Pregnancy is no reason to exclude women from clinical research, a new US paper argues. “While we’ve made significant progress in correcting the gender imbalance [in research], we have a long way to go in protecting the health and safety of pregnant women and the foetuses they carry,” says lead author Dr Anne Drapkin Lyerly.

Recognition that women in general were being excluded not only from the risks but from the benefits of clinical trials – mainly due to their potential to get pregnant or to concerns that female physiology, such as menstrual cycles, might complicate study results – has only come in the last two decades, notes Lyerly, an obstetrician/gynaecologist and medical ethicist at Duke University Medical Center in Durham, North Carolina.

Now it is time to confront the challenges keeping pregnant women out of important research that could have a positive impact on both maternal and foetal health, assert Lyerly and her co-authors – Margaret Little, a senior research fellow at Georgetown University’s Kennedy Institute of Ethics and Ruth Faden, executive director of the Johns Hopkins Berman Institute of Bioethics – in their paper for the November 2008 edition of the International Journal of Feminist Approaches to Bioethics.

The US Institute of Medicine has recommended since 1994 that pregnant women should be “presumed eligible” for participation in research, the authors point out. Yet the “delicate condition” continues to be grounds for near-automatic exclusion from trials, despite the need for more effective treatment for women during pregnancy.

Chronic hypertension and diabetes occur in nearly 4% of all pregnancies, while each year an estimated 500,000 pregnant women require treatment for psychiatric illness, cancers, autoimmune diseases and other conditions, the authors say. Without research on how drugs are actually metabolised, absorbed, distributed and excreted in pregnant women, though, doctors are often left guessing about how to treat patients safely and effectively.

“Our best predictions when it comes to dosing medications can be disastrously wrong,” Lyerly comments. “This conservative stance doesn’t help anybody.”

In an effort to push the debate forward, the paper’s authors are convening a meeting with officials from the US Food and Drug and Administration and the National Institutes of Health, as well as leading experts in obstetrics, gynaecology and maternal/foetal medicine, next year to address these issues and come up with practical, ethical and public-policy solutions.

“It’s not simply a matter of including pregnant women in studies,” Lyerly adds. “We need to address what we need to do to ensure maternal and foetal safety, which diseases we should study first, and what we should do when pharmaceutical companies or institutions say no.”