At the time of the drug's development, scientists did not believe any drug taken by a pregnant woman could pass across the placental barrier and harm the developing fetus, even though the effect of alcohol on fetal development had been documented by case studies on alcoholic mothers since at least 1957.
No momento do desenvolvemento do fármaco, os científicos non crían que os fármacos que tomaban as mulleres embarazadas puidesen atravesar a barreira placentaria (que separa as circulacións sanguíneas materna e fetal) e que puidesen danar ao feto en desenvolvemento, a pesar de que o efecto do alcohol sobre o desenvolvemento do feto xa estaba documentado en estudos de casos de nais alcohólicas desde polo menos 1957.