Science has done a lot in recent decades to marry fact with folk wisdom regarding the moon and its so called lunar effect, but have they succeeded?
It seems like every ten years there’s a new study investigating lunar cycles and their connection to fertility rates. Most showed no correlation between lunar effects and live births. Some of the results were disappointing because they were inconclusive, like the one offered by the US Bureau of the Census Statistical Research Division from 1987. The agency looked at birth rates from different decades across the country and found problems qualifying the data because there was no way to consider only those live births where no human intervention occurred that would alter the course of nature, such as dispensing labor-inducing drugs or performing a caesarian section where the date of birth may be at the discretion of an attending physician.
Some studies rolled fertility rates in with other human experience. Kelly, Rotton and Culver conducted a “meta-analysis” of thirty-seven studies lumping human deviant behavior and random incidents (ER visits, homicides, etc.) with the occurrence of live births and the possibility of lunar effects. There was no significant correlation in their findings overall.
Many of the studies indicated that they included conception dates when computing results, but that also raises concern about the quality of the data being configured. There is very little proof that any of these studies knew from each woman’s file precisely when ovulation or conception occurred. This is why obstetricians usually chart a woman’s gestational period by the start of her last menstrual period, to avoid confusion. The study depended on the day of the delivery as the means for determining success.
Other studies, like the Menaker studies of 1957 and 1959 found 1% increase in live births at the full moon, but data was gathered in New York City, a place with virtually no natural light. One reason scientists have explored lunar effect is to find out if the moon’s light triggers childbirth. Likewise, an NIH study found a trend indicating a slight increase in births peaking at the third quarter of the moon suggesting that the period of decreasing illumination after the full moon may precipitate ovulation. But this study was, like the Menaker study, looking at New York City birth rates. Criss and Marcum from NIH underscore the point about luminosity: “The findings provide little guidance as to the timing or nature of the moon's influence (on live births), but research suggests a connection between menstrual regularity and light.”
In that vein, then, what happens when we ask a different question about the moon’s phases and the connection to women’s cycles? What if studies look specifically at moonlight’s influence on ovulation?
One eureka moment appears to have occurred at the Guru Nanak Institute in Calcutta who published their findings in 2005. In their search for the link between lunar phase and baby’s gender, they found that more boy babies were conceived during the full moon than girl babies, but more interesting for us is that the ratio from full moon conception to new moon conception was 8:1. Maybe the folks in Calcutta are more in tune with the moon than New Yorkers.
Plenty of thinkers today believe women menstruated and ovulated according to the lunar phases before artificial light become commonplace and threw off our cycles. Health and wellness guru, Dr. Christiane Northrup says, “Even in modern society, where we are cut off from the rhythms of nature, the cycle of ovulation is influenced by the moon. Studies have shown that peak rates of conception and probably ovulation appear to occur at the full moon or the day before. During the new moon, ovulation and conception rates are decreased overall.”
The moon is linked to our menstrual cycles and not just in a poetic way – Darwin believed that the menstrual cycle originated as an echo of the cycling tides when life forms advanced to dry land billions of years ago. The nurturing and protective qualities of the ocean environment were transferred to the uterus and moved by the same lunar tide that pulls the ocean.
The phrase “Lunaception” was coined by Louise Lacey and developed as both a contraceptive and fertility promoting aid. Lacey says:
“Our bodies evolved to respond to the light and dark of the moon’s rhythms, menstruating at the new moon and ovulating at the full. To reproduce that rhythm, we must shut out all light while sleeping except in mid-month, when we add a small night light to reproduce the effects of the full moon. What often happens is that your body will get in tune with the moon’s cycle and at that point you can simply throw open your drape. ”
The American Journal of Obstetrics and Gynecology gave their nod to similar ideas with Dr. Winnifred Cutler's report of the lunar cycle's influence on menstrual cycles. “The lunar cycle and a fertile menstrual cycle are the same, 29.5 days... A real phenomenon exists. Accordingly, it seems reasonable to investigate the possibility of a lunar effect upon the menstrual cycle by looking at the data in a new way.”
An ancient Assyrian/Babylonian fragment from a cuniform tablet sums it up very nicely: “A woman is fertile according to the moon.” My hunch is that this was not an argument limited only to full moons and live births. This was a declaration of the mystical relationship connecting woman’s monthly cycles to cosmic ones, the two entities paralleling one another, not in linear time, but in representation.
No matter which side of the debate one takes on the theories of lunar effect, recognize that the opportunity exists to observe the moon and its phases as an affirmation of our connection to the natural world and the cosmos. The moon and its changing face are the perfect symbolic manifestation to illustrate the changes that are occurring in a woman’s body during her reproductive years.
Shuttle, Penelope and Redgrove, Peter. The Wise Wound. New York: Grove Press, 1988.
Kelly, Ivan; Rotton, James; Culver, Roger. The Moon Was Full and Nothing Happened: A Review of Studies on the Moon and Human Behavior. New York: Prometheus Books,1986.
Northrop, Christiane. Women’s Bodies Women’s Wisdom: Creating Physical and Emotional Health and Healing. New York: Bantam, 1998.
Lacey, Louise. Lunaception: A Feminine Odyssey into Fertility and Contraception. New York: Coward, McCann & Geoghegan, 1975.
Arnold L. Lieber, M.D. The Lunar Effect. Biological Tides and Human Emotions.
Anchor Press/Doubleday, Garden City, New York, 1978