Herbert Gladstone Hopwood Jr., 67, an Arlington obstetrician and gynecologist who delivered more than 10,000 babies during his career in Northern Virginia, died of cardiac arrest Oct. 31 at Arlington Hospital.

Dr. Hopwood, who had a solo practice in Arlington since settling there in the late 1960s, was past president of the Arlington County Medical Society and an active member of its subcommittees on sports health and health care for inmates. He was a recipient of the society's Welburn Award for outstanding service.

He was a Navy veteran, a writer of professional articles, a frequent lecturer on childbirth and a clinical assistant professor at Georgetown University.

The son of a four-star Navy admiral, he was born in Philadelphia and raised in a number of cities including Washington, where he attended Western High School.

Dr. Hopwood graduated from Franklin & Marshall College in Lancaster, Pa., and received a medical degree from what is now Thomas Jefferson University in Philadelphia.

While serving in the Navy from 1958 to 1968, he did an internship at Oakland Naval Hospital, then spent three years in obstetrics at Great Lakes Naval Hospital in Waukegan, Ill., before transferring to the Naval Medical Center in Bethesda as the assistant chief of the obstetrics department. He served 22 years in the Navy Reserve before retiring in 1990 with the rank of captain.

He was a past president of Arlington Rotary Club and a member of the South Atlantic Ob-Gyn Association.

Survivors include his wife of 41 years, Elizabeth Hopwood of Arlington; three children, Herbert Gladstone Hopwood III of Vienna, Elizabeth Jean Marty of Minneapolis and Matthew Alexander Hopwood of Olney; a brother; a sister; and five grandchildren.