The Rhythm of Fertility

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Tick, tock… Your biological clock isn't the only clock you have to contend with when it comes to getting pregnant.

The Scoop

If you're trying to conceive, you're well-acquainted with your biological clock—but what about the body's "circadian rhythm," that natural 24-hour clock inside us that responds to light and darkness and tells our bodies to wake up or feel sleepy? Its impact on fertility may be much greater than we currently give it credit for, says researchers from Northwestern University.

In a study, researchers found that leaving a room well lit until midnight instead of turning off the lights at the usual time of 6 PM cut the fertility rate of lab mice by half after only six months. Researchers speculate that healthy fertility is linked to the body's natural light-dark/wake-sleep cycles and any changes in these circadian rhythms may get in the way of becoming pregnant, though they are still not sure why.

"If you disrupt your internal rhythms, there will be negative consequences—that is very clear," says study lead author Dr. Keith Summa. "Our results suggest people should consider their biological rhythms for optimal health."

Your Fertility

So if you're an ER nurse who pulls 18-hour shifts, does this mean you'll have trouble getting pregnant? Probably not. Some fertility experts cast doubt on this research, saying that mice are no substitute for humans when it comes to explaining the intricacies of reproduction. However, if you are experiencing fertility issues, your sleep/wake cycles might deserve a second look. According to Dr. Summa, other studies have shown that female shift workers may be more likely to experience fertility and menstrual issues, including irregular periods.

The bottom line? It's time to dim the lights! Sleep is good for your overall health and energy levels. No matter what time of day it is, if your body tells you to slow down, it's probably a good idea to listen.