Intended for healthcare professionals


Post-marketing surveillance should include effects during pregnancy

BMJ 2005; 330 doi: (Published 03 February 2005) Cite this as: BMJ 2005;330:308
  1. Patricia Yeargin, associate medical editor, health promotions (yeargin2000{at}
  1. American Cancer Society, 1599 Clifton Road, NE, Atlanta, GA 30329

    EDITOR—I agree that post-marketing surveillance of drugs is desperately needed.1 I further believe that, since information about drugs' effects during human gestation is never studied during pre-marketing, some post-marketing study of fetal effects during pregnancy should be considered.

    I have seen many women's medical care neglected during pregnancy owing to fear of harming the fetus, even when there is no real evidence that fetal harm is imminent. Currently we have only animal models, which apparently overstate risk: out of about 1200 known animal teratogens, only about 30 are known to be teratogenic in humans. It is very difficult for clinicians to weigh and explain competing risks when so few data are available on human fetal risk for so many important drugs. Unfortunately, this lack of information can lead to inadvertent fetal and maternal harm.

    The antiretroviral drugs, many of which are classified as category C but still must be used during pregnancy, are a case in point. A group of manufacturers of antiretrovirals funded a registry in the United States, in which this information is collected and used to guide clinicians in treatment decisions for pregnant women ( It is most helpful when talking about treatment with pregnant women, who have absorbed the notion that they should not take any drug treatment during pregnancy.

    This kind of registry must be different from mere reporting of adverse outcomes. For helpful information to be accrued, all sorts of exposures to various drugs during pregnancy would need to be reported. It would require educating clinicians and setting up easy reporting mechanisms. The women could then be followed until pregnancy outcome.

    Because of the limitations on testing drug treatments on pregnant women,2 collecting data on these unusual exposures is about the only way to get the information. It would certainly take a commitment, but it would also seem to be worthwhile.


    • Conflict of interests None declared


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