Birth Deterrent: Stress hormone cited in early miscarriages
By Nathan Seppa
High concentrations of a stress hormone in newly pregnant women might make them more likely to have miscarriages, a new study finds.
Roughly 30 to 50 percent of pregnancies end in miscarriage, says biologist Pablo A. Nepomnaschy of the National Institute of Environmental Health Sciences in Research Triangle Park, N.C. That number is imprecise because many miscarriages occur within days of conception, before a woman knows that she is pregnant. Miscarriage is a natural process that evicts defective embryos that are unlikely to survive, Nepomnaschy says, but the high rate suggests that other factors also play a role.