Temporal Associations between Prenatal Psychosocial Context and Birth Outcomes

Background: In the United States approximately one in eight babies is born preterm (before 37 completed weeks gestation), and one in twelve infants are born low birthweight (<2500 grams). These poor birth outcomes lead to neonatal morbidity and mortality as well as lifelong developmental and health issues that affect both the quality of life for families and convey a costly economic burden to these families and the public. Psychoneuroimmune interactions in response to stressful events or conditions alter cell signaling throughout the body During pregnancy, the maturing placenta is an active endocrine and immune organ; however, its’ contributions to stress processing evolve as the pregnancy progresses. Approximately thirty percent of preterm births are attributable to endocrine immune changes that are related to stress processing.
Purpose: To evaluate the evolutionary framework of Adaptive Reproduction a theoretical basis for understanding how environmental stressors and psychoneurological states impact birth outcomes. Two hypotheses were tested: 1) does the impact of stress, depression, tobacco use and social support on adverse birth outcomes vary across the gestation? And 2) does the experience of perinatal intimate partner violence (IPV) affect the timing of the impact of stress, depression, tobacco use and social support on birth outcomes?
Sample and Setting: The sample included women involved in the BabyBEEP study (R01 NR05313) that evaluated the efficacy of a smoking cessation intervention for low-income pregnant women (N=695). Data was collected between 2002 and 2006 in 21 counties in rural Missouri. Thirty-four percent of the sample experienced perinatal intimate partner violence.
Methods: Data was restructured for secondary analysis using a multilevel structural equation model.
Findings: Both hypotheses were supported by the analysis. When controlling for the other variables, stress and social support have paradoxical effects at different stages of pregnancy. In women experiencing perinatal IPV, depression, particularly prior to 24 weeks, is associated with both low birthweight and preterm birth.
Conclusion: Adaptive reproduction provides a plausible explanation for why psychoneuroimmune alterations sometimes lead to preterm birth and low birthweight . This provides a theoretical basis for how community and individual level preconceptional and prenatal interventions aimed at enhancing functional social support and stress resilience improve outcomes.