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Certain Drug Therapies Are Effective in Prolonging Pregnancies of Women in Preterm Labor

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Press Release Date: December 18, 2000

A new evidence report from the Agency for Healthcare Research and Quality (AHRQ) found that certain drug therapies and diagnostic tools can have a positive outcome on the treatment of preterm labor. The Research Triangle Institute-University of North Carolina Evidence-based Practice Center found evidence proving that the use of tocolytics, drugs that stop uterine contractions, during an episode of preterm labor is an effective means of extending the length of the pregnancy. In contrast, continued use of these medications, after contractions have subsided, offers no apparent further benefit.

Early detection and effective management of preterm labor are important women's health concerns because preterm labor is a common precursor to preterm birth (prior to 37 weeks' gestation). Preterm births represent 11 percent of all live births, are a leading cause of infant morbidity and mortality, and account for one-third of all health care spending on infants.

Hidden infections of the upper genital tract are believed to be a significant risk factor for preterm labor. The AHRQ evidence report also found that antibiotics prolong the length of the pregnancy and the infant's gestational age at birth, suggesting that hidden infections do play a role in preterm labor but that their potentially harmful impact can be moderated.

The goals of these drug therapy treatments are to prolong pregnancy to term or long enough for substantial increases in gestational age and infant birth weight. At a minimum, the goal is to prolong gestation long enough for clinicians to administer an effective regimen of corticosteroids to enhance fetal lung development.

The report also found that two diagnostic tools, fetal fibronectin tests and endovaginal ultrasound, are effective in predicting which women with symptoms of preterm labor are at low risk of preterm birth. These tests can usefully supplement clinical judgment, offering valuable information that helps avoid unnecessary treatments.

In addition, after controlling for whether the women received nursing support, the use of home uterine activity monitoring for women in preterm labor was not found to have an effect on the infant's gestational age at birth or birth weight.

The summary of the evidence report, Management of Preterm Labor, is available online at Printed copies of the summary are available from the AHRQ Publications Clearinghouse by writing to P.O. Box 8547, Silver Spring, MD 20907, or by calling (800) 358-9295 within the United States or (703) 437-2078 from outside the country. Copies of the full report are expected to be available from the clearinghouse in early 2001.

For more information, please contact AHRQ Public Affairs, (301) 427-1364.

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