Fatness at birth predicts adult susceptibility to ovarian suppression: An empirical test of the Predictive Adaptive Response hypothesis

Poor fetal environments are thought to produce adaptive changes in human developmental trajectories according to the Predictive Adaptive Response hypothesis. Although many studies have demonstrated correlations between indicators of fetal environment and negative adult health outcomes, the adaptive significance of these outcomes is unclear. Our study explicitly tests the adaptive nature of fetal programming in humans. We show that differences in nutritional status at birth are associated with adaptive differences in the sensitivity of adult ovarian function to energetic stress. Women who were born as relatively fat babies do not exhibit ovarian suppression in response to moderate levels of physical activity at adulthood, in contrast to women who were born as skinnier babies. The levels of estradiol in women born in the highest tertile of ponderal index (an indicator of neonatal nutritional status) were 37% and 46% higher, respectively, than levels of estradiol in women born in the low and middle ponderal index tertiles. These findings suggest that fetal programming of reproductive function results in developmentally plastic, but essentially adaptive, shifts in set points of ovarian response to energetic stress, such that women who were gestated under conditions of energetic constraint show greater sensitivity to energetic stress in adulthood. Our results have practical implications in terms of behavioral strategies for reducing the risk of breast cancer. We suggest that the amount of activity necessary to reduce levels of estrogen, which may in turn reduce cancer risk, can depend on a woman's nutritional status at birth.