Assertion: teratogen's effect | /r/HasProperty | documented by case studies
Facets:
value: since least 1957
type: TEMPORAL
value: on alcoholic mothers
type: OTHER
Source sentences:
text: 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.