Experts stress the urgent need to include more pregnant and lactating women in clinical trials to close the significant gap in evidence for the use of drugs in these groups. In a statement, the British Pharmacological Society (BPS) calls for clearer evidence-based guidance on the use of medicines during pregnancy and breastfeeding. In the UK, more than 80% of women reported taking at least one medicine during pregnancy or breastfeeding. Antidepressants, iron supplements, antibiotics, and laxatives are among the most common. Stopping treatment for chronic or mental illnesses can endanger the health of both mother and child. Key recommendations include routinely including pregnant women in clinical research when safe and appropriate. Post-marketing and real-world data must be maximized to reduce healthcare inequities and improve safety.