Prenatal diethylstilbestrol exposure and performance on college entrance examinations

The fetal rodent brain is permanently altered by exposure to sex hormones. Long-term effects of prenatal sex hormones on the human brain are far less clear. In order to explore such effects, we studied a measure of cognitive function among young adults who had been exposed in utero to a powerful synthetic estrogen. In a randomized clinical trial conducted at the University of Chicago in 1950-1952, 1646 pregnant women were randomly assigned to receive either high doses of diethylstilbestrol or placebo. Women in this study gave birth to 1653 liveborn infants, of whom 1603 (820 sons and 783 daughters) survived to their fifteenth birthday. College entrance examination scores were obtained for 42% of these offspring. No differences in test performance were seen among exposed daughters. Among sons, test scores were marginally higher among the exposed, probably due to chance.