotally "there are many cases where it does help," she said.
JAMA: http://jama.ama-assn.org
