University Park, Pa. -- An in-depth databank of information about the menstrual cycles of more than 6,000 American women over the past 65 years, known as The Tremin Trust, now resides at Penn State and is available to women's health researchers nationally and globally.
Originally called the Menstruation and Reproductive History Program, the project was started in the early 1930s by health researcher Alan Treloar of the University of Minnesota, who enrolled local co-eds. Prior to this project, little research had been done on women's menstrual health, according to current Trust director Dr. Phyllis Kernoff Mansfield, professor of women's studies and health education at Penn State.
"Treloar's classic research, published in 1967, served to establish that a wide band of variability is normal in women's menstrual cycles," said Kernoff Mansfield. "His study showed that at the beginning of a woman's reproductive life and the end, periods are most erratic in timing and duration."
The Trust data contains in-depth information about the entire menstrual lives of more than 6,000 women from their 20s up until menopause. Each year, the participants record the first and last day of each monthly period, and annually or biannually complete a health survey form listing events that might have affected their menstrual cycles such as pregnancies, births, miscarriages, surgeries, or birth control. Since 1990, they also have recorded how much menstrual bleeding occurs on a cycle day, using a scale developed by Kernoff Mansfield and Dr. Ann Voda, the Trust's second director, from the University of Utah.
Today, the Trust's intergenerational data includes information on women from age 11 to 105. There are 653 families, 555 with two generations, 95 with three generations and three with four generations. The participants also include 184 pairs of sisters, 50 sets of three sisters, 15 sets of four sisters and 2 sets of five sisters. There are also five sets of twins. A significant number of the Trust participants are Minnesotans, predominantly Scandinavian.
In 1964, as the first group of participants reached their 50s, original director Treloar recruited a second group from the University of Minnesota. He also routinely invited participants' daughters, granddaughters and great-granddaughters to join the project.
"The beauty of the second cohort is that as menopause became more interesting to researchers, these women were entering menopause," says Kernoff Mansfield.
After Treloar's retirement in 1984, the project was renamed The Tremin Trust and was moved to the University of Utah under Dr. Ann Voda's leadership. When she retired in 1998, the Trust transferred to Dr. Kernoff Mansfield, who became only the third director.
The 44 cartons of data and administration files and 15 file cabinets of women's data as well as all the computerized records that make up The Tremin Trust found a physical home in Penn State's Population Research Institute, where Kernoff Mansfield is a research associate. Major support of the Tremin Trust comes from Penn State's College of the Liberal Arts and PRI, which conducts interdisciplinary population research and training.
Currently, women in the Tremin Trust are providing information to a long-standing Midlife Women's Health Survey conducted by Kernoff Mansfield and Voda and to another federally funded study, BIMORA, "Biodemographic Models of Reproductive Aging." The BIMORA study, based at the Population Research Institute, Penn State's College of the Liberal Arts and the University of Washington, is investigating hormonal changes that occur during the menopausal transition. BIMORA is measuring estrogen and progesterone from first morning urine samples. To this end, approximately 150 of the Tremin Trust women provide daily urine samples for six months out of every year for five years.
"We are so fortunate to be able to preserve and extend this valuable source of information on women's menstrual lives and reproductive health. So many women today are taking hormones either for birth control or for postmenopausal symptoms that doing this type of study again may never be possible. It is becoming nearly impossible to depict the natural course of menopause. We look forward to working with qualified researchers in utilizing this rich data set and encourage inquiries from colleagues."
EDITORS: Dr. Mansfield may be reached at 814-863-0356 or pkm@psu.edu.