Examining the link between women's exposure to stressful life events prior to conception and infant and toddler health: the role of birth weight

Abstract

Background: The life course perspective suggests a pathway may exist among maternal exposure to stressful life events prior to conception (PSLEs), infant birth weight and subsequent offspring health, whereby PSLEs are part of a 'chains-of-risk' that set children on a certain health pathway. No prior study has examined the link between PSLEs and offspring health in a nationally representative sample of US mothers and their children. We used longitudinal, nationally representative data to evaluate the relation between maternal exposure to PSLEs and subsequent measures of infant and toddler health, taking both maternal and obstetric characteristics into account.

Methods: We examined 6900 mother-child dyads participating in 2 waves of the nationally representative Early Childhood Longitudinal Study-Birth Cohort (n=6900). Infant and toddler health outcomes assessed at 9 and 24 months included overall health status, special healthcare needs and severe health conditions. Adjusted path analyses examined associations between PSLEs, birth weight and child health outcomes.

Results: In adjusted analyses, PSLEs increased the risk for very low birth weight (VLBW, <1500 g), which, in turn, predicted poor health at both 9 and 24 months of age. Path analyses demonstrated that PSLEs had small indirect effects on children's subsequent health that operated through VLBW.

Conclusions: Our analysis suggests a chains-of-risk model in which women's exposure to PSLEs increases the risk for giving birth to a VLBW infant, which, in turn, adversely affects infant and toddler health. Addressing women's preconception health may have important downstream benefits for their children, although more research is needed to replicate these findings.

Keywords: BIRTH WEIGHT; CHILD HEALTH; Life course epidemiology; MATERNAL HEALTH; PSYCHOSOCIAL FACTORS.

Figure 1

Figure 1 displays the direct and indirect effects included in the path models. Primary direct effects of interest (depicting relationships among exposure to stressful life events prior to conception, infant birthweight, and child health outcomes) are shown with solid black arrows. Direct effects for groups of adjustment variables are shown with solid gray arrows. Maternal factors are depicted in pink and infant and child outcomes are depicted in green. Variables included as sociodemographic factors are: maternal chronic conditions, number of children born, parity, maternal age, race/ethnicity, marital status, health insurance status, socioeconomic status, and region of residence. Variables included as pregnancy-related factors are: pregnancy complications, prepregnancy body mass index, and initiation of prenatal care. Specific indirect effects are shown as dashed black arrows, and map the hypothesized pathway through intermediate variables.

Figure 2

Figure 2 summarizes the path analyses results of selected direct and total indirect effects of maternal exposure to stressful life events in the preconception period on very low birthweight and child health at 9 and 24 months of age. Weighted results are presented as percent changes and corresponding 95% confidence intervals, controlling for pregnancy complications, maternal chronic conditions, prepregnancy body mass index, initiation of prenatal care, plurality, parity, exposure to any stressful life event during pregnancy, maternal race/ethnicity, maternal age, marital status at birth, health insurance coverage, family socioeconomic status, and US region of residence. Direct effects from very low birthweight status to each child health variable at 24 months are also included. Solid lines represent direct effects and dashed lines indicate total indirect effects. SHCN = Special health care need.