Fresh semen quality in ejaculates produced by nocturnal emission in men with idiopathic anejaculation

Sperm motility and normal morphology were higher in idiopathic anejaculation patients who collected their sperm by nocturnal emissions than in those who collected their sperm by penile vibratory stimulation or electroejaculation.


Xianghu Meng, Ph.D., Longchang Fan, M.D., Jihong Liu, Ph.D., M.D., Tao Wang, Ph.D., Jun Yang, Ph.D., JunKai Wang, M.S., Shaogang Wang, Ph.D., Zhangqun Ye, Ph.D., M.D.

Volume 100, Issue 5, Pages 1248-1252, November 2013



To compare the quality of fresh semen samples collected by nocturnal emission (NE), penile vibratory stimulation (PVS), or electroejaculation (EEJ) from idiopathic anejaculation patients with those collected by masturbation from healthy control subjects.


Retrospective clinical study.


University medical center.


Ninety-one men with idiopathic anejaculation.


NE, PVS, EEJ, computer-assisted semen analysis system.

Main Outcome Measure(s):

Sperm volume, concentration, motility, and morphology.


The mean percentage of motile sperm in the NE group was 30.6% ± 3.5% (range 11.2%–50.9%), which is 1.5- and 1.9-fold higher than that of the PVS (20.5% ± 1.3%, range 6.9%–40.2%) and EEJ (16.1% ± 0.9%, range 3.7%–27.3%) groups, respectively. The percentage of sperm that have normal morphology in the NE group was 61.4% ± 4.8%, which is significantly higher than that in the PVS (38.4% ± 2.8%) and EEJ groups (29.5% ± 1.7%), respectively. However, compared with the healthy control group, the sperm motility and normal morphology in the NE, PVS, and EEJ groups were significantly lower. The sperm concentration in the NE group (149.4 ± 16.3 ×106 mL−1) was similar to that of the PVS group (143.8 ± 13.1 × 106 mL−1) but was higher than in the EEJ group (96.3 ± 8.6 × 106 mL−1) and lower than in the control group (225.0 ± 15.0 × 106 mL−1). Furthermore, the semen volume in the NE group (2.6 ± 0.2 mL) was lower than that of the control group (3.0 ± 0.1 mL).


This study is the first to report on the quality of fresh semen obtained by NE in patients with idiopathic anejaculation. Sperm motility and normal morphology were higher in patients who collected sperm by NE than in those who collected sperm by PVS and EEJ.

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