The influence of the moon on births - Myth or reality?

L'influence de la lune sur les naissances - Mythe ou réalité ?

The moon is said to influence our bodies, our behavior and even births ... But should we believe it? Are there really more births on new moon days?

Are there more births during full moons?

Some obstetricians and midwives say they have more births on the nights of the full moon, sometimes to the point of being overwhelmed compared to the rest of the time. As you know, the moon cycleinfluences the tides. The human body is 65% water, and the baby is bathed in amniotic fluid. So there's a belief that the moon may have an influence on amniotic fluid, and therefore on the number of births.

There are also similarities between the lunar cycle, which lasts 29.5 days, and the menstrual cycle, which lasts 28 days. The length of a woman's cycle varies from woman to woman, more or less matching that of the moon... For some, this is enough to suggest that there are more births during a full moon. But what do the scientists say?

Birth and the full moon: what do scientists think?

A number of studies have been carried out on the subject. In 1998, American scientists at Long Island Hospital (New York) observed birth statistics dating back to 1994 (equivalent to 12 lunar cycles and 3706 births). They were able to compare all births that took place at the time of the full moon, during the new moon, during the first quarter and finally during the last quarter. But the differences between the number of births in relation to the four stages of the cycle were not large enough to be conclusive.

In 2005, a new American study took into account the eight phases of the moon, compared with the 564,039 births that took place between 1997 and 2001. Again, these studies showed no conclusive results.

However, a Spanish study from 2004 suggested that the full moon had an impact on the number of births. But this study was flawed in itsdata collection andanalysis. Scientists agree that there is no direct link between the onset of labor and the full moon.

Moon phases and the number of births: a popular belief?

Even though tangible, factual scientific evidence has been available for many years, many people still believe that there is a link between the phases of the moon and the number of births. But where does this belief come from? And why does it continue to be passed down from generation to generation?

It's down to "confirmation bias", i.e. the fact that most people interpret the information they're given in a way that contradicts scientific data and confirms their beliefs.

A simple example: if they hear good news on a full moon day, they'll remember it and associate happiness with the astral phenomenon, because it confirms their belief. At the same time, days without a full moon are forgotten, since they don't confirm the received idea.

This type of thought process can be found in many other beliefs. It's a psychosomatic phenomenon due to the beliefs that are part of our cultural capital.

The FAQ of the moon's influence on childbirth

Childbirth and the impact of the full moon: is there a link between lunar attraction and childbirth?

The impact of the moon on the menstrual cycle is a popular belief. However, statistics and studies carried out by scientists who have studied the subject come to the same conclusion: there is no link between different moons and childbirth.

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The information contained in the articles on is general information only. Although reviewed by health professionals, this information is not error-free, does not constitute health advice or consultation, and is not intended to provide a diagnosis or suggest a course of treatment. Under no circumstances may this information be used as a substitute for medical advice or consultation with a healthcare professional. If you have any questions, please consult your doctor.