Girl or boy ? People have always invented various methods to try to unravel the mystery of the sex of the baby. One of them is based on the lunar calendar. Depending on the lunar cycle at the time of conception, it would indeed be possible to predict the sex of your baby …

The lunar calendar indicates the lunar cycle, which evolves with the revolution of the moon around the earth. This cycle is made up of different phases:

• the new moon: the lunar surface illuminated by the sun is not visible from the earth (black moon);
• the first crescent then the first quarter (the moon forms a semi-circle);
• the waxing gibbous moon;
• the full moon (the moon forms a full circle)
• the waning gibbous moon;
• the last quarter;
• the last crescent.

The moon is said to descend between the new moon and the full moon; rising between full moon and new moon.

This lunar cycle, also called the lunation or synodic period, lasts 29,5 days.

The lunar calendar is recognized to have an influence on the tides (via the lunar mass which exerts a force of attraction on the earth). It would also influence the growth of plants, our sleep, and even hair growth. And according to some beliefs, fertility, the sex of the baby, childbirth.

It is believed that the lunar calendar has an influence on the sex of the baby. To know if we are expecting a boy or a girl, it would suffice to know the lunar phase (ascending or descending) at the time of ovulation, and therefore of the conception of the baby.

• in the waning moon (period between the news and the full moon): it is a boy
• in rising moon (from full moon to new moon): it’s a girl.

You can also use this method to choose the sex of your baby, programming his sexual intercourse in the waning or rising moon, depending on the desired sex. According to belief of course …

At the risk of disappointing you, no scientific study has validated the reliability of the lunar calendar to predict the sex of the baby, let alone choose it! Remember that the sex of the baby is the result of chance. And everything is played at the time of fertilization, according to what we could call the “lottery of nature” …

Each cell in the body has 23 pairs of chromosomes, including one pair of XX or XY sex chromosomes. This pair is defined from the meeting between the oocyte and the spermatozoon. Everyone will bring their genetic material, 23 chromosomes and 1 sex chromosome, knowing that:

• all oocytes carry an X chromosome;
• sperm carry either an X chromosome or a Y chromosome.

If the sperm that fertilized the egg was an X sperm, the baby will carry the XX sex chromosome pair. It will be a girl. If it’s a Y sperm, the baby will carry the XY sex chromosome pair. It will be a boy. It is therefore the sperm which, from fertilization, determines the sex of the baby. To influence this choice, it would therefore be necessary to be able to select the spermatozoa, which is not possible today.