The Connection Between Fertility and the Moon

Moon Phase Astrology and Menstrual Cycles

Pregnant woman against a full moon.
 JTBaskinphoto / Getty Images

The moon’s sway over our sex life is part of a rhythm observed in the natural world; life force grows, becomes animated at the waxing cycle, and diminishes during the waning cycle. One observable example is crustaceans whose eggs and sperm burgeon on the building cycle, and release at the full moon.

In astrology, it is believed that the full moon creates an atmosphere of extroversion and high energy associated with love connections. This peak of sexual ardor and rising female hormones is believed to be why more babies are born on full moons than any other time. It matches the moon phase of conception exactly!

Since time began, women have watched the moon and its mirroring of their own menstrual cycle. This intimacy with life’s very rhythm made them the keepers of the blood mysteries. Many women have reclaimed this connection to Mother Moon, seeking to go with the flow, and not against it. There’s a growing interest in using lunar calendars to find the peak fertile days, which often coincide with the desire for intercourse.

Dr. Jonas' Breakthrough

In the 1950s, Dr. Eugene Jonas--a Czech doctor--brought lunar wisdom into the realm of scientific discovery. He found that women’s fertility peak during the moon phase that matches the one under which they were born.

For example, if a woman was born during the dark of the moon, her peak is the three days around that time, even if it coincides with the menstrual period. That means there are two peak periods for fertility in a month, one being the regular mid-cycle ovulation.

Quick Tips on Moon and Fertility

  • As the moon waxes, estrogen levels go up and peak at the full moon.
  • For women, the full moon is energizing and there’s less need for sleep; the radiant moonlight makes women feel alluring and receptive to sex.
  • During the waning moon, higher progesterone prepares the womb for the possibility of new life.
  • At the dark of the moon, hormones are at their lowest, and there’s a need to rest and tune in psychically, so renewal can happen. 
  • The moon’s mood lighting, the charged-up physical energies and expressive emotionality of the full moon are some reasons why it’s a peak for sexual activity.
  • Birth rates are lower in the three-day period at the new moon; this reflects the lowered libido and energy for sex at that time.
  • At the woman’s natal lunar phase, high stress or sexual intercourse can bring on “spontaneous ovulation.”
  • The lower birth rates at the new moon suggest that it’s a time of lowered libido. 
  • Your most fertile days are when the mid-cycle ovulation matches up with your own natal lunar phase.
  • The lunar phase can be calculated from your natal chart, by counting the degrees that the moon is ahead of the sun.
  • Your fertility peaks when the moon and Sun are in that same angular relationship every month.
  • There’s evidence that a man’s sperm count reaches a peak during his lunar return--when the moon is in the sign he was born in. 
  • Dr. Jonas found that the sex of a baby was in synch with whether the moon was in a masculine or feminine sign at the time of conception.
  • The masculine signs are Aries, Gemini, Leo, Libra, Sagittarius, and Aquarius.
  • The feminine signs are Taurus, Cancer, Virgo, Scorpio, Capricorn, and Pisces.
  • For your best chance at a boy baby, have sex during your fertile times when the moon is in a masculine sign. Choose a feminine sign for a girl baby.