Maintaining factors of posttraumatic stress symptoms following childbirth: A population-based, two-year follow-up study.

BACKGROUND Previous research has established a number of risk factors that are associated with the onset of PTSD following childbirth. However, little is known about factors that maintain PTSD symptoms. METHODS This study is part of the Akershus Birth Cohort. Questionnaire data from pregnancy week 17, 8 weeks postpartum and 2 years postpartum were used. 1473 women completed all these three questionnaires and were included in the analyses. Post-traumatic stress symptoms were measured with the Impact of Event Scale. Potential maintaining factors were personality, sleep, support and life events. The factors that were significantly correlated with post-traumatic stress symptoms were entered into regression analyses. Mediation analyses were run to test whether significant predictors would serve as mediator of post-traumatic stress symptoms at 8 weeks postpartum to post-traumatic stress symptoms at 2 years postpartum. RESULTS We found several low to moderate associations between maintaining factors and PTSD symptoms two years postpartum. Adjusting for the starting point - PTSD symptoms 8 weeks postpartum - only insomnia remained significantly associated. Further, insomnia mediated a small portion of the effect of PTSD symptoms 8 weeks postpartum to PTSD symptoms 2 years postpartum. LIMITATIONS Limitations of the study include a relative homogeneous sample, modest effect sizes, low internal consistency of some of the measures and the challenge to distinguish insomnia from PTSD symptoms. CONCLUSIONS Treatment of postpartum PTSD might benefit from addressing insomnia if present. Alleviating insomnia may itself reduce daytime symptoms of PTSD and it may also increase the efficacy of primary PTSD treatments.