Smoking, alcohol and caffeine in relation to ovarian age during the reproductive years.

Background: We sought to determine whether smoking, alcohol and caffeine are related to four indicators of ovarian age: antral follicle count (AFC), follicle stimulating hormone (FSH), inhibin B and estradiol.

Methods: Analyses drew on ultrasound scans and sera from 188 women, aged 22-49. We used least squares regression to estimate differences in AFC and hormone levels for women who smoke cigarettes or who drink alcohol or caffeine.

Results: Current smoking is related to elevated FSH (beta for ln(FSH) = 0.21, 95% CI 0.04, 0.39), but not to AFC, inhibin B or estradiol. Neither alcohol nor caffeine is related to any ovarian age indicator. Exploratory analyses suggest that the association of current smoking with FSH varies with age: comparing current with never smokers, at ages 30, 35, 40 and 45, estimated differences in mean FSH are 0.3, 1.3, 3.2 and 6.9 mIU/ml.

Conclusions: The association of current smoking with FSH may reflect accelerated oocyte atresia, impaired follicle quality or dysregulation of the hypothalamic-pituitary-ovarian axis. Identification of the causal mechanism has implications for prevention or treatment of conception delay, infertility and morbidity associated with early menopause.