Our Doctors


Dr. Padma Tummala

Dr. Padma Tummala has been recognized as a fellow by the American College of OB/GYN. She received her MBBS degree in New Delhi, India at Lady Harding Medical College where she pursued her MD Post studies in OB/GYN training. She did a transitional internship at Oakwood Hospital in Dearborn, Michigan. Dr. Tummala did her residency in Obstetrics and Gynecology at Temple University in Philadelphia, Pennsylvania. She joined Park Avenue Obstetrics and Gynecology in August, 1993. She is board certified and provides comprehensive Gyn care including gynourology, advanced laparoscopy and robot, in office procedures. Dr.Tummala is married and has a son and a daughter. Her hobbies include yoga, reading, and cooking.


Dr. David Chisholm


was born and raised in Illinois and moved to Phoenix, Arizona in 1986. He attended Arizona State University and received a bachelor in Psychology. Dr. Chisholm attended Midwestern University and graduated in 2001. He completed his residency in Obstetrics and Gynecology at the University of Illinois and University of Arizona. He joined Park Avenue OB/GYN in October 2007 and is board certified. Dr. Chisholm is a member of the Maricopa Medical Society and Arizona Medical Association. He is a family man and his interests include fishing, golfing, and camping with his family. Dr. Chisholm also offers vaginal rejuvenation procedures.

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Terri Hahn


acquired her associates degree as a Registered Nurse from Glendale Community College in 1983. She worked full time as an RN in Women and Infant Services at Maryvale Samaritan Medical Center until 1988 when she began working with Dr. Brown. In 1994, she received her Nurse Practitioner certificate at the University of Phoenix and received here national certification. She is a native Arizonan and grew up in San Manuel, a small mining town north of Tucson. She moved to the valley in 1975 and is a mom to three adult children. She is an educational affiliate of ACOG. Her special interests are family activities, baking, and cooking. 

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Dr. Mary-Helene Brown

****After 30 years of OB/GYN services as a provider at Park Avenue OB/GYN, Dr. Mary-Helene Brown has retired effective August 1, 2016. ****

Dr. Mary-Helene Brown started Park Avenue OB/GYN in Phoenix, Arizona in August, 1986. She graduated Cum Laude and Phi Beta Kappa from Kalamazoo College. She earned her medical degree from Wayne State University in 1979, followed by an internship and residency in Obstetrics and Gynecology at Oakwood Hospital in Dearborn, Michigan from 1979 to 1983. She was with the United States Public Health Service in Detroit, Michigan for two years and was formerly a staff physician in Obstetrics and Gynecology with the Cigna Health Plan of Arizona until July, 1986. Dr. Brown was board certified in 1985 and recertified in 1995. She is a fellow of the American College of Obstetrics and Gynecology and a member of the Arizona Medical Association, the Maricopa County Medical Society and the Phoenix OB/GYN Society. Her special interests include golf, raising champion Dobermans and gourmet cooking. Dr. Brown is also an AKC judge of Dobermans, Boxers, and Portuguese Water Dogs.