To the Editor:
Women experience a notable decrease in oocyte production in their late thirties; however, the effect of age on spermatogenesis is less well described. Indeed, while there are no known limits to the age at which men can father children, the effects of advanced paternal age are incompletely understood. Reproductive concerns related to advanced paternal age are less well defined (1) with a recent whole-genome sequencing study suggesting an increased risk for rare de novo mutations for older fathers (2). Whether the risk for major birth defects from de novo mutations is greater than the risk from assisted reproduction remains unknown (3).
Our retrospective study showed that sperm retrieval rates in men undergoing microdissection testicular sperm extraction (TESE) was not negatively affected by age (4). Despite the limited number of men in this study as pointed out by Kim (5), it remains the largest study to evaluate the effect of male age on sperm retrieval in nonobstructive azoospermia (NOA). The sperm retrieval rates were similar in men <30 years of age, 30 to 50 years of age, and older than 50 years of age (~50 – 60%). We identified that most men over 50 years of age who had successful sperm retrieval had hypospermatogenesis histology on previous diagnostic biopsy. It is possible that some older men with NOA may have secondary azoospermia with sperm detectable in the ejaculate at an earlier age. Therefore, it is likely that older men may be more likely to have acquired NOA (i.e., secondary infertility), whereas younger men may be more likely to have congenital NOA. Read the rest of this entry »