USE OF URINE BIOMARKERS TO EVALUATE MENSTRUAL FUNCTION IN HEALTHY PREMENOPAUSAL WOMEN

A total of 403 healthy, premenopausal women, residing near Santa Clara , California, were recruited from a large health care plan in Californ ia for a study of menstrual function. After a telephone interview, par ticipants collected daily urine samples and recorded bleeding and othe r information in diaries. Data were collected during 1990-1991, Urine samples were analyzed for creatinine and for estradiol and progesteron e metabolites by enzyme-linked immunoassay. Computer algorithms were d eveloped to derive menstrual segment length, ovulatory status, day of ovulation, and other parameters from the urine and diary data. (We use ''segment'' rather than ''cycle'' to avoid implying that normal cycli ng occurred.) The average length of participation was 141 (standard de viation, 45) days. The mean segment length was 28.8 (standard deviatio n, 4.4) days; follicular phase length, 16.0 (standard deviation, 4.4) days; and luteal phase length, 12.9 (standard deviation, 1.7) days; 19 (4.7%) women experienced anovulatory episodes. In exploratory multiva riate analyses, important associations included the following: age of greater than or equal to 35 years with decreased segment and follicula r phase lengths; heavier weight (upper quartile) with anovulation and increased follicular phase and decreased luteal phase lengths; Hispani c ethnicity with anovulation and increased segment length; and past di fficulty in achieving pregnancy with anovulation and increased length and variability of segments and follicular phases. Urine biomarkers ca n be used successfully to evaluate menstrual function in epidemiologic studies.