When it comes to male fertility, size doesn’t matter, but length does.
Length of his sleep, that is.
Researchers found that a couple was 42 percent less likely to become pregnant in a given cycle if the man was getting less than 6 hours or more than nine of sleep — compared to men who regularly slept for 8 hours a night, according to the report presented at the annual meeting of the American Society for Reproductive Medicine.
And it’s not just the number of hours in the sack that can be detrimental to reproduction, said lead researcher Lauren Wise of Boston University. Couples were 28 percent less likely to become pregnant if the man spent more than half the night tossing and turning, Wise reported.
Although the study didn’t look at how poor sleep might impact conception, other researchers have found that shorter time in bed was linked to lower testosterone levels and poor sleep was associated with lower testosterone, fewer sperm and fewer normally shaped sperm.