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    Early Planned C-Sections Put Baby at Risk

    Study Shows 36% of Planned C-Sections Are Performed Before 39 Weeks of Gestation
    WebMD Health News
    Reviewed by Louise Chang, MD

    Jan. 7, 2009 -- More than a third of babies born by planned, repeat C-section in the U.S. are delivered before 39 weeks gestation, and these babies are at increased risk for birth-related health problems as a result, a study shows.

    These days, nearly one in three births in the U.S. is a cesarean delivery, up from around one in five births in the mid-1990s. The increase is largely because far fewer women who have had C-sections are attempting vaginal births for subsequent pregnancies.

    National figures show that 40% of the 1.3 million cesarean deliveries performed each year in the U.S. are repeat procedures and the majority of these are planned.

    In the absence of medical need, planned, elective C-section before 39 weeks gestation is not recommended by the American College of Obstetrics and Gynecology (ACOG), unless testing shows that the baby's lungs are mature enough for delivery.

    Due Date Minus 7

    The new study shows that 36% of planned cesarean births were performed before 39 weeks.

    Researchers tracked more than 24,000 repeat C-section deliveries performed at 19 of the nation's top teaching hospitals.

    They found that:

    • Just under one in three deliveries (29.5%) was performed at 38 weeks and 6% were performed at 37 weeks.
    • Babies delivered in their 37th or 38th week had a higher incidence of birth-related adverse outcomes, including respiratory problems and sepsis (serious infection), than babies delivered in their 39th week.
    • Compared to babies delivered during their 39th week, babies born between 38 and 39 weeks gestation had up to double the risk of adverse birth-related complications; babies born between their 37th and 38th weeks had up to a fourfold increase in risk.

    The study appears in the Jan. 8 issue of the New England Journal of Medicine.

    "There appears to be a window of safety that is smaller than has generally been thought," obstetrics professor and study co-author John M. Thorp, MD, of the University of North Carolina, Chapel Hill tells WebMD. "A woman's due date minus seven days seems to be the optimal time for a planned C-section."

    Alan Tita, MD, PhD, who led the research team, tells WebMD that the number of women in the U.S. who are having early, planned C-sections may be even higher than the study suggests.

    That's because the women in the study gave birth between 1999 and 2002, and the rate of cesarean deliveries has increased since then.

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