Changes in the Numbers of Male and Female Obstetricians-Gynecologists and Their Implications.

Over the last 50 years, the percentage of women in medicine has more than doubled. Every medical specialty now has a critical mass of females, defined as ≥15%, and 6 specialties have greater than 50% women. Obstetrics and gynecology (OB/GYN) has undergone an almost complete reversal of the gender makeup of the specialty and soon will have less than a critical mass of men. Certain gender-based inequities persist despite OB/GYN being majority female since 2008. Moving forward, the specialty must continue supporting women's advancement to leadership positions and recruiting male medical students to OB/GYN residency.