Should blood samples be collected under fasting conditions for measurement of anti-Mullerian hormone (AMH) levels

Abstract

Measurement of anti-müllerian hormone (AMH) is used to assess ovarian reserve. Circulating levels of AMH are correlated with antral follicle count, with relatively high levels indicating an ample reserve of primary and pre-antral follicles in the ovary. A new, sensitive AMH assay has been introduced (ultrasensitive AMH, Ansh Labs, Webster, TX). Levels of AMH determined with this method are stable with dilution and freezer storage, and are not affected by hemolysis (Kumar A et al., Annual Meeting of the American Association for Clinical Chemistry, 2013). We sought to examine whether fasting influenced AMH levels. Analysis of AMH levels in stored samples originally collected from pregnant women under fasting conditions and after glucose intake. Residual plasma samples were collected from 18 pregnant women under fasting conditions and then 1, 2 and 3 hours after ingestion of a 100 gram glucose challenge as part of routine clinical care to identify gestational diabetes at 24-28 weeks of gestation. Four of these women met criteria for gestational diabetes based on an elevated glucose level (fasting > 95, 1 hour > 180, 2 hour > 155 and 3 hour > 140 mg/dL) at a minimum of two time points. Residual samples were collected with approval of the IRB at Women and Infants Hospital. Levels of AMH were measured using an ultrasensitive ELISA (Ansh Labs). AMH levels were compared before and at each hour after glucose ingestion using matched t-test analysis of log transformed values. One woman had AMH levels below the assay limit of detection (0.08 ng/mL) at all time points and was omitted from the analyses. For the remaining women, the median level of AMH in plasma under fasting conditions was 1.61 ng/mL (range 0.21 - 5.93). Median AMH levels were 1.39 ng/mL at 1 hour, 1.36 ng/ml at 2 hours and 1.45 ng/mL at 3 hours after ingestion of glucose. The average within-women reductions in fasting AMH levels were 6.7, 4.2 and 3.7% at 1, 2 and 3 hours after glucose. Only the reduction in AMH at 1 hour after gucose was significantly lower than the fasting level (95% CI, 0.4 - 17%). Removal of 4 women who met criteria for gestational diabetes after glucose testing did not alter the AMH results. Glucose ingestion had a small and transient suppressive effect on fasting plasma AMH levels in pregnant women. The effect of fasting on AMH levels has yet to be studied in non-pregnant women. Nevertheless, these preliminary data suggest that it may be preferable to draw samples for assessment of ovarian reserve under fasting conditions.