Guess What? The Full Moon Did Not Help Kate Middleton Have Her Baby

Illustration for article titled Guess What? The Full Moon Did Not Help Kate Middleton Have Her Baby

The Duchess of Cambridge had her long overdue baby this morning, two days in advance of the full moon. The only reason I bring up the moon is that yesterday, the media was reporting that a full moon Monday might just trigger a royal birth. Only thing is, that’s a crock of crap.


Top image: Chris Isherwood / Flickr

For thousands of years, humans have suspected the moon of influencing our affairs. We’ve tied lunar cycles to everything from childbirth to injuries to murderous rage—indeed, the word “lunatic” was first used to describe a person who suffers period bouts of insanity that align with the full moon.

There’s no nice way of saying it, so I’ll be blunt. These beliefs are wrong, out of line with the overwhelming majority of scientific evidence. And yet, as I wrote for Motherboard last month, superstitions about the moon run deep in society even today, and are particularly prevalent among certain groups of healthcare professionals.

As is often the case in these situations, a small number of scientific papers have been held up in support of a flawed belief. Take this 2004 study, which concluded that the number of hospital admissions for gastrointestinal bleeding was significantly higher during the full moon. But as UCLA astronomer Jean-Luc Margot outlined recently in a rebuttal paper, this study bears methodological and statistical errors that completely invalidate its results, including incorrectly matching the full moon to a substantial number of days in the dataset.

What does the scientific literature have to say about lunar cycles and childbirth? A four year study that tracked over 12,000 live births at a UCLA hospital from 1974-1978
found no correlation with the lunar cycle whatsoever. A decade later, a review of 21 studies from ten different countries found no relationship between lunar cycles and birth rates, and that individual studies which did see a correlation were inconsistent with each other. A review of six additional studies from five different countries in the mid 90’s likewise found no relationship. A review of 168 thousand births in Phoenix between 1995 and 2000 showed no correlation with lunar phase. I could go on, but I think you get the picture.

Here’s the thing. The lunar cycle doesn’t influence birth rates, and while this might seem like a rather harmless superstition, harboring beliefs that are out of line with science and reason in relatively benign areas can lead to more dangerous types of false thinking. So let’s all stop blaming the moon for interfering with our affairs, or at least, be prepared to back up the assertion with scientific evidence.


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Aaron Davis

Just because the moon has no effect on humans now (post-industrialization) that doesn’t mean that the moon didn’t have a huge effect before artificial light.

Humans brain chemistry is very sensitive to light, we know this from the effect of light color and intensity on sleep patterns.

When you have a regular pattern of natural light, with no other light sources to interfere with it, the human brain synchronizes to that light. If the 24-hour cycle of the Sun has an effect on short term biological cycles, why wouldn’t the 28-day cycle of the moon have an effect on long-term cycles (assuming the moon is the dominant light source at night)

Unfortunately, the few places in the world that are still primitive enough for the moon to affect birth cycles are also too primitive enough to have birth records (one possible exception would be North Korea, so it would be interesting to see a study based on their records some day)

This highlights a problem with studies in general. If you have the level of technology needed to study something, whatever you are trying to study will have been tainted by that level of technology.