De Dinh Tran, 86, the former health minister of the Republic of Vietnam who had a private practice in obstetrics-gynecology and acupuncture in Falls Church from 1975 until 1994, died March 20 at Northern Virginia Community Hospital. He had pneumonia.

Dr. Tran, a Falls Church resident, came to the United States in 1969 and became a U.S. citizen in the early 1970s when he was on the OB-GYN faculty of the Medical College of Virginia in Richmond.

In the late 1970s, he was a consultant in sonography for Howard University medical school's OB-GYN department. He co-developed the Ultra-Sono-Wheel, an early pocket-size rapid-reference tool for assessing fetal development through ultrasound.

Dr. Tran, whose father was a ranking official to Vietnamese emperor Bao Dai, was born in Hue, Vietnam. After graduating from medical school in Hanoi, he did postgraduate OB-GYN training in Vietnam, France and the United States, where he studied under George Papanicolaou, the doctor for whom the Pap smear, for cervical cancer detection, is named.

Dr. Tran then returned to Vietnam, where he became OB-GYN chairman at the Faculty of Medicine in Saigon and health minister. In those jobs, he was known for promoting women in medicine, helping to set up modern public health initiatives and starting programs to send health technicians to rural villages.

In 1966, he joined the World Health Organization in western Africa as a consultant in medical education.

He was founder and first president of the Vietnamese Medical Society of the northeastern United States.

Survivors include his wife of 60 years, Ngoc-Anh Dang Tran of Falls Church; a daughter, Dr. Ngoc D. Tran of Rockville; four sons, Dr. Hoa D. Tran, an Air Force lieutenant colonel, of O'Fallon, Ill., Dr. Chi D. Tran of Piedmont, Calif., Dr. Huyen D. Tran of Wynnewood, Pa., and Hy D. Tran of Albuquerque; three brothers; a sister; and 13 grandchildren.