Protecting or harming? The exclusion of pregnant women from the Covid-19 vaccine trials

Around the world we have been hearing and reading about the development and roll out of the Covid-19 vaccine. With the release of the vaccine comes details of those who are excluded from the opportunity to take it; one of the largest groups excluded in the UK are pregnant women due to the lack of testing in this population and ‘as a matter of caution’ (Public Health England (PHE), 2021).

In April 2020, of 155 Covid-19 treatment studies of non-biological drugs, 80% of them excluded pregnant women, and by July 2020 of 722 studies, 75% excluded pregnant women (Taylor et al., 2020). In April 2020, only four studies of 588 global clinical trials for the Covid-19 vaccine were specifically designed for pregnant women (Constantine et al., 2020). Taylor and colleagues argue that these exclusions were not well justified, with many of the treatments evaluated as having low or no safety concerns during pregnancy.

A history of women in clinical trials

But why is this? Clinical trials have typically excluded pregnant or breastfeeding women from research for some time (Knight et al., 2020). This exclusion dates back to the 1960s and the events that unfolded in what came to be known as the Thalidomide Tragedy (McBride, 1961).

Thalidomide, advertised as ‘completely safe’ (Fintel et al., 2009), was prescribed to many women for morning sickness, a trend started by Australian doctor, William McBride. It was eventually banned in most countries in 1962 after Dr McBride began to identify birth defects, including missing or shortened limbs, in the babies he delivered whose mothers had used thalidomide in pregnancy (McBride, 1961).

It was this tragedy that led to the US Food and Drug Administration (FDA) to exclude pregnant women, and also women of childbearing age, from biomedical research. In 1993 this exclusion was reduced to pregnant women only (Macklin, 2010). While there has been some movement in the inclusion of pregnant women in research, this ‘protection by exclusion’ (Constantine et al., 2020, p.2) is not new to the Covid-19 vaccine but arguably systematic in medical research (DeBruin, 1994).

The call for women to be included in trials

In 2021, there is a growing call for pregnant women to be given the opportunity to be included in more medical research, including research around Covid-19 and its vaccine (Beigi et al., 2021; Constantine et al., 2020; Knight et al., 2020). Excluding women from clinical trials results in a lack of knowledge about the risks and potential benefits of products (Macklin, 2010) and has held back our ability to provide appropriate care for pregnant women.

But is the decision by the medical majority to exclude women fair? Or is it a method of risk management that has led to women being underrepresented in health research that impacts them? Constantine (et al) argues that pregnant women are capable of reflecting on the ethical implications and consequences of health decisions for them and their foetuses. Similarly, Yakerson (2019) recommends that rather than outright exclusion, pregnant women should be included in research unless there is a reasonable justification that they should not be.

In the UK, rather than include pregnant women in clinical trials, those given a Covid-19 vaccine in pregnancy will be registered to the UK Vaccine in Pregnancy surveillance programme (PHE, 2021), a programme which monitors and collates information about various vaccines and their impact on pregnancy. The question left to us then is whether this is enough to enable informed and appropriate health care and advice for pregnant women, and should they have a choice in their inclusion in medical trials? In short: are we protecting or harming pregnant women when excluding them from medical research?