When a nine-week ultrasound revealed that she'd had a miscarriage, Lisa Pisha was desperate for answers. "I just wanted to know why I lost my baby," says Pisha, 30, of Naperville, Illinois. "Was it something I ate, or drank, or did during my pregnancy? Was it just a fluke?" But no one -- not her doctor or her friends, or even the miscarriage Web sites she studied -- could offer a definitive answer. "When I got pregnant again, I was on pins and needles for my entire first trimester," Pisha says. Fortunately, things went smoothly, and her daughter, Graham, was born last April.
Officially, about 15 percent of all known pregnancies end in a miscarriage, meaning they terminate before the 20th week. (After that, the loss is considered a stillbirth, according to the March of Dimes.) But experts say the actual number may be closer to 50 percent when it includes early miscarriages that happen before a woman even realizes she's pregnant. And virtually everyone, regardless of age, health, and previous successful pregnancies, is vulnerable. "No woman is immune," says Katherine E. Hartmann, MD, PhD, director of women's health research at Vanderbilt University Medical Center, in Nashville. Because miscarriages happen so often, most doctors don't even evaluate women until they've had at least two.
Still, women and physicians are understandably eager to learn more about what can trigger a miscarriage, and the latest research is uncovering some surprising possibilities.