Why It’s Important to Test Drugs on Pregnant Women

By Mackenzie Graham

Crosspost from The Conversation. Click here to read the full article.

The development of accessible treatment options for pregnant women is a significant public health issue. Yet, very few medications are approved for use during pregnancy. Most drug labels have little data to inform prescribing decisions. This means that most medicines taken during pregnancy are used without data to guide safe and effective dosing.

The United States Food and Drug Administration recently published draft ethical guidelines for how and when to include pregnant women in drug development clinical trials. These guidelines call for “the judicious inclusion of pregnant women in clinical trials and careful attention to potential foetal risk”. The guidelines also distinguish between risks that are related to the research and those that are not, and the appropriate level of risk to which a foetus might be exposed.

Increasing the number of pregnant women enrolled in clinical research is not only morally permissible, it is morally required. The reason we conduct health research is its scientific and social value. The benefits and burdens of this research should be distributed fairly. Pregnant women have been excluded from clinical research, which has led to them being unfairly deprived of its benefits.

A major reason that pregnant women are underrepresented in clinical research is that they are considered a ‘vulnerable population’. Groups like children, women of reproductive age, pregnant women, and those with cognitive disability, have historically been excluded from participating in research, as a way of protecting them. However, there is no compelling reason for considering pregnant women a vulnerable population in this sense.

There is nothing specific about pregnancy that makes one unable to provide informed consent (as in children), or susceptible to influence or coercion. In fact, the strongest reason to consider pregnant women a vulnerable population is because they face an increased likelihood of risk from participating in research. But this is only because they have largely been excluded from research participation in the first place!

Including pregnant women in biomedical research is also complicated by the fact that it may present risks, as well as potential benefits, to both the future child and the pregnant woman. Ethics guidelines require that in cases where research participation has no prospect of direct benefit to the pregnant woman, the risks to the foetus must be ‘minimal.’ Minimal risk is generally understood as the risks involved in everyday life. When research does have the prospect of direct clinical benefit to the pregnant woman, an increase over minimal risk may be permitted.

These guidelines can be difficult to interpret. For example, the idea of ‘minimal risk’ is vague, and may depend on context. It is also unclear how much risk to a foetus is acceptable if there is a prospect of direct benefit to the pregnant woman. Suppose a treatment only available through research could save a pregnant woman’s life, but placed her foetus at a significant risk of being born with severe disabilities. Here, the potential benefits to the pregnant woman must be weighed against the potential risks to the future child. It is very often unclear how this balance should be struck.

Fortunately, a great deal of potential clinical research involving pregnant women does not require such a careful balancing of risks and benefits. Millions of pregnant women are already using various medications. They could easily form a research population investigating dosing and pregnancy outcome. Such studies would involve little or no additional risk to the foetus, or the pregnant woman.

Simply avoiding the issue is not a viable solution. Guidelines like those issued by the FDA are useful, and are needed to increase consistency in the regulation. Further funding for research investigating medications in pregnant women, and for pregnant women, is needed. Ethicists must continue to work to develop frameworks for managing the risk-benefit trade-offs between woman and foetus. Failure to do so will continue to deprive pregnant women of a fair distribution of the benefits of research.