Going through menopause may involve longer and heavier bleeding than previously thought, according to a new study that is among the first to examine normal symptoms of menopause.
“We really wanted to map out what can women expect,” said Sybil Crawford, a statistician at the University of Massachusetts Medical School who worked on the study.
More than three-quarters of the 1,300 women in the study, conducted with researchers at the University of Michigan, had periods lasting 10 or more days, two-thirds experienced spotting for six or more days a month, and more than one-third had at least three days of heavy bleeding.
Crawford said she hopes the study, published in the current issue of BJOG: An International Journal of Obstetrics and Gynaecology, will reassure women and their doctors.
Many middle-aged women often visit their doctors because of heavy bleeding, and such visits can lead to hysterectomies. Instead, doctors should consider that the heavy bleeding might be a normal part of the menopausal transition, Crawford said.
The menopausal transition generally starts in the early- to mid-40s and can last a decade, with a wide range of normal experiences, she said. Hot flashes occur most commonly at the peak of menopause, around age 51 or 52, she said. Most doctors assume they usually last just a few years, she said, but her research suggests that five years may be more typical.
The study also found differences by race. African-American women were more likely to have episodes of heavy bleeding, but less likely to have prolonged bleeding, Crawford said; Japanese and Chinese women were less likely to report heavy bleeding. The differences may be explained by weight, she said.
The study was conducted at seven sites across the United States, including Massachusetts General Hospital. The 1,320 volunteers kept daily menstrual calendars from 1996 -- when they were in their early- to mid-40s -- until 2006.