Globally, more than 200 million women become pregnant each year, most of
whom receive medications despite limited information on their safe use
during pregnancy. The paucity of drug safety data on pregnant and
breastfeeding women stems from the routine exclusion of this population
from clinical trials due to scientific, ethical, regulatory and legal
concerns. Consequently, at the time of initial drug approval, there may
be scant safety data to inform the drug benefit-risk balance to the
mother, foetus, or infant. Although momentum is growing to include this
underrepresented population in clinical trials, most information on drug
exposure outcomes comes from data collected in the post-marketing
setting. Regulatory guidance and legislation on medication use in
pregnancy and breastfeeding were reviewed globally by TransCelerate IGR
PV Pregnancy and Breastfeeding Team. ICH standards and CIOMS guidelines
served as benchmarks for national safety regulations and guidance. The
landscape assessment identified a lack of harmonisation of global
regulations on research in pregnant and breastfeeding women. This
editorial focuses on the ambiguities and lack of harmonisation in global
regulations on post-marketing pregnancy and breastfeeding safety
studies. There is currently no ICH standard to guide these types of
safety studies and, in most regions reviewed, there are no clear
regulations or guidance on when and how to conduct them. While a
challenging undertaking, greater clarity and harmonisation would
facilitate more timely completion of post-marketing pregnancy safety
studies that would ultimately generate the critical data needed to
optimize benefit-risk decisions for pregnant and breastfeeding women.