Women with same-sex partners form biological and genetic families in myriad ways, including through using medically assisted reproduction (MAR)

MAR encompasses both assisted reproductive technology (ART) and non-ART MAR

Little is known about this population's utilization of MAR, including their unique reproductive care needs

Data from Growing Up Today Study (GUTS)

• Longitudinal cohort based in the U.S. (n = 27,805)

• 9 – 16 years of age at baseline (1996 initial enrollment)

• Biennial follow-up is ongoing

Eligibility: same- or different-sex partnered cisgender women

Methodological innovation

• Complex coding scheme identified MAR procedures and conception pathways relevant to same-sex couples

Analysis performed using RStudio and SAS 9.4

• Modified poisson models assessed MAR utilization and procedure type and generalized estimating equations accounted for participant clustering

Among 11,894 pregnancies reported in GUTS, eligible pregnancies / participants included:

• 6,683 unique pregnancies / pregnancy attempts among 3,441 participants

Participants with same- versus different-sex partners had a higher prevalence of identifying as

• Single (9.7 vs 5.0%)

• Non-Latina/Hispanic (93.5 vs 79.4%)

• A lesbian (66.0% vs 0.0%) or bisexual woman (23.4 vs 0.9%)

• Employed (90.3% vs 83.6%)

• Experiencing fewer lifetime pregnancies (29.0 vs 49.9%)

Higher proportion of pregnancies among same- versus different-sex partners used MAR for conception pathway (100.0% vs 18.7%; inclusive of our IVI/ICI pathway) and conceived at advanced maternal age (36.2% vs 14.0%)

Conception pathways significantly differed (x2 [7, N = 420] = 129, p = <0.0001) between groups among first pregnancies conceived using MAR

Pregnancies were conceived more frequently among

• intrauterine insemination (50.0 vs 21.1%)

• intravaginal / intracervical insemination (27.8 vs 0.0%)

• in vitro fertilization (11.1 vs 8.0%)

and less frequently using:

• ovulation medications (0.0 vs 30.8%)

Different conception pathways and a wider variety of non-ART MAR procedures are being used among same- vs different-sex women to achieve parenthood

Multilevel factors may driving these trends:

• Individual (e.g., social vs physiological infertility)

• Cultural (e.g., desiring less medicalized care)

• Structural (e.g., access to insurance coverage / care)

Heteronormative assumptions exclude important conception pathways and needs among same-sex partnered women

Epidemiologists need to include robust, precise, and repeated measures of sexual identity data to improve knowledge of potential disparities in ART access and utilization

First study using a national sample to elucidate family formation pathways unique to women with same-sex partners

Conception pathway assumptions may not be accurate and survey skip logics excluded certain participants

GUTS is majority White and educated with significant attrition over time (72.4% by 2019); participants are still experiencing prime reproductive years (youngest was 27 years old in 2021)