Thalidomide was marketed in several parts of Europe in the 1950s and was prescribed as a totally safe sedative used in treatments of the morning sickness and insomnia associated with pregnancy, despite the fact that no safety testing had been done on pregnant animals.  It is sometimes argued that, in the 1950s, no new medicines were tested in pregnant animals because scientists did not yet understand that the foetus could be damaged by external factors.

By the late 1950s, babies were starting to be born with missing or shortened limbs, called phocomelia.  Doctors expect to see a small level of birth defects, but the numbers were much higher than normal.  Investigations began to try to find the cause. Later research showed that thalidomide would only damage the foetus if it was taken during a certain stage of pregnancy.  It also emerged that a flu treatment called Grippex contained thalidomide, and that mothers who thought they had not been exposed to the drug, had in fact taken it.