Two-mom families have higher rates of birth complications

Mothers with partners who also identified as mothers had substantially higher rates of adverse pregnancy and birth outcomes, including life-threatening complications such as postpartum hemorrhage, than mothers with partners who identified as fathers, according to a study of nearly 1.5 million births in California.

Led by scientists at the Stanford University School of Medicine, the study published March 28 in the American Journal of Obstetrics and Gynecology. It is the first population-based study to investigate obstetric health among sexual and gender minorities in the United States.

We found that there is a diversity of parent structures in California, meaning different family constellations with different demographics and health outcomes."

Juno Obedin-Maliver, MD, MAS, MPH, study's senior author, assistant professor of obstetrics and gynecology at Stanford

Doctors need to pay attention to the health risks associated with giving birth as part of a nontraditional family, she added, because many of the risks, including elevated blood pressure, postpartum hemorrhage and twin pregnancies, could be addressed with better medical care.

There is a growing need to understand the reproductive health of sexual and gender minorities, Obedin-Maliver said. More young adults identify as being in these groups than in the past, and they are now more likely to build families by giving birth.

"The disparities faced by people who were mothers in partnership with a mother were striking," said lead author Stephanie Leonard, PhD, an instructor of obstetrics and gynecology Stanford. "The crude observed rates of postpartum hemorrhage were about double compared with people in mother-father partnerships, and after we adjusted for confounding factors, hemorrhage risk was still about 40% higher. That was more than I had expected."

Inclusive birth certificates

The study was enabled by a change to California's birth certificates. Since 2016, instead of asking for identifying information about the baby's mother and father, the forms request the "parent giving birth" and "parent not giving birth," allowing each role to be specified as "mother," "father" or "parent." The biological sex of the "parent not giving birth" is not provided on the certificate; neither is the gender identity of either parent. The new forms enable all parents to accurately report their family structures and establish legal parentage. Because California's birth certificate data is available for research purposes and is linked to electronic health records, the change also created opportunities to study the health of LGBTQ+ parents during pregnancy and birth.