Illness Symptoms during Pregnancy Impact Offspring Development and Parental Behavior during the Postpartum Period

A pregnant person's brain undergoes structural and functional reorganization that is thought to help them orient toward parenting behaviors. Though illness during pregnancy has been found to influence neural development of offspring, much less is known about whether prenatal illness influences neural reorganization of the pregnant parent and whether that could cause a shift in parental reproductive investment. We conducted a secondary analysis of data collected from 157 mixed-sex couples who were recruited from the community who participated during pregnancy, 6 months and 1 year postpartum. Birthing parents reported on general health and acute illness during their pregnancies, from which we derived a proxy measure of immune activation. At 6 months postpartum, both parents reported on infant socioemotional function and mothers reported on bonding impairments with infant. Both parents reported sexual frequency across the perinatal period. Finally, parents reported quality of partner support during pregnancy, household size, and income/poverty status. Using structural equation modeling, we created a robust, reliable, and reproducible measure of prenatal maternal immune activation that predicted greater infant socioemotional difficulties at 6 months postpartum. These infant difficulties were associated with (a) more parental impaired bonding with infant, regardless of access to resources and (b) less frequent sex at 1 year postpartum, controlling for prenatal sexual frequency and postpartum sexual function, but only for couples who fell below the poverty line. These findings suggest that parental immune activity during pregnancy has important implications for infant socioemotional development and parent investment in offspring, and that these effects might depend on resource availability.