Antimüllerian hormone rebound and estradiol changes in the study of women's health across the nation.

OBJECTIVE

To characterize the prevalence of redetectable antimüllerian hormone (AMH) over the menopause transition and correlation with other ovarian hormones indicating rebound in ovarian function.

DESIGN

Multisite prospective observational cohort study.

SUBJECTS: Participants in the Study of Women's Health Across the Nation (SWAN) with an observed final menstrual period (FMP) and three or more AMH measurements with at least one AMH measurement below the lower limit of detection.

EXPOSURE: Age at FMP, oligomenorrhea, body mass index, and time to FMP from AMH limit of detection.

MAIN OUTCOME MEASURES: The main outcome measures were AMH levels after becoming undetectable and estradiol (E2) change after undetectable AMH utilizing ultrasensitive assay. Secondary outcomes were follicle-stimulating hormone (FSH) and inhibin B hormone levels after the AMH limit of detection.

RESULTS

Of 1,558 participants with AMH data, 406 met the inclusion criteria. Of these, 220 (54.2%) had a subsequently detectable AMH after reaching the lower limit. Of women with AMH rebound, 107 (48.6%) also had a concurrent rise in E2. The AMH rebound was associated with younger age at the detectable limit of AMH (AMH+E2 48.5 years [SD 2.7], AMH only 49.9 [2.6], no rebound 51.7 [2.6]) lower body mass index (BMI) (AMH+E2 24.5 kg/m2 [interquartile range, IQR 21.6-30.9], AMH only 25.0 [22.4-31.8], no rebound 27.5 [IQR 23.5-34.6]), and a lower FSH at the AMH limit of detection (AMH+E2 28.6 mIU/mL [IQR 15.3-57.8], AMH only 29.8 [12.9-64.2], no rebound 62.5 [38.3-95.1]). There was no difference in the age at FMP (AMH+E2 52.2 years [SD 2.5], AMH only 52.3 [2.4], no rebound 52.8 [2.6]).

CONCLUSION

Almost half of the women in the SWAN AMH study demonstrated AMH rebound; in half of these cases, AMH rebound was followed by a rise in E2, implying that AMH rebound is reflective of recrudescence of ovarian activity. Younger age at reaching undetectable AMH, lower BMI, and lower FSH levels were associated with this finding. Clinicians should be aware that transient AMH and ovarian hormone levels may vary after becoming undetectable, with implications for perimenopausal staging.