The effect of epididymal sperm cryopreservation on neonatal birthweight following PESA-ICSI

Purpose To compare the neonatal birthweight of singletons derived from ICSI cycles with fresh or frozen–thawed epididymal sperm in patients with obstructive azoospermia. Methods A total of 436 singletons derived from ICSI cycles with fresh ( n = 220) or frozen–thawed ( n = 216) epididymal sperm in obstructive azoospermia evaluated from 2012 to 2018 in the retrospective study. Multivariate generalized linear model was used to analyze the association between epididymal sperm cryopreservation and neonatal birthweight. Results The crude birthweight and z -score in neonates derived from frozen–thawed epididymal sperm were significantly lower than those from fresh epididymal sperm (3186.57 g vs 3303.61 g and − 0.18 vs 0.08, respectively), with a mean difference of 117.04 (95% CI 32.36–201.72) g and 0.25 (95% CI 0.06–0.45). Adjusted for confounders including parental age and BMI, maternal ovarian reserve, paternal FSH and T levels, peak E2 during OPU cycles, frozen–thawed embryo transfer, embryo development stage, gestational age, maternal parity and child gender, the multivariate model suggested that singletons conceived from ICSI with fresh epididymal sperm was on average 91.21 g heavier than those conceived from ICSI with frozen–thawed epdidiymal sperm (95% CI 12.72 to 166.7, P = 0.016). Conclusion Cryopreservation of epididymal sperm may negatively affect birthweight.