Factors Affecting FertilityDoctors and experts are constantly searching for new and improved fertility treatments that affect ovulation, egg maturity, sperm viability and more. These areas of research are crucial to the success of fertility treatments and successful pregnancy for many couples. However, infertility may be associated with more than physical imparities that can be solved with a medication or some form of assisted reproductive technology. According to a new research study, circadian rhythm may have a lot to do with menstrual and fertility cycles.

What is circadian rhythm?

If you’ve ever known someone who goes to bed at the same time every night and wakes up at dawn without an alarm clock, you already have a pretty good idea of the power of circadian rhythm. Our bodies are naturally in tune with the rise and fall of the sun. Ideally, the body rests when sunlight fades and awakens with the sunrise, but modern life is not that simple. With caffeinated beverages, long hours and multi-tasking well into the night – circadian rhythms are no longer a consideration. But, according to Fred W. Turek, they should be.

Fred W. Turek, along with several colleagues at Northwestern University, suggests a reduction in reproductive success of up to 78-percent when circadian rhythms are disrupted. The research team studied the reproductive success of lab mice. The mice were broken into three groups – control, phase (advanced) and phase (delayed). The advanced group was presented with earlier daylight cycles while the delayed group was presented with later daylight cycles. Every five days the start time for daylight changed six hours (either earlier or later depending on the group). The control group was extremely successful in reproducing with a success rate of around 90-percent. The advanced group fell at 50-percent and the delayed group just 22-percent.

While the impact of circadian rhythm on fertility and reproduction is clear in this study, researchers have no idea why there is such a great impact. As stated in the study, an impact was expected, but the severity of the impact was a surprise for all researchers.

Source: Keith C. Summa, Martha Hotz Vitaterna, Fred W. Turek. PLoS One. May 23, 2012.