Prospective and Dyadic Associations Between Expectant Parents’ Prenatal Hormone Changes and Postpartum Parenting Outcomes

During the transition to parenthood, both men and women experience hormone changes that are thought to promote parental care. Yet very few studies have explicitly tested the hypothesis that prenatal hormone changes are associated with postpartum parenting behavior. In a longitudinal study of 27 first-time expectant couples, we assessed whether prenatal hormone changes predicted self and partner-reported parenting outcomes at three months postpartum. Expectant fathers showed prenatal declines in testosterone and estradiol, and larger declines in these hormones predicted larger contributions to household and infant care tasks postpartum. Women whose partners showed larger testosterone declines also reported receiving more support and more help with household tasks. Expectant mothers showed prenatal increases in testosterone and estradiol, and larger increases predicted lower partner-rated support. Together, our findings provide some of first evidence that prenatal hormone changes may indeed be functional and that behaviors associated with these changes may be detectable by co-parents