Sexual and/or gender minority parental structures among California births from 2016 to 2020

Sexual and/or gender minority people account for roughly 7.1% of the US population, and an estimated one-third are parents. Little is known about sexual and/or gender minority people who become pregnant, despite this population having documented healthcare disparities that may affect pregnancy.

Our objective was to describe parental structures among birth parents and the prepregnancy characteristics of parents giving birth in likely sexual and/or gender minority parental structures from California birth certificates.

We conducted a population-based study using birth certificate data from all live births in California from 2016 through 2020 (n=2,257,974). The state amended its birth certificate in 2016 to enable the recording of more diverse parental roles. Now, parents on birth certificates are classified as "parent giving birth" and "parent not giving birth" and people in either role can identify as "mother," "father," or "parent." We examined all potential combinations of parenting roles, and grouped parental structures of "mother-mother" and those designating a "father" as the "parent giving birth" into likely sexual and/or gender minority groups. We assessed the distribution of prepregnancy characteristics across parental structure groups ("mother-father," "sexual and/or gender minority," "mother only," "unclassified," and "missing both parental roles").

Sexual and/or gender minority parents accounted for 6802 (0.3%) of live births in California over the 5-year study period. The most common sexual and/or gender minority parental structures were "mother-mother" (n=4310; 63% of the group) and "father-father" (n=1486; 22% of the group). Compared with "parents giving birth" in the "mother-father" structure (n=2,055,038; 91%), a higher proportion of "parents giving birth" in the "sexual and/or gender minority" group were aged ≥35 years, White, college-educated, and had commercial health insurance. In addition, a higher proportion had a high prepregnancy body mass index. Although likely underreported overall, the proportion of those who used assisted reproductive technology was much higher in the "sexual and/or gender minority" group (1.4%) than in the "mother-father" group (0.05%). Cigarette smoking in the 3 months before pregnancy was similar in both groups.

Changes to the California birth certificate have revealed a multiplicity of parental structures. Our findings suggest that sexual and/or gender minority parents differ from other parental structures and from the general sexual and/or gender minority population and warrant further research.