UNITED NATIONS — When Dr. Natalia Kanem visited a mobile maternal clinic in Syria’s war-ravaged city of Homs this year, she was struck by one patient’s cause of anxiety. It was not pregnancy.

“The first thing the woman wanted to know was, could I get the blood-pressure medication for her husband,” said Dr. Kanem, who leads the United Nations Population Fund, which runs the clinic. Before Dr. Kanem’s visit ended, she made sure the woman would get her husband’s medicine. “If this is what’s on her mind, we’ve got to accommodate it,” she said.

Dr. Kanem, 62, an Ivy League-educated physician and epidemiologist from Panama who has spent three decades working on public health issues in some of the world’s most deprived places, said the Homs anecdote helped to illustrate how the United Nations Population Fund, an agency known as UNFPA, does far more than its name might suggest.

With operations in 155 countries and territories, most notably the poorest, the fund is the world’s leading provider of family planning services, including contraception. It has sent contraceptives by drone to hard-to-reach parts of Africa. It has helped guide Mongolian midwives over the telephone.