"Prematurity is a serious problem that affects one in eight babies in the US, and 17P offers promise in an area where there have been few successes."

Researchers from the March of Dimes, the Centers for Disease Control and Prevention, the National Institute of Child Health and Human Development (NICHD), Albert Einstein College of Medicine, Maimonides Medical Center in New York, and the New Jersey and Missouri State Departments of Health participated in the analyses.

'Very Significant' Outcome Possible

The hormone derivative is known as "17P," short for "17 alpha-hydroxyprogesterone caproate."

"Two percent would be a modest reduction in the preterm birth rate, but preventing 10,000 premature births would be very significant," said Dr. Petrini. "Prematurity is a serious problem that affects one in eight babies in the US, and 17P offers promise in an area where there have been few successes. In addition, we need more research into the underlying causes of prematurity to help women with other risk factors."

Assumptions used to estimate the impact of 17P on recurrent preterm birth were based on criteria from the promising findings of the clinical trial reported by Paul J. Meis, M.D., et al., for the NICHD Maternal-Fetal Medicine Units (MFMU) Network in The New England Journal of Medicine on June 12, 2003.

These study results led to the 2003 Committee Opinion issued by the American College of Obstetricians and Gynecologists, published in the October 2003 issue of Obstetrics & Gynecology.

Premature Birth a Growing Problem in US

In the NICHD MFMU study, the use of 17P was restricted to women with singleton pregnancies and a documented history of a previous spontaneous preterm birth, who initiated prenatal care between 16 and 20 weeks gestation. When this protocol was followed, the risk of preterm birth to these eligible women was reduced by about one-third.

The authors of today's paper estimated that in 2002, about 30,000 recurrent preterm births occurred to women who were eligible for 17P, based on a spontaneous preterm birth recurrence rate of about 22 percent.

The ACOG Committee Opinion urges more research on the role of preventing preterm birth and reminds physicians that until new results are available, they should restrict the use of 17P to pregnant women with a history of spontaneous preterm birth, singleton gestation, who start prenatal care between 16-20 weeks of pregnancy.

Premature birth is a common, serious and growing problem in the United States, the March of Dimes says. The rate of premature birth in the United States has risen 29 percent since 1981, with more than 470,000 babies born prematurely each year.