We all know getting enough sleep is an essential part of a healthy lifestyle. But is your late bedtime potentially harming your fertility?

Researchers at Harbin Medical University, China, have recently found that a bedtime after midnight can adversely affect healthy sperm.

Results from the study indicate that Men who sleep less than 6 hours per night have lower sperm counts because their sperm died faster than men who went to sleep earlier in the evening and slept for longer hours.

A 2013 study from the American Journal of Epidemiology found similar results. In this study, men who slept for less than six hours had a 25% lower sperm count that men who slept for the recommended 8 hours.

Researcher believe that the combination of a late bedtime and shorter resting hours triggers an increase in an anti-sperm antibody. This protein antibody produced by the immune system blocks the sperm’s movement, preventing the healthy sperm from fertilizing the egg.

Unfortunately, sleeping in and for longer than 8 hours won’t help your sperm count either. The Harbin study also found that participants who slept over 9 hours also had the same anti-sperm antibody reducing their healthy sperm count.

A related study from 2016 found most testosterone is released during sleep, which may be why not getting enough sleep can affect fertility.

So set a bedtime alarm and make sure you are getting your 7-8 hours of recommended sleep per night. Just DVR your favorite late-night show, it can wait until morning.