OBJECTIVETo investigate the differences in semen quality between samples collected by masturbation in the clinic and at home.

METHODSBased on the WHO guidelines, we analyzed the ejaculates collected by masturbation in the clinic and at home from 342 men under infertility assessment and measured the contents of such biochemical markers in the seminal plasma as neutral α-glucosidase, zinc, and fructose. According to the location of semen collection, we divided the samples into two groups, clinic-collected and home-collected, and analyzed the differences in the semen parameters between the two groups with the SPSS 16.0 software.

RESULTSCompared with the clinic-collected semen, the home-collected samples had significantly higher mean values in semen volume (4.0 vs 4.9%), sperm concentration (41 vs 64 x 10(6)/ml), total sperm count (175 vs 270 x 10(6) per ejaculate), progressive sperm motility (40 vs 52%), total count of progressively motile sperm (82 vs 135 x 10(6) per ejaculate) (all P <0.05). No significant differences were found between the two groups in normal sperm morphology (4.0 vs 5.0%) and the contents of neutral α-glucosidase (26 vs 24 mU per ejaculate), zinc (8.0 vs 8.0 μmol per ejaculate), and fructose (62 vs 60 μmol per ejaculate) (all P >0.05). Abnormal sperm concentration (<20 x 10(6)/ml) was observed in significantly fewer of the home-collected samples than the clinic-collected ones (18% [62/342] vs 30% [103/342], P<0.05), and so was abnormal progressive sperm motility (<32%) (64% [219/342] vs 75% [256/342], P<0.05).

CONCLUSIONOur findings show that semen samples collected by masturbation at home has a higher quality than those collected in the clinic. So the location of semen collection should be taken into consideration in infertility investigation.