Mary E. Norton is a perinatologist and clinical geneticist at UCSF Medical Center's Prenatal Diagnostic Center. She primarily cares for pregnant women who have a fetus with a birth defect or genetic disorder or are at risk for such a condition. Norton performs obstetrical ultrasounds, counsels women in whom ultrasound detects a problem with the fetus and performs such prenatal tests as amniocentesis and chorionic villus sampling. She also interprets complex genetic tests, especially when abnormalities are found. Her areas of interest in research include applying new genetic tests to prenatal diagnosis and fetal disease, as well as patient decision-making around genetic testing and obstetrical ultrasound. She is also the chair of the obstetrics, gynecology and reproductive sciences at UCSF.

Norton earned her undergraduate degree at the University of Washington in 1982. She completed her internship and residency in Obstetrics and Gynecology at Tuft University in Boston in 1990. She completed a fellowship in Maternal Fetal Medicine and Clinical Genetics at UCSF in 1993. After several years at Brigham and Women's Hospital and Harvard Medical School, she returned to San Francisco where she joined UCSF Medical Center in 1998. She is a professor of obstetrics, gynecology and reproductive sciences at UCSF.