Post-traumatic stress disorder and adverse pregnancy outcomes: sexual orientation disparities in a prospective cohort study

Background: Post-traumatic stress disorder (PTSD) is a recognized risk factor for adverse pregnancy outcomes. Growing research indicates that sexual minority (SM) people face elevated risks for both PTSD symptoms/diagnosis and adverse pregnancy outcomes. However, no research has examined whether the association between sexual orientation and adverse pregnancy outcomes differs by PTSD symptoms/diagnosis. 

Methods: We used longitudinal data from the Nurses’ Health Study 3, a longitudinal cohort of nurses born on or after January 1, 1965, living in the US or Canada. We restricted analyses to those who reported their sexual orientation, completed the questionnaire with PTSD items, and had at least one pregnancy (N = 27,381 pregnancies from 10,090 participants). We examined whether the associations between sexual orientation and six adverse pregnancy outcomes) differed by PTSD symptoms/diagnosis prior to pregnancy across sexual orientation subgroups: completely heterosexual (reference), heterosexual with same-sex experience, mostly heterosexual, bisexual, and lesbian/gay. We used modified Poisson models to estimate risk ratios (RRs) for PTSD symptoms and diagnosis. Next, we examined whether sexual orientation and six adverse pregnancy outcomes (i.e., gestational diabetes, gestational hypertension, preeclampsia, preterm birth, low birthweight, macrosomia) varies by PTSD symptoms/diagnosis. 

Results: Compared to completely heterosexual participants, all SM subgroups had higher risks of PTSD symptoms prior to pregnancy (heterosexual with same-sex experience RR 1.23, 95% CI, 1.17–1.29; mostly heterosexual RR 1.37, 95% CI, 1.31–1.43; bisexual RR 1.58, 95% CI, 1.49– 1.67; lesbian/gay RR 1.46, 95% CI, 1.30 − 1.63) prior to pregnancy. SM participants (subgroups combined) had 2.6 times the risk of PTSD diagnosis (RR 2.64, 95% CI 1.38–5.05) compared to the completely heterosexual group. Sexual orientation disparities for low birthweight and preeclampsia were greater among those with, compared to without, PTSD symptoms; however, interaction tests of sexual orientation and PTSD symptoms were not significant. Pregnancies to SM participants (subgroups combined) with PTSD symptoms had a significantly higher risk of low birthweight than pregnancies to completely heterosexual participants; there was no significant difference among those without PTSD symptoms. Conversely, sexual orientation disparities in gestational hypertension were greater among pregnancies without PTSD symptoms, though the interaction was not significant. 

Conclusion: PTSD may lead to varied adverse pregnancy outcomes across sexual orientation groups. Screening for PTSD and using a trauma-informed approach to perinatal care is particularly critical for marginalized populations.