Epididymal Versus Testicular Sperm for ICSI in Obstructive Azoospermia: Embryological, Clinical, and Neonatal Outcomes in a Retrospective Cohort

BACKGROUND: Whether sperm source influences intracytoplasmic sperm injection (ICSI) outcomes in men with obstructive azoospermia (OA) remains uncertain. OBJECTIVE: To compare embryological, clinical, and neonatal outcomes of ICSI using percutaneous epididymal sperm aspiration (PESA)- versus testicular sperm aspiration (TESA)-derived sperm in men with OA. MATERIALS AND METHODS: This single-center retrospective cohort study enrolled a total of 1368 ICSI cycles from couples diagnosed with OA at a tertiary reproductive medical center between January 2015 and August 2022. Embryological outcomes were analyzed in 1368 ICSI cycles (PESA, n = 516; TESA, n = 852). Clinical outcomes were evaluated in 869 fresh day-3 cleavage-stage embryo transfer cycles (PESA, n = 399; TESA, n = 470). Neonatal outcomes were assessed among 262 singleton live births following fresh day-3 embryo transfer (PESA, n = 128; TESA, n = 134). Multivariable regression models were used to adjust for prespecified covariates. RESULTS: In adjusted analyses, TESA (vs. PESA) was associated with a lower 2-pronuclear (2PN) fertilization rate (β = -0.03, p = 0.010) and a lower usable embryo rate (β = -0.12, p < 0.01). In the fresh day-3 transfer cohort, sperm source was not significantly associated with clinical pregnancy, miscarriage, or live birth per transfer (all p > 0.05). Among singleton live births, TESA was associated with lower birth weight (β = -209.01 g, p < 0.01) and lower odds of large for gestational age (OR = 0.45, p = 0.03), whereas gestational age, preterm birth, and small for gestational age were similar between groups. DISCUSSION: PESA was associated with better early embryological outcomes, but these differences did not translate into improved clinical pregnancy or live birth rates. Differences in neonatal growth were also observed, which remain to be further verified in subsequent studies. CONCLUSION: In men with OA undergoing ICSI and PESA- and TESA-derived sperm showed distinct embryological and neonatal growth characteristics, which merits clinical attention. The choice between PESA and TESA should therefore be individualized according to the clinical context and patient-specific considerations.