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.

Rapid estrogen effects are mediated by membrane receptors, and evidence suggests a role for both a membrane-associated form of estrogen receptor alpha (ESR1; ERα) and G-protein coupled receptor 30 (GPER; GPR30). Considering estrogen's importance in endometrial physiology and endometriosis pathophysiology, we hypothesized that GPER could be involved in both cyclic changes in endometrial estrogen action and that aberrant expression might be seen in the eutopic endometrium of women with endometriosis. Using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemical analysis of normal endometrium, endometrial samples demonstrated cycle-regulated expression of GPER, with maximal expression in the proliferative phase. Eutopic and ectopic endometrium from women with endometriosis overexpressed GPER as compared to eutopic endometrium of normal participants. Ishikawa cells, an adenocarcinoma cell line, expressed GPER, with increased expression upon treatment with estrogen or an ESR1 agonist, but not with a GPER-specific agonist. Decreased expression was seen in Ishikawa cells stably transfected with progesterone receptor A. Together, these data suggest that normal endometrial GPER expression is cyclic and regulated by nuclear estrogen and progesterone receptors, while expression is dysregulated in endometriosis.