Pregnancy may be a blessed event, but it's also a time of hormonal chaos, swirling emotions, and 30 pounds of extra weight. Despite all this stress, however, mothers-to-be are far less likely to commit suicide than other women their age, reports Peter Marzuk, M.D., a psychiatrist at Cornell University Medical College. Of the 315 New York City women who took their own lives between 1990 and 1993, only six were carrying a child--about 70 percent fewer than you'd expect given the city's pregnancy and suicide demographics, according to Marzuk.
While there are, no doubt, psychological factors that help explain the low suicide rate among pregnant women, Marzuk believes that the brain chemical serotonin also plays a key role. Low serotonin levels have been linked to higher risks of depression and impulsive behavior. But during pregnancy a fetus begins churning out its own serotonin supply--some of which finds its way to the mother's brain. The upshot: Even if a pregnant woman is more depressed than her non-pregnant peers, this serotonin surge may make her less likely to act on any suicidal impulses, Marzuk suggests in the American Journal of Psychiatry. So whether by coincidence or design, the neurochemical boost helps a fetus ensure its own survival.