Any pregnant woman who has ever cracked open a medicine cabinet is familiar with the warnings against using nearly every kind of medication, including those sold over the counter, from the moment of conception onward. Yet each year in the U.S., some 500,000 pregnant women battle psychiatric illness, cancer, autoimmune disease, influenza and other conditions that require treatment. Leaving aside for a moment the issue of whether the benefits of certain drugs outweigh the risks to the baby, what is the appropriate dosage for a mom-to-be? Given the shifts in her metabolism, how much she should take is often anyone's guess.
In the event of an anthrax scare, for example, the American College of Obstetricians and Gynecologists recommends that pregnant women take amoxicillin. But an obstetrics researcher in Seattle recently concluded there's no way to give a pregnant woman enough of the antibiotic to be effective. Kidney function is so revved up during pregnancy that even in high doses, amoxicillin is excreted before it can work its magic. Think of it as trying to fill a bathtub with the drain open, suggests Jason Umans, an internist and maternal-fetal pharmacologist at Georgetown University. "In emergencies, you always hear, 'Treat the pregnant women first!'" he says. "The joke should be 'Yeah, how?'" (See how the FDA classifies drugs and their effects on pregnancy.)
To start formulating an answer, an élite group of some 30 doctors, ethicists, scientists and government officials gathered in Washington this spring to launch a movement they're calling the Second Wave of clinical research. (The first happened in the early '90s, when studies began to include large numbers of women.) A conclave of maternal-health advocates is now pushing for better information on how drugs affect pregnant women.
A recently as 20 years ago, some in the medical community were still using the male body as their research prototype and extrapolating for women. The approach, as summarized by Anne Drapkin Lyerly, an obstetrician and bioethicist at Duke University, was "If you happen to have boobs and a uterus, then we'll adjust things."
Because drugmakers now include women and, thanks to a 2003 law, children in appropriate drug studies, Second Wave organizers are hoping to push federal agencies to gather more data on pregnant women what they're taking and with what effects and draw more blood samples so doctors can prescribe an effective dosage rather than winging it.
"Everyone thinks, Oh, my God, research on pregnant women! All kinds of ethical flags go up," says Ruth Faden, director of the Berman Institute of Bioethics at Johns Hopkins University. "We don't have to start with high drama." There's enough "low-hanging fruit," she says, "that we could keep lots of medical researchers busy for a long time."
Chronic illnesses like depression, diabetes and hypertension don't magically disappear during pregnancy. And as women delay childbearing, more moms-to-be are struggling with cancer. So it's hardly surprising that two-thirds of women take up to five drugs over the course of their pregnancy and labor. Yet only a dozen prescription drugs are approved for use by the U.S. Food and Drug Administration (FDA) during pregnancy, and they're all pregnancy-related: drugs for inducing labor, for example, or epidural anesthesia. Which means patients with many common conditions face an excruciating dilemma: decline medication whose effects on a fetus may be largely unknown or take it and worry about the consequences.