Fertility Medical Group, Av. Brigadeiro Luis Antônio, 4545, Jardim Paulista, São Paulo, SP 01401-002, Brazil; Instituto Sapientiae - Centro de Estudos e Pesquisa em Reprodução Assistida, Rua Vieira Maciel, 62, São Paulo, SP 04203-040, Brazil. Electronic address: [Email]
OBJECTIVE : Are the outcomes of (i) surgical sperm retrieval (SSR) and (ii) intracytoplasmic sperm injection (ICSI) influenced by the obstructive interval (time elapsed since vasectomy)? METHODS : Medical records from 148 patients (194 cycles) with secondary azoospermia due to vasectomy, who presented for percutaneous epididymal sperm aspiration (PESA) and ICSI in a private university-affiliated IVF centre, from January 2012 to February 2017, were analysed in this historical cohort study. The obstructive interval was recorded for each couple, and its influences on the outcomes of SSR and ICSI treatment were investigated using general mixed models with adjustment for potential confounders. Clinical pregnancy rate was the main outcome measure. RESULTS : The obstructive interval was negatively correlated with the presence of spermatozoa (β = -0.032, P = 0.009) and motile spermatozoa (β = -0.031, P = 0.010) during PESA. The need to convert to testicular sperm aspiration was significantly influenced by the obstructive interval (β = 0.012, P = 0.003). The blastocyst development rate on day 5 was inversely correlated with the obstructive interval (β = -0.011, P = 0.014). Implantation and clinical pregnancy rates were negatively influenced by the obstructive interval (β = -1.107, P = 0.039 and β = -0.016, P = 0.031, respectively). The receiver operating characteristic curve analysis demonstrated that the obstructive interval has a predictive value on the achievement of clinical pregnancy (area under the curve = 0.667, P = 0.001, Youden index 0.3385, associated criterion >17 years). CONCLUSIONS : Men undertaking vasectomy should be made aware of the long-term effects and their implications for future reproductive treatment.