before the 1960s, many countries did not have rules about testing medications for their effects on fetuses. this changed partly because of thalidomide. this medication was given to pregnant women for nausea in the 1950s and 1960s. between 1956 and 1962, more than 10,000 children in 46 different countries were born with birth defects, like arms and legs that had not grown. thalidomide had not been tested well enough before it started being prescribed. now, many countries require more testing before a medication can be said to be safe during pregnancy.