BACKGROUND
Sexual minority (SM) individuals (e.g., those with same-sex attractions/partners or who identify as lesbian/gay/bisexual) experience a host of physical and mental health disparities. However, little is known about sexual orientation-related disparities in gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP; gestational hypertension [gHTN] and preeclampsia).
OBJECTIVE
To estimate disparities in GDM, gHTN and preeclampsia by sexual orientation.
METHODS
We used data from the Nurses' Health Study II-a cohort of nurses across the US enrolled in 1989 at 25-42 years of age-restricted to those with pregnancies ≥20 weeks gestation and non-missing sexual orientation data (63,518 participants; 146,079 pregnancies). Our primary outcomes were GDM, gHTN and preeclampsia, which participants reported for each of their pregnancies. Participants also reported their sexual orientation identity and same-sex attractions/partners. We compared the risk of each outcome in pregnancies among heterosexual participants with no same-sex experience (reference) to those among SM participants overall and within subgroups: (1) heterosexual with same-sex experience, (2) mostly heterosexual, (3) bisexual and (4) lesbian/gay participants. We used modified Poisson models to estimate risk ratios (RR) and 95% confidence intervals (CI), fit via weighted generalised estimating equations, to account for multiple pregnancies per person over time and informative cluster sizes.
RESULTS
The overall prevalence of each outcome was ≤5%. Mostly heterosexual participants had a 31% higher risk of gHTN (RR 1.31, 95% CI 1.03, 1.66), and heterosexual participants with same-sex experience had a 31% higher risk of GDM (RR 1.31, 95% CI 1.13, 1.50), compared to heterosexual participants with no same-sex experience. The magnitudes of the risk ratios were high among bisexual participants for gHTN and preeclampsia and among lesbian/gay participants for gHTN.
CONCLUSIONS
Some SM groups may be disparately burdened by GDM and HDP. Elucidating modifiable mechanisms (e.g., structural barriers, discrimination) for reducing adverse pregnancy outcomes among SM populations is critical.