Repetitive negative thinking during pregnancy and postpartum: Associations with mental health, inflammation, and breastfeeding

Introduction: Repetitive negative thinking (RNT) is a transdiagnostic feature that predicts increased mental health risks, inflammation, and reduced engagement in health promoting behaviors. Depression, anxiety, stress, inflammation, higher body mass index (BMI), and low engagement in health behaviors are associated with adverse outcomes during pregnancy as well as postpartum. However, there is limited literature on the associa-tions between RNT and these contributing factors in the perinatal period, an at-risk time during which women may benefit from clinical interventions directed at RNT.Methods: This study examined the contribution of RNT to inflammation [interleukin (IL)-6] and breastfeeding duration through mediating indicators of mental health and BMI. Behavioral and biological assessments occurred during late pregnancy as well as at 4-6 weeks, 4 months, 8 months, and 12 months postpartum.Results: RNT was positively associated with depressive symptoms, anxiety, and perceived stress (ps <= .001) at each assessment timepoint, with the strongest associations observed at the pregnancy assessment and significant, but attenuated, associations during postpartum (ps < .01). In modeling of the association between RNT and IL-6, the indirect effect of BMI was significant at each timepoint (95%CIs 0.0013, 0.0052). Women with lower RNT exhibited longer breastfeeding duration (p = .02). These effects were not significantly mediated by mental health indicators.Conclusions: Clinically meaningful relationships, in which RNT predicts mental health, inflammation, and health behavior engagement during pregnancy and postpartum were observed. Clinical interventions to reduce RNT may have unique benefits this time.Limitations: Further research is warranted to determine if therapies to reduce RNT confer unique benefits for maternal and child health.