Safety concerns drive call for drug studies that involve pregnant women

November 09, 2008|By Stephanie Desmon | Stephanie Desmon,

Very few drugs are approved for use during pregnancy. Yet millions of pregnant women each year take prescribed medication to treat high blood pressure or depression or cancer, without meaningful data on whether the drugs are safe for them or their fetuses.

Many researchers have long considered including pregnant women in their studies taboo. But a push is on to learn more, amid fears that leaving serious health problems untreated could be more dangerous for pregnant women and their babies than taking an unstudied medication.

"I can't identify any other group that has been as systematically neglected" in biomedical research, said Ruth Faden, director of the Johns Hopkins Berman Institute of Bioethics.

Others worry that fetuses could be hurt by clinical research and that it would be difficult, if not impossible, to recruit enough pregnant women to participate. Many haven't forgotten the horror story of the morning sickness medication Thalidomide, which caused severe limb deformities in thousands of children after their pregnant mothers took the drug in the late 1950s and early 1960s.

"We can't throw [women] into studies who are pregnant just to see," said Dr. Hugh E. Mighty, an obstetrician/gynecologist at the University of Maryland Medical Center.

No one is suggesting women be included in every study of every drug. But Faden - who is co-hosting a conference on the subject this spring - thinks mothers and their children can be kept safe even as researchers find creative ways to study the risks, benefits and proper dosing of medications in pregnancy.

She wants to see review boards at hospitals and academic institutions, the gatekeepers to research, develop ethical guidelines for including pregnant women whenever possible.

"It's really controversial," said Dr. Donald Mattison, a senior adviser at the National Institute of Child Health and Human Development. "There are some groups who believe it's completely inappropriate, and others who are outraged that more hasn't been done."

In the meantime, Faden and others say, obstetricians and patients are often forced to make treatment decisions without all the facts.

"Pregnant women sometimes feel like they're put in a situation where they feel they have to choose between their own well-being and what's best for their baby," said Dr. Karen Feibus, who heads the maternal health team at the Food and Drug Administration's Center for Drug Evaluation and Research.

"Some women feel guilty for taking medication. That's not good for their health or the health of their baby," Feibus said. "There isn't enough well-vetted, data-based information out there to let them know ... what their decisions should be based on."

Just a dozen medications have been approved for use in pregnancy, all of them for gestation- or birth-related issues such as inducing or delaying labor, regional anesthesia or nausea and vomiting.

Any drug used to treat a pregnant woman's illness is used without FDA approval, though doctors prescribe medicine to pregnant women all the time to treat their illnesses.

Depressed women, diabetic women, asthmatic women - they all get pregnant. More than 4 million women give birth in the United States every year, and two-thirds use four to five medications during pregnancy and labor. Since many pregnancies are unintended, fetuses are often accidentally exposed to medications whose risks are not fully known.

A 2002 review of fetal risk associated with all 468 medications approved for human use in the U.S. from 1980 to 2000 reveals just how little is data is available. In a paper published this fall in the International Journal of Feminist Approaches to Bioethics, Faden and two colleagues wrote that only 6.4 percent of medicines were recognized as safe in pregnancy, while 2.5 percent were associated with "some risk."

"This leaves us without any substantive guidance regarding the risk to the fetus of more than 91 percent of drugs on the market," they wrote.

The lack of information is especially notable since many pregnant women are anxious about everything that goes into their bodies. Should they eat fish or avoid it? Should they color their hair? Are ACE inhibitors, a popular hypertension medication, safe in the first trimester or not? How about something as simple as cold medicine?

"We drive ourselves nuts," Faden said. "But we don't have much to help us."

Stacy Sledge was diagnosed with the autoimmune disease lupus in 2002. She was in her early 20s and knew she wanted children, but worried about whether her disease would allow her to have a healthy baby. Women with lupus have a high number of late miscarriages and a tendency to go into early labor; their babies are at risk for developing cardiac problems.

"If you do an Internet search on pregnancy and lupus, you find some pretty scary information out there," said Sledge, who lives in Arlington, Va.

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