In any pregnancy, there is about a 3 per cent risk of delivering a baby with a birth defect (that's 3 out of every 100 babies born). Most of the causes of these birth defects are unknown – but medication exposures are known to cause very few. The vast majority of drugs and vaccines do NOT cause fetal harm.

Pregnant women get sick and sick women get pregnant. In addition to pregnancy-specific complications like gestational diabetes and pre-term labor, medical conditions that occur in non-pregnant women occur in pregnant ones as well, including psychiatric illness, cancer, and infectious diseases. Untreated medical conditions can have a devastating impact on your health and on the health of your baby.

To discover the most effective treatments for illnesses, scientists conduct research. But most studies do not allow pregnant women to participate in order to avoid accidently harming a fetus. However, the absence of research data on the safety and effectiveness of medications results in you and your doctor making treatment decisions based on very little information.

Because pregnant women have not been invited to join clinical studies, we do not know if they would volunteer to participate. Of course, pregnant women would only be asked to participate:

  1. If they were in need of the treatment and
  2. If the potential benefits of the treatment were way higher than the potential risks to herself and her baby and
  3. The medication was proven to be effective in non-pregnant women and
  4. The medication did not cause birth defects in pregnant animals.

Under those circumstances, participation would be very much like what happens now in your doctor’s office – you are prescribed medication that has not been tested in pregnant women. In a research study you’d have the added benefit of improved informed consent, closer pregnancy monitoring, and your knowledge that you have contributed your experience to the medical knowledge that will assist other pregnant women.

So what about you? Would you participate?


  1. Centers for Disease Control and Prevention. (2011). Birth defects. Washington, DC: Author. Retrieved Oct. 28, 2011.
  2. Brent, R.L. (2004). Environmental causes of human congenital malformations: The pediatrician’s role in dealing with these complex clinical problems caused by a multiplicity of environmental and genetic factors. Pediatrics, 113(4), 957-968, p. 958. PubMed.
  3. Koren, G., Pastuszak, A., & Ito, S. (1998). Drugs in pregnancy. New England Journal of Medicine. 338, 1128-1137, p. 1131.
  4. Baylis, F. (2010). Opinion: Pregnant women deserve better. Nature, 465, 689-670, p. 689.