Background:

Many sexual and/or gender minority individuals build families through pregnancy and childbirth, but it is unknown whether they experience different clinical outcomes than non-sexual and/or gender minority individuals.

Objective:

To evaluate obstetric and birth outcomes among likely sexual and/or gender minority patients in comparison with likely non-sexual and/or gender minority patients.

Study design:

We performed a population-based cohort study of live birth hospitalizations during 2016-2019 linked to birth certificates in California. California changed its birth certificate in 2016 to include gender-neutral fields “parent giving birth” and “parent not giving birth,” with options for each role to specify “mother,” “father,” or “parent.” We classified birthing patients in mother-mother partnerships and those who identified as a father in any partnership as likely sexual and/or gender minority, and classified birthing patients in mother-father partnerships as likely not sexual and/or gender minority. We used multivariable modified Poisson regression models to estimate risk ratios for associations between likely sexual and/or gender minority parental structures and outcomes. Models were adjusted for sociodemographic factors, comorbidities, and multifetal gestation selected by causal diagrams. We replicated analyses after excluding multifetal gestations.

Results:

In the final birthing patient sample, 1,483,119 were mothers with father partners, 2,572 were mothers with mother partners, and 498 were fathers with any partner. Compared with birthing patients in mother-father partnerships, birthing patients in mother-mother partnerships experienced significantly higher rates of multifetal gestation (aRR 3.9, 95% CI 3.4-4.4), labor induction (aRR 1.2, 95% CI 1.1-1.3), postpartum hemorrhage (aRR 1.4, 95% CI 1.3-1.6), severe morbidity (aRR 1.4, 95% CI 1.2-1.8), and non-transfusion severe morbidity (aRR 1.4, 95% CI 1.1-1.9). Severe morbidity was identified following the Centers for Disease Control and Prevention “severe maternal morbidity” index. Gestational diabetes mellitus, hypertensive disorders of pregnancy, cesarean birth, preterm birth (<37 weeks’ gestation), low birthweight (<2,500 g), and low Apgar score (<7 at 5 minutes) did not significantly differ in multivariable analyses. No outcomes significantly differed between father birthing patients in any partnership and birthing patients in mother-father partnerships in either crude or multivariable analyses, although the risk of multifetal gestation was non-significantly higher (aRR 1.5, 95% CI 0.9-2.7). Adjusted risk ratios for outcomes were similar after restriction to singleton gestations.

Conclusions:

Birthing mothers with mother partners experienced disparities in several obstetric and birth outcomes, independent of sociodemographic factors, comorbidities, and multifetal gestation. Birthing fathers in any partnership were not at significantly elevated risk of any adverse obstetric or birth outcome considered in this study.