Extended fertility at highly advanced reproductive age is not related to anti-Müllerian hormone concentrations

Research question: Is extended fertility at the advanced reproductive age of 43-47 years associated with high anti-Müllerian hormone (AMH) concentrations?

Design: Prospective cohort study including 98 women aged 43-47 years old with a spontaneous conception who were tested for AMH concentrations 1-4 days and 3-11 months post-partum. AMH concentrations at 3-11 months post-partum were further compared with AMH concentrations in healthy age-matched controls that last gave birth at ≤42 years old. Women with current use of combined hormonal contraceptives (CHC), ovarian insult or polycystic ovary syndrome were excluded. Power analysis supported the number of participating women.

Results: Median AMH concentrations did not differ between the extended fertility (n = 40) and control (n = 58) groups (0.50 versus 0.45 ng/ml, P = 0.51). This remained when analysing by age (≥ or <45 years old). AMH concentrations and women's age did not correlate within the extended fertility group (r = 0.017, P = 0.92); a weak negative correlation was found within the control group (r = -0.23, P = 0.08). AMH was significantly higher 3-11 months post-partum (0.50 ng/ml [0.21-1.23]) than 1-4 days post-partum (0.18 ng/ml [0.06-0.40]), P < 0.001. The two results for each participant were highly correlated (r = 0.82, P < 0.001). The extended fertility and control groups were similar regarding age, age at menarche, past CHC use and history of fertility concern. Parity differed but showed no significant correlation with AMH.

Conclusions: Serum AMH concentrations that reflect ovarian reserve do not seem to predict reproductive potential at highly advanced age. Thus, additional factors such as oocyte quality should also be considered in evaluating reproductive potential. AMH suppression that is associated with pregnancy at 1-4 days post-partum recovers at 3-11 months post-partum in women of highly advanced reproductive age.