Objective: Smoking is associated with increased follicle-stimulating hormone levels and early menopause. Smoking may directly accelerate ovarian follicular depletion or may act indirectly by increasing the pituitary production of follicle-stimulating hormone. Antimüllerian hormone (AMH), produced by ovarian follicles, is a more direct measure of ovarian reserve. The objective of our study was to determine the extent to which smoking influences ovarian reserve, as measured by AMH levels.
Methods: A community sample of 284 women aged 38 to 50 years completed a self-administered questionnaire including a detailed smoking history. Serum AMH levels were measured on day 2, 3, or 4 of the menstrual cycle. The association between AMH and smoking was analyzed using linear regression, adjusting for age and body mass index.
Results: Participants aged 38 to 42, 43 to 45, and 46 to 50 years had geometric mean AMH values of 6.7 pM (95% CI, 5.2-8.7 pM), 2.7 pM (95% CI, 1.9-3.8 pM), and 1.3 pM (95% CI, 1.0-1.7 pM), respectively. Current smokers, but not past smokers, had 44% lower AMH values than did the reference group (participants with neither active nor former or passive smoke exposure; P = 0.04). Passive smoking had no effect on AMH values when compared with the reference group (P = 0.55). The impact of smoking on AMH values was not dose dependent based on cigarettes per day (P = 0.08) or pack-years (P = 0.22). Finally, prenatal exposure to smoking (either maternal or paternal) had no impact on AMH levels (P = 0.47 and P = 0.89, respectively).
Conclusions: Active smoking, but not former smoking, is associated with decreased AMH values in late-reproductive-age and perimenopausal women, suggesting a possible direct effect of smoking on the depletion of the antral but not primordial follicles. The direct impact of active smoking on AMH levels in younger women requires further investigation.