COPENHAGEN, Denmark, Dec. 4 (UPI) -- European researchers say reduced male fertility -- affecting one in five men with problems including subfertile semen -- may be contributing to low birth rates.
The report suggests reduced male fertility may be making it even harder for couples to conceive and increasing demand for assisted reproduction techniques such as in vitro fertilization.
"The important impact of men's reproductive health on a couple's fertility is often overlooked," report co-author Niels Skakkebaek of the University of Copenhagen says in a statement. "While poor sperm may be part of the reason more couples are using in vitro fertilization, it may also be making those therapies less successful."
Skakkebaek and colleagues say the increase in male fertility problems -- dropped sperm counts to the degree that one in five men in Europe ages 18-25 have semen quality in the subfertile range, declining testosterone levels, as well as more developmental abnormalities such as undescended testes -- calls for a common strategy to target research.
The decline in male reproductive health has occurred in just a few decades, suggesting to the researchers environmental and lifestyle factors are involved rather than genetics.
The report, published by the European Science Foundation, was also presented in Paris.
