Study: Quality of sperm worsens with age

LIVERMORE, Calif., June 6 (UPI) -- A U.S. study says the genetic quality of sperm worsens as men get older, increasing the risk of infertility, unsuccessful pregnancies and congenital defects.

Lawrence Livermore National Laboratory and the University of California, Berkeley, found a steady increase in sperm DNA fragmentation with increasing age of the study participants -- along with increases in a gene mutation that causes achondroplasia, or dwarfism.

The researchers analyzed DNA damage, chromosomal abnormalities and gene mutations in semen samples from the same subjects -- 97 healthy, non-smoking Lawrence Livermore National Laboratory employees and retirees between 22 and 80 years old.

"This study shows that men who wait until they're older to have children are not only risking difficulties conceiving, they could also be increasing the risk of having children with genetic problems," said co-lead author Andrew Wyrobek of Lawrence Livermore National Laboratory.

The findings appear in the online edition of the Proceedings of the National Academy of Sciences.