Academics help shape new national position on medicines in pregnancy

The statement, with involvement from Dr Cleodie Swire, Dr Reya Shah and Dr Dagan Lonsdale, calls for clearer, evidence-based guidance on the use of medicines during pregnancy and breastfeeding. It draws attention to significant evidence gaps, inconsistent advice for patients, and the longstanding exclusion of pregnant and breastfeeding women from clinical trials.

More than 80% of women in the UK take at least one medication during pregnancy or breastfeeding, yet limited safety and efficacy data often lead to uncertainty, anxiety, and avoidable changes to essential treatment. This work stresses that maintaining good control of maternal health conditions is crucial for the wellbeing of both mother and child.

The statement also reflects experiences that show how unclear guidance can leave women feeling unsupported and at risk of poorer health outcomes. It emphasises that physiological changes during pregnancy can impact both the exposure to, and the effects of, a medication. It also highlights the consequences of limited research and awareness such as hesitancy to use medications, which can lead to other significant risks through undertreated illness and unnecessary avoidance of medicines.

The BPS is calling for a major shift in how we develop knowledge about new medicines so that pregnant and breastfeeding women are no longer excluded. The position statement highlights research methods that could be utilised in this patient group. It includes pharmacokinetic modelling, a field of quantitative science that Dr Lonsdale and Dr Swire work on at City St George’s.

Clear direction for change

Dr Cleodie Swire, Registrar and Honorary Clinical Lecturer in Clinical Pharmacology, is one of the authors. She said:

Every woman deserves to be supported to make an informed choice about medication use when pregnant or breastfeeding. By strengthening the evidence base and improving the clarity of advice, we can help ensure that women and their babies receive care that fully reflects their needs.

Dr Dagan Lonsdale, Reader in Clinical Pharmacology and Intensive Care Medicine, and Vice President (Clinical) of the BPS, said:

A lack of high‑quality research in this space leaves women and their doctors in an invidious position. They have to make choices about important treatments for their medical problems without always having a full understanding of the risks of taking, or not taking, a medicine. It is important that we address this long‑standing challenge and set a clear direction for change.

Read the position statament.