Frequency of subnormal hypoosmotic swelling tests increase with advancing age of the male.

Purpose: To determine if there is an increased frequency of abnormal hypoosmotic swelling (HOS) tests when testing semen in males of advanced reproductive age.

Methods: Ten-year retrospective review according to six age groups (< or = 29.9, 30-34.9, 35-39.9, 40-44.9, 45.0-49.9, and > or = 50).

Results: Compared to males < 35 years old, the frequency of HOS scores < 50% doubles in males 45-49.9 and quadruples in males > or = 50.

Conclusions: Males with low HOS scores despite having no problem with fertilization of the oocytes rarely achieve a pregnancy because of embryo implantation defects unless intracytoplasmic sperm injection (ICSI) is performed. Thus at least one abnormality seen in sperm of males of advanced reproductive age is correctable by performing in vitro fertilization with ICSI.