Katharina Dalton, 87, a gynecologist who did pioneering research on premenstrual syndrome and was said to have coined the term, died Sept. 17 in Poole, England. No cause of death was reported.

Born Katharina Kuipers in London to Dutch parents, she aspired to be a doctor. She became a podiatrist first, trained to treat foot ailments.

After her first husband, Wilfred Thompson, died in World War II, she went to medical school and eventually became a general practitioner before specializing in gynecology, the Independent newspaper in London reported in an obituary.

Later, she began a research career, publishing pioneering studies on PMS. She introduced the idea of treating PMS with the hormone progesterone, which she found alleviated many symptoms.

Dr. Dalton also believed the hormone might be useful in treating postnatal depression.

She ran the PMS clinic at London's University College Hospital, which was among the first of its kind in the world.

Many of her books posted big sales internationally, including "Once a Month: The Original Premenstrual Syndrome Handbook" (1978) and "Depression After Childbirth: How to Recognize, Treat, and Prevent Postnatal Depression."

Her second husband, Tom Dalton, died in 1992.

Survivors include a son from the first marriage; three children from the second marriage; and five grandchildren.