Factors affecting the distribution of serum anti-mullerian hormone levels among infertile Asian women: a multi-nation, multi-centre, and multi-ethnicity prospective cohort study

STUDY QUESTION How do age, ethnicity, and other characteristics affect serum anti-mullerian hormone (AMH) levels in Asian women undergoing fertility treatment? SUMMARY ANSWER Age, ethnicity, obesity (BMI >= 30 kg/m(2)), and polycystic ovarian syndrome (PCOS) significantly impacted serum AMH levels, with the rate of decrease accelerating as age increased; a concentration of 4.0 ng/ml was the optimal cut-off for diagnosis of PCOS. WHAT IS KNOWN ALREADY There are significant differences in ovarian reserve among women from different races and ethnicities, and Asian women often have poorer reproductive outcomes during assisted reproductive treatment cycles. STUDY DESIGN, SIZE, DURATION A population-based multi-nation, multi-centre, multi-ethnicity prospective cohort study of 4613 women was conducted from January 2020 to May 2021. Infertile women of 20-43 years of age were enrolled. The exclusion criteria included: age 43, non-Asian ethnicity, and missing critical data. PARTICIPANTS/MATERIALS, SETTING, METHODS Participants were Asian women of Chinese, Japanese, Korean, Thai, Vietnamese, Malay, Indian, and Indonesian ethnicities from 12 IVF centres across Asia. These women were all naive to ovarian stimulation cycles and attended IVF centres for fertility assessment. The AMH measurement was performed using an AMH automated assay on a clinically validated platform. MAIN RESULTS AND THE ROLE OF CHANCE A total of 4556 infertile Asian women were included in the final analyses. The mean +/- SD for serum AMH concentrations (ng/ml) across specific age groups were: overall, 3.44 +/- 2.93; age <30, 4.58 +/- 3.16; 30-31, 4.23 +/- 3.23; 32-33, 3.90 +/- 3.06; 34-35, 3.21 +/- 2.65; 36-37, 2.74 +/- 2.44; 38-39, 2.30 +/- 1.91; 40 and above, 1.67 +/- 2.00. The rate of AMH decrease was similar to 0.13 ng/ml/year in patients aged 25-33 and 0.31 ng/ml/year in women aged 33-43. The highest rates of PCOS were found in Indians (18.6%), Malays (18.9%), and Vietnamese (17.7%). Age (P < 0.001), ethnicity (P < 0.001), obesity (P = 0.007), PCOS (P < 0.001), and a history of endometrioma cystectomy (P = 0.01) were significantly associated with serum AMH values. Smoking status, pretreatment with GnRH agonist (GnRHa) or the oral contraceptive pill (OCP), freezing-thawing of blood samples, and sampling on Day 2 to Day 5 of the menstrual cycle or randomly did not appear to affect serum AMH levels. An AMH concentration of 4.0 ng/ml was the optimal cut-off for PCOS diagnosis with a sensitivity of 71.7% and specificity of 75.8% (AUC = 0.81, CI 95%: 0.79-0.83; P < 0.001). LIMITATIONS, REASONS FOR CAUTION The incidence of PCOS was supposedly high in this cohort as some IVF clinics were tertiary referral centres for managing specific fertility issues encountered by women with PCOS. Treatment with GnRHa or OCP before AMH testing was regionally and ethnically confined, mostly in Hong Kong SAR and Japan. Moreover, this reference for serum AMH value is limited to Asian women of the ethnicities examined and may not apply to other ethnicities not included in the study. WIDER IMPLICATIONS OF THE FINDINGS This is the first study to collate and construct age-specific reference ranges for serum AMH levels using the same bioassay on Asian women of different ethnicities. The findings of this investigation can assist clinicians to counsel and prognosticate about Asian women's ovarian reserve and reproductive potential, thus providing better strategies for personalized fertility interventions. STUDY FUNDING/COMPETING INTEREST(S) This study was technically supported by Ferring Pharmaceuticals and received no specific grant from any funding agency. All authors have no competing interests to disclose.