Thalidomide tragedy led to ethical concerns, cost, and legal risks preventing drug testing in pregnant women, resulting in common off-label use. Despite societal fears, medication use in pregnancy increased, with 63% of Danish pregnancies receiving at least one prescription in 2018. Barriers to testing include historical exclusion of pregnant women from trials, lack of incentives for drug companies, and prescriber/patient concerns. The WHO advocates for 'protection through research' to ensure safety.