Alcohol and other blood-borne drugs easily crosses the placental barrier, thus passing from mother to child. Depending on the level and the duration of alcohol in women during pregnancy, the consequences vary : spontaneous abortion, premature labour, still births, and foetal alcohol syndrome, characterized by malformations and retarded physical and mental development.
In ancient Carthage there existed a ban against consuming liquor on the wedding night for fear that a defective child be conceived. Plato suggested that alcohol should be barred "to any man or woman who was intending to create children; children should not be made in bodies saturated with drunkenness".
According to one survey, in excess of 11% of all infants born in the USA in 1988 tested positive for alcohol or cocaine the first time their blood was drawn. The State Assembly Committee on Alcoholism and Drug Abuse estimated that 12,000 babies would be born addicted in New York City in 1989, and the number of children in foster care has doubled in two years from 27,000 in 1987 to more than 50,000, mainly because of parental substance abuse.
An estimated 1 in 3 women continue to smoke throughout her pregnancy.