Use of medication during pregnancy should be avoided if at all possible. However, there are those instances where such use cannot be avoided and not using the medication poses a greater risk to both mother and her unborn child than treating the problem. Consider, for example, women with asthma, diabetes, amebic infections, other infections, hypertension or significant depression. In these instances, providing no treatment is not an option when considering the safety of either the mother or the fetus. As a society, we tend to pretend that these conditions do not exist and continue to advocate that no medications should be used during pregnancy. With that stance, the mother and physician or other health care professional are left to determine how to handle the situation with no guidance.
Few medications are studied for use during pregnancy before being marketed. Information on teratogenic potential of a medication is picked up in post marketing surveillance. It took almost four years of marketing before the link between thalidomide and its devastating teratogenic effects were recognized. Malformations with warfarin took over 20 years to identify. Reproductive tract abnormalities with DES also took many years to identify.
The following are some examples of situations during which the physician and pregnant woman are going to have to consider very carefully whether use of medication is in the best interests of both the mother and her unborn child:
- Awoman with arrhythmias controlled with medication, who becomes pregnant.
- Awoman with epilepsy controlled with medication, who becomes pregnant.
- Awoman with diabetes controlled with medication, who becomes pregnant.
- Awoman who is infected with a parasite during her pregnancy.
- Awoman who develops meningitis during her pregnancy.
- Awoman who develops pneumonia during her pregnancy.
There are many examples of situations where the decision to use or not to use medication is unclear. When treatment is of necessity, the next questions raised are which medications are currently recognized to be safe and which ones to chose. Healthcare professionals and their patients both need to have access to the best information available in order to make an informed decision for both the mother and her unborn child.
In the United States, the Food and Drug Administration has issued four guidelines to help address this situation in that country.
- Evaluating the Risks of Drug Exposure in Human Pregnancies (2005) – This guidance provides assistance on how to evaluate human data on the effects of in utero drug exposure on the developing fetus, i.e., how to go about determining whether or not there is a causal link between the use of the medication and the effect seen.
- Lactation Studies in Women (2005) – This is a draft guidance that provides a framework for designing, conducting and analyzing clinical lactation studies.
- Determining the Appropriate Dose of a Drug for Pregnant Women (2004) – This is a draft guidance that provides the framework for designing, conducting and analyzing pharmacokinetic and pharmacodynamic studies in pregnant women. In almost all cases, the efficacy of the drug has already been established in the greater adult population.
- Pregnancy Exposure Registries (2002) – This is a guidance addressing the issue of establishing registries that prospectively monitor the outcomes of pregnancies in women exposed to a medication.
The Canadian Alliance for Safe and Effective Medications in Pregnancy and Breastfeeding (CaseMed-Pregnancy) is an Alliance that is drawn from health professions, academia, patients, government, regulatory affairs personnel and industry. Currently, the following individuals serve as members of this Alliance:
- Anne M. Tomalin, President, CanReg Inc., Hamilton, Ontario – Chair
- Mercedes Benegbi, Thalidomide Victims Association of Canada, Montreal, Quebec
- Carole Boyer, Duchesnay Inc., Laval, Quebec
- Donald Davis, M.D., President, Society of Obstetricians and Gynecologists of Canada, Medicine Hat, Alberta
- Gideon Koren, M.D., Ph.D., Motherisk Program, Hospital for Sick Children, Toronto, Ontario
The Mandate of the Canadian Alliance for Safe and Effective Medications in Pregnancy and Breastfeeding is to advocate for maternal/foetal and breastfeeding health and safety issues, particularly with regards to the safety of medications.
The Goals of the Alliance are:
- To have pregnant women and their fetuses recognized as a vulnerable patient population.
- To place these issues higher on the strategic agenda of Health Canada, the medical community and the pharmaceutical industry.
- To insist that health care professionals and patients have access to current and reliable information on the safety and efficacy of medications used during pregnancy and breastfeeding.
- To advocate for the development of patient registries and follow-up for the use of medications during pregnancy and breastfeeding in Canada to further develop our knowledge of the use of medications and their potential effects in these vulnerable populations.
If you would like further information about the Alliance, please visit our website at www.CaseMed-Pregnancy.org