Preventing Preterm Birth
The death rate varies among different geographic areas and among various ethnic and racial groups. A common and major contributor to this relatively high infant mortality rate, however, is prematurity.
The causation of prematurity has been elusive, and therapeutic approaches have been only marginally successful. In recent years, however, a more scientific approach has been taken to understand the biology of premature labor that results in premature birth. This approach has been informing our understanding of this condition.
The National Institute of Child Health and Human Development (NICHD) has made prematurity a major part of its portfolio. The institute has a branch, in fact, whose research is dedicated to this significant obstetric problem. Many years ago, the NICHD also launched the Maternal-Fetal Medicine Units (MFMU) Network, which is a national collaborative that attempts to study difficult problems in obstetrics and tries to propose scientific solutions.
Most recently, the network engaged in a study in which it attempted to reexamine a preventive approach using hormone therapy. The network employed a randomized clinical trial methodology.
In this month's Master Class, I've invited Dr. Jay Iams, a professor of obstetrics and maternal-fetal medicine at Ohio State University, Columbus, and a member of the NICHD's MFMU Network, to address the issue of hormone prophylaxis for women who have already had one preterm birth. He will update us on the network's trial and other related research, and provide us with recommendations for applying these findings to current practice.
Take Home Points For Prevention
▸ When caring for a woman with a prior preterm birth, take a thorough history of the entire pregnancy, and look for events that might have contributed. Think like an internist who is taking care of someone with a previous heart attack: Are these risks still present? Can they be eliminated or reduced?
▸ Estimate each woman's individual risk of recurrent preterm birth, taking into account the gestational age at the time of the previous preterm birth, her racial/ethnic background, and the number of prior preterm births.
▸ Consider and discuss supplemental progesterone prophylaxis with women who have had a prior spontaneous preterm birth, especially women who have had a prior early (before 32 weeks) preterm birth, or more than one prior preterm birth. Think of spontaneous preterm birth as one that did not follow a specific indication for delivery, such as fetal distress, preeclampsia, or bleeding due to placenta previa. Spontaneous preterm births are those between 17 and 36 weeks that followed premature cervical dilation and effacement with or without contractions, or preterm premature rupture of membranes.
▸ Don't use progesterone prophylaxis in women with multiple gestation.
▸ Don't use progesterone prophylaxis in women with preterm labor in the current pregnancy, or as a tocolytic.
