Does the cause of obstructive azoospermia affect the outcome of intracytoplasmic sperm injection: a meta-analysis

OBJECTIVE: To define whether the outcome of intracytoplasmic sperm injection (ICSI) using sperm surgically retrieved from men with obstructive azoospermia (OA) depends on the cause of obstruction. PATIENTS AND METHODS: We first analysed our data and then used a meta-analysis of published data (including ours) to compare the outcome of ICSI in OA, classified in terms of congenital and acquired causes. The present study comprised 82 couples who underwent 127 ICSI cycles using surgically retrieved sperm. The cause was classified as congenital bilateral absence of vas deferens (CBAVD, in 20), after vasectomy (56), infective/inflammatory (21), noninfective (24) and ejaculatory (five). Five reports (687 cycles) including the present were identified as suitable for meta-analysis. RESULTS: Analysis of the present data showed that fertilization and live-birth rates were highest in men with a previous vasectomy and no infective cause (vasectomy 51% and 23%; not infective 53% and 29%, respectively) and lowest in men with infective or inflammatory causes. There was no difference in outcome if the sperm was fresh or frozen, or whether epididymal or testicular. Meta-analysis comparing congenital (CBAVD) and acquired causes showed a significantly increased fertilization rate (95% confidence interval, 0.84-1) with acquired causes. Meta-analysis of the three papers reporting delivery outcome showed no difference in live-birth rate but a significantly higher miscarriage rate in the congenital group (relative risk 2.67). CONCLUSION: In ICSI cycles in men with OA the cause appears to influence the outcome, but outcome is not affected by whether the retrieved sperm is fresh, frozen, epididymal or testicular. The meta-analysis suggested a higher fertilization rate and lower miscarriage rate in acquired causes of OA.