Can preoperative parameters predict successful sperm retrieval and live birth in couples undergoing testicular sperm extraction and intracytoplasmic sperm injection for azoospermia?

Background: We aimed to determine if the success of TESE and live-birth following TESE-ICSI can be predicted from readily available preoperative parameters for couples with azoospermia. Our methodology was as follows, this was a cohort study of couples who attended the fertility service (from 2009-2019) at an NHS hospital in whom the male partner was diagnosed with azoospermia and required conventional TESE with multiple biopsies to obtain sperm. Of 414 men included, 223 had successful TESE and of those 178 have used sperm in ICSI cycle(s). Predictive models were developed using logistic regression. We assessed model performance by internally validated concordance statistics and calibration plots. Successful sperm retrieval was defined as the presence of motile sperm which survived the freeze-thaw process and live-birth defined as delivery after 34 weeks of gestation. Results: Successful TESE was associated with higher male age and lower FSH. The TESE model discriminated well with a c statistic of 0.81 (0.77-0.85). Live-birth was associated with lower maternal age, earlier ICSI cycle, and lower testicular volume. The live-birth model also discriminated well with a c statistic of 0.70 (0.64-0.76). Conclusions: These results support the pragmatic counselling of couples diagnosed with azoospermia about the chances of success of the TESE procedure and of biological parenthood prior to surgical intervention. The models help to discriminate between men who have a high or low chance of successful TESE and couples who have a higher chance of achieving a live-birth after successful TESE. This will allow couples to make a better assessment of the balance of risk versus benefit prior to commitment to surgical interventions.