10 powerful lesbian doctors: they've taken the Hippocratic Oath--or some modern version of it--and these lesbian doctors make it their business to lead the way in providing the best in research and medical care for the lesbian and transgender communities.(List)

1 CHRISTY ISLER

As an associate professor of perinatology and the residency program director in the Department of Obstetrics and Gynecology at East Carolina University's Brody School of Medicine in Greenville, N.C., Isler is a busy woman. "I see patients with complications, make prenatal diagnoses and detect birth defects and risks associated with problem pregnancies." Like all the doctors on this list, she is well-respected and considered one of the best out lesbian doctors in the business.

2 PATRICIA ROBERTSON

A perinatologist at the University of California at San Francisco, she specializes in high-risk pregnancy and is a member of the Fetal Treatment Center at UCSF Children's Hospital. She also made her mark in the annals of lesbian health by co-founding the Lyon-Martin Clinic, a center for lesbian health research in San Francisco 20 years ago. Robertson remembers that she was one of only a handful of women at her medical school. "As a female medical student in those days, you were basically seen as wasting their time or taking up space that could have been better used for a man."

3 NANETTE GARTRELL

A well-respected academic psychiatrist, she will soon be publishing a groundbreaking study about children of lesbians, the longest-running study of its kind, which began before the children were born and has been following a group of them for 21 years (nllfs.org). Gartrell is also a big name in lesbian-feminist medical ethics and has examined the issue of maintaining boundaries between therapists and their patients. Her new book, My Answer Is No ... If That's Okay with You: How Women Can Say No and (Still) Feel Good About It, includes quotes from female celebrities and politicians, CEOs and everyday women.

4 DEE MOSBACHER