Seminal plasma neutral alpha-glucosidase activity as an early predictor of patency and natural pregnancy after microsurgical vasoepididymostomy.

Microsurgical vasoepididymostomy (MVE) is recommended as a first-line option for treatment of epididymal obstructive azoospermia (EOA). However, early indicators for predicting patency and natural pregnancy are unclear. Our aim was to explore the early predictive value of seminal plasma neutral alpha-glucosidase (NAG) activity for patency and natural pregnancy after MVE. Eighty-four patients with EOA who underwent MVE were enrolled in this study. The post-operative patency and natural pregnancy rates were 60.71% and 33.33% respectively. The presence of motile epididymal spermatozoa at the anastomosis site and NAG activity measured at the first month after MVE were early and independent predictors of patency and natural pregnancy. The areas under the receiver operating characteristic curves (AUCs) of NAG activity for prediction of patency and natural pregnancy were 0.78 (95% confidence interval [CI]: 0.68-0.88) and 0.82 (95% CI: 0.73-0.92). The best cut-off values of NAG activity for predicting patency and pregnancy were 15.9 and 17.0 m IU/ejaculate respectively. In conclusion， NAG activity measured at the first month after MVE is an early and independent predictor of patency and natural pregnancy.