Know Your Fertility

Get pregnant naturally. Avoid pregnancy naturally.

Artificial Light and Fertility

Artificial light may be affecting your menstrual cycle, and your fertility.

Our sleepless society surrounds us with an  abundance of man-made light – even during times we call dark. This artificial light while we sleep appears to interfere with the production of melatonin, a hormone associated with ovarian activity.
Research studies by Joy DeFelice, R.N., B.S.N. P.H.N. at Sacred Heart Medical Center in Spokane, Washington, showed that women’s cycles usually normalize when artificial light is eliminated while sleeping. Eliminating the artificial light seems to allow the hormonal system to reset itself, so to speak, and take a fresh start. Couples who were thought to be infertile have been able to conceive by eliminating artificial light while sleeping.
In these studies, couples slept in total darkness. Eliminating the sources of light usually resolved many, if not all, of the fertility difficulties. If the cycle had not normalized after three cycles in darkness, a small amount of light, such as a night light or outside moonlight, was introduced during sleep when signs of ovulation began.

Other experiments with light on laboratory rats had found that melatonin formation is on a clear 24-hour rhythm that is entirely dependent on the light-dark cycle. In continuous light, the rat’s pineal gland shrinks, puts out less melatonin, and ovarian activity increases. In continuous darkness, the opposite occurs.

These findings lead Joy DeFelice, the author of the studies on artificial light and fertility, to postulate that when the 24 hour rhythmic level of melatonin is lost due to the presence of abnormal levels of light at night, both the normal progression of hormonal events within the menstrual cycle and the normal circulating levels of each reproductive hormone can become disrupted.

Those women sleeping in darkness attained a more normal menstrual cycle and subsequently a high success rate in achieving pregnancy if no contributory medical factors were present.

My own daughter participated in this study. Her cycles were irregular and long – sometimes with no ovulation or menstruation at all for over eight months.  In order to participate in the study, she bought darkening cloth and velcroed it to the window frames. She removed the clock radio with it’s glowing clock, and rolled a beach towel into a tube to block light that might enter under the door.

Her cycles normalized within a few months, and she was able to conceive her first child. –


Marie Zenack,