A menstrual history was taken from the female partners of all new
infertility couples seen in our clinic between 1988 and 1990. The body mass index (Kg/M2) was measured in all females. The ovulatory status was studied using a combination of serial transvaginal ultrasound investigations and
progesterone measurements in the second half of the cycle in females with regular menstrual cycles or
progesterone measurements one week before the expected onset of menstruation in females with
oligomenorrhea. Amenorrheic patients were considered anovulatory if no anatomical abnormality was found. Out of the 1755 patients, only 17% were in the normal weight category (BMI 19-24), 42% were
overweight (BMI25-29) and 38% were obese (BMI 30 or more), while the remaining 3% were underweight. With increasing BMI, the percentage of
oligomenorrhea increased from 18% to 32%, the percentage of
amenorrhea increased from 2% to 13%. The overall percentage of
anovulation increased from 32% to 55%.