Anti-Mullerian Hormone (AMH) Levels are Reduced by Age, but do not Correlate with Pregnancy in Timed-Mated Rhesus Monkey Females (Macaca mulatta)

Abstract

Background: Evaluation of reproductive hormones is a common tool used to predict a patient's prognosis for fertility therapies. Specifically, anti-mullerian hormone (AMH) and activin A are two ovarian hormones which may be associated with follicle quality, yet their predictive ability to determine pregnancy outcomes are still not well characterized in primates. Objective: To use rhesus macaque as a well-characterized nonhuman primate model to assess the predictive power of AMH and activin A to determine pregnancy outcomes. Methods: Female rhesus macaques (n = 47) were monitored during timed breeding protocols beginning around day seven post menses until serum estradiol levels indicated ovulation was imminent. Females were then pair-housed with fertile male monkeys (Timed-Mated Breeding; TMB). Females were re-paired with males until the end of the breeding season if they failed to become pregnant. The first blood sample collected (days range 5-15) was analyzed for serum levels of AMH and activin A (n = 90). Pregnancy status was determined via ultrasound (Pregnant cycles n = 28, non-pregnant cycles n = 62). Mean age of females was 13 years (range: 6.3-17.7 years old), and mean weight was 7.35 kg (range: 5.35-10 kg). Results: There was no significant difference between AMH levels by pregnancy status (p > 0.4). Similarly, there was no significant difference between activin A levels by pregnancy status (p > 0.2). However, similar to data in women, negative correlations between age and AMH (R = -0.32, p = 0.002), and between weight and AMH (R = -0.22, p = 0.036) were detected. Conclusions: These data demonstrate that the predictive ability of AMH to determine reproductive success in primates is poor in a “natural” or unstimulated mating scenario. In addition, serum levels of activin A are not a reliable predictor of pregnancy success.