Endocrine Abstracts

Introduction: In children undergoing investigation of testicular function the relationship between serum anti-Müllerian hormone (AMH) and the testosterone response to hCG stimulation test (HST) is unclear.

Methods: 71 children (three females and 68 males) with a median age of 1.08 years (range: 0.003, 14.3) were investigated for suspected DSD by AMH on D1 and testosterone on D1 and D4, before and after 3-day HST. Of these children, 27 had an additional prolonged HST. Normal testosterone response to HST was defined as a testosterone greater than upper prepubertal limit or a testosterone increment (ΔT) greater than twice the baseline value. A low AMH was defined as below the 5th centile for age.

Results: The D4 testosterone response was normal in 61 with a median testosterone of 9.4 nmol/l (1.0, 40.7) and a median ΔT of 11.1 (0.8, 59.2) and abnormal in ten with a median testosterone of 0.55 nmol/l (0.5, 3.0) and a median ΔT of 1.0 (0.7, 1.8). AMH was low in 12/71 children and in 5 (42%) of these cases a low D4 testosterone was observed. An AMH >5th centile was associated with a low D4 testosterone in only 5/59 cases (8.4%) (P<0.05). Median AMH in the two groups of patients who responded and did not respond by D4 was 708 pmol/l (97, 1926) and 107.6 pmol/l (1.5, 256) (P<0.0001). The testosterone response after prolonged HST was normal in 23/27 children with a median testosterone of 15.0 nmol/l (0.8, 43.4) and a median ΔT of 18.2 (0.57, 62.0) and abnormal in four with a median testosterone of 0.55 nmol/l (0.5, 1.0) and a median ΔT of 1.0 (0.6, 1.2). AMH was low in six children and in 3 (50%) of these cases a low D22 testosterone was observed. An AMH >5th centile was associated with a normal D22 testosterone in 20/21 cases (95%) (P<0.05). Median AMH in children who responded and did not respond at D4 and D22 was 420 pmol/l (100, 1664) and 2.8 pmol/l (1.5, 214) (P<0.05).

Conclusion: A normal AMH may provide valuable information on overall testicular function. However, a low AMH does not necessarily predict a sub-optimal testosterone response to hCG stimulation.