Negative influence of paternal age on clinical intracytoplasmic sperm injection cycle outcomes in oligozoospermic patients.

OBJECTIVE: To evaluate the effect of male age on clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles, according to sperm concentration.
DESIGN: Retrospective, observational study.
SETTING: Assisted reproduction center. PATIENT(S): The study included 1,024 couples undergoing ICSI cycles with fresh spermatozoa. INTERVENTION(S): The influence of paternal age on ICSI outcomes of oligozoospermic and normozoospermic patients was evaluated. MAIN OUTCOME MEASURE(S): Rates of high-quality embryos, pregnancy, implantation, and miscarriage were evaluated through linear logistic regression analyses. RESULT(S): When the sperm concentration was abnormal, paternal age influenced implantation (regression coefficient value = -0.7009) and pregnancy rates (odds ratio = 0.95, 95% confidence interval 0.91-0.99). However, in normozoospermic patients, no influence of paternal age was observed on implantation (regression coefficient value = 0.0566) or pregnancy rates (odds ratio = 1.00, 95% confidence interval 0.97-1.03). CONCLUSION(S): For couples in which the men are oligozoospermic, the implantation rate could be impaired by increased paternal age. In these couples, the chance of pregnancy decreased 5% for each year of paternal age. When men are normozoospermic, this effect is not observed. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.