"Illicit drug use by women is also not new. By the end of the 19th century, almost two thirds of the nation's opium and morphine addicts were women . The issue of drug use during pregnancy garnered the national spotlight starting in the 1960's when public attention began to focus on the possible harm to the unborn child. Less than 15 years after Chuck Yaeger shattered the sound barrier, several events combined to shatter the placental barrier – the notion that the fetus was protected and even invulnerable. The placental "barrier" suddenly became quite porous. The rubella (German measles) epidemic and, in particular, the tragedies caused by two drugs, thalidomide and diethylstilbestrol (DES), amplified public sentiment about the need for protecting the fetus from risks from drug use. Thalidomide was approved for marketing in 1958 and was used primarily as a sedative and antidote for nausea in early pregnancy. By 1962, evidence showed that a rare set of deformities, mostly limb malformations, were caused by the drug and 8,000 children had been affected . DES was a synthetic hormone prescribed in the 1940s and 1950s to prevent miscarriage. By the late 1960s and 1970s, the side effects of the drug became known: the daughters of women who had taken DES during pregnancy developed a rare adrenocarcinoma of the vagina. Licit and illicit drugs became suspect as possible teratogens, and the activities, diet and behaviors of pregnant women have been under close scrutiny ever since ."
Lester, Barry M.; Andreozzi, Lynne; Appiahm, Lindsey, "Substance use during pregnancy: time for policy to catch up with research," Harm Reduction Journal (London, United Kingdom: April 2004) Volume 1, Issue 5, p. 2.