Progesterone Therapy and Preterm Birth
Two major studies can help doctors better identify pregnant women at risk for preterm delivery who can benefit from progesterone treatment.
In one large multi-center trial led by Eduardo B. Fonseca, M.D., women with short cervix (most of whom had no prior history of preterm birth) who received progesterone suppository treatment between 24 and 34 weeks gestation had a greatly reduced rate of preterm birth.
Another large multi-center trial led by Dwight J. Rouse, M.D., found that weekly injections of 17P (17 alpha-hydroxyprogesterone caproate, a derivative of progesterone) between 16 and 35 weeks gestation did not reduce the rate of preterm birth among women carrying twins.
"Premature birth is a growing problem in the United States and a leading killer of newborns," said Michael Katz, senior vice president for Research and Global Programs of the March of Dimes. "With this new information, physicians will have a better idea of how to identify those women who are most likely to benefit from progesterone treatment from those who are not."
Dr. Katz noted that pathways to preterm birth may differ substantially between singleton and twin gestations. For example, progesterone may be more effective against some pathway that does not involve the uterine over- distention seen in twin pregnancy.
"We need more research into the underlying causes of prematurity to help women with other risk factors," Dr. Katz said.
In previous studies the benefit of progesterone was seen in women with singleton pregnancies and a documented history of a previous spontaneous preterm birth. These study results led to a Committee Opinion issued by the American College of Obstetricians and Gynecologists on the use of progesterone therapy, published in the October 2003 issue of Obstetrics & Gynecology.
The March of Dimes works to improve the health of babies by preventing birth defects, premature birth and infant mortality. For more information, visit marchofdimes.com or nacersano.org for Spanish language information.