A new study by the National Institutes of Health has revealed one of those oddities that make medicine so interesting: Babies today are taking a much longer time being born than they were half a century ago. To be specific, the average first-time mom pushes through to the finish line in 6.6 hours, versus just four hours in the 1960s. (Labor’s longer for repeat moms as well.) And what seems like just a weird “How about that?” statistic actually has major implications for maternal health and medical costs.
The lengthening of labor would seem to belie the rise in the use of oxytocin to speed it up; administration of the hormone has climbed from 12 percent of ’60s deliveries to 31 percent today. The rate of cesarean section is also four times higher today. And researchers say that may be because obstetricians are using outdated standards for how long labor should last; if you expect a baby to be born in four hours, you’re more likely to intervene when it isn’t, calling for a cesarean even if it might not be medically necessary. The national cesarean rate today is 32 percent; a cesarean costs almost $17,000, versus $9,400 for a vaginal delivery.
The researchers posited a number of factors that may have stretched out labor. The average first-time mom today is four years older than she was in the ’60s, and also weighs more. Maternal age and obesity are both risk factors in pregnancy, perhaps making doctors more inclined to intervene by administering epidurial anesthesia, which prolongs labor by between 40 and 90 minutes, or to induce labor; only one in three women in the study period of 2002 to 2008 went into labor spontaneously. The study’s authors suggest a reassessment of what constitutes a “normal” labor, and reworking the milestones laid down in the 1950s to reflect reality today.