Infertile women below the age of 40 have similar anti-Müllerian hormone levels and antral follicle count compared with women of the same age with no history of infertility.

STUDY QUESTION Do infertile patients below the age of 40 years have a lower ovarian reserve, estimated by anti-Müllerian hormone (AMH) and total antral follicle count (AFC), than women of the same age with no history of infertility? SUMMARY ANSWER Serum AMH and AFC were not lower in infertile patients aged 20-39 years compared with a control group of the same age with no history of infertility. WHAT IS KNOWN ALREADY? : The management of patients with a low ovarian reserve and a poor response to controlled ovarian stimulation (COS) remains a challenge in assisted reproductive technologies (ART). Both AMH levels and AFC reflect the ovarian reserve and are valuable predictors of the ovarian response to exogenous gonadotrophins. However, there is a large inter-individual variation in the age-related depletion of the ovarian reserve and a broad variability in the levels of AMH and AFC compatible with conception. Women with an early depletion of the ovarian reserve may experience infertility as a consequence of postponement of childbearing. Thus, low ovarian reserve is considered to be overrepresented among infertile patients. STUDY DESIGN, SIZE, DURATION A prospective cohort study including 382 women with a male partner referred to fertility treatment at Rigshospitalet, Copenhagen, Denmark during 2011-2013 compared with a control group of 350 non-users of hormonal contraception with no history of infertility recruited during 2008-2010. PARTICIPANTS/MATERIALS, SETTING, METHODS Included patients and controls were aged 20-39 years. Women with polycystic ovary syndrome were excluded. On Cycle Days 2-5, AFC and ovarian volume were measured by transvaginal sonography, and serum levels of AMH, FSH and LH were assessed. MAIN RESULTS AND THE ROLE OF CHANCE Infertile patients had similar AMH levels (11%, 95% confidence interval (CI): -1;24%) and AFC (1%, 95% CI: -7;8%) compared with controls with no history of infertility in an age-adjusted linear regression analysis. The prevalence of very low AMH levels (<5 pmol/l) was similar in the two cohorts (age-adjusted odds ratio: 0.9, 95% CI: 0.5;1.7). The findings persisted after adjustment for smoking status, body mass index, gestational age at birth, previous conception and chronic disease in addition to age. LIMITATIONS, REASON FOR CAUTION The comparison of ovarian reserve parameters in women recruited at different time intervals could be a reason for caution. However, all women were examined at the same centre using the same sonographic algorithm and AMH immunoassay. WIDER IMPLICATIONS OF THE FINDINGS This study indicates that the frequent observation of patients with a poor response to COS in ART may not be due to an overrepresentation of women with an early depletion of the ovarian reserve but rather a result of the expected age-related decline in fertility. STUDY FUNDING/COMPETING INTERESTS The study received funding from MSD and the Interregional European Union (EU) projects 'ReproSund' and 'ReproHigh'. The authors have no conflict of interest. TRIAL REGISTRATION NUMBER Not applicable.