Adverse pregnancy and birth outcomes in sexual minority women from the National Survey of Family Growth.

backgroundFew studies have examined how multiple marginalized identities are associated with adverse pregnancy and birth outcomes, especially for Black and Hispanic sexual minority women. Sexual minorities are people who identify as lesbian, gay, bisexual or transgender (LGBT). The purpose of this study was to examine differences in adverse pregnancy (i.e., miscarriage) and birth outcomes (i.e., preterm birth, low birthweight, and stillbirth) in a national sample of women by race and ethnicity, and sexual minority status (LGBT identification and same-sex sexual behavior).

methodsWe conducted a cross-sectional analysis of the National Survey of Family Growth (NSFG). The unit of analysis was pregnancy, not participants. In this study, we examined pregnancies to participants who identified as heterosexual, lesbian, and bisexual, by race and Hispanic ethnicity. We also studied sexual behaviors to categorize participants as women who have sex with women (WSW) and women who have sex with men (WSM). Outcomes included preterm birth, low birthweight, miscarriage, and stillbirth. We employed logistic and linear regression analyses for analyses using STATA.

resultsWe studied 53,751 pregnancies, and 9% of these occurred in people who identified as heterosexual, but had engaged in sexual activity with a female partner (heterosexual-WSW), 7% in those identifying as bisexual, and 1% to women who identified as lesbian. Pregnancies ended in preterm birth (10.7%) and low birthweight (9.0%), stillbirths (2-4%), and miscarriages (17-21%) in sexual minority women. We observed that pregnancies reported by Hispanic lesbian women had a higher birthweight (β = 10.71, SE = 4.1, p-value = 0.01) compared to infants born to Hispanic heterosexual-WSM. Pregnancies to lesbian women were significantly more likely to end in stillbirth (aRR = 3.58, 95% CI 1.30,9.79) compared to heterosexual-WSM. No significant differences were noted in risk of adverse birth outcomes by sexual orientation for NH Black or Hispanic women.

conclusionIn this sample, preterm births were less likely to occur among heterosexual-WSW than in heterosexual-WSM. Pregnancies to lesbians and bisexual women were more likely to end in miscarriage or stillbirth than heterosexual WSM. Lesbian Hispanic women reported higher birthweights compared to heterosexual-WSM Hispanic women. More research should be done to further understand these findings.