Do More Births Take Place at Full Moon?

I first heard this in a podcast a couple of weeks ago, but apparently there is this idea that a full moon helps induce birth in humans.  Um...okay?  Why?  Supposedly a full moon creates a larger gravitational force, causing a fetus in the last month of term to drop, thus inducing labor and resulting in a greater chance of birth.  What the....???  What does science say?

A full moon does NOT induce labor.

To start, the gravitational force between the Earth and the moon remains the same regardless of the moon's phase.  The gravitational force depends on the mass of the Earth, the mass of the moon, and the distance between the two.  You may not see the full circular disk of the moon when it isn't full, but it's still there.  Therefore the mass of the moon does not change with phase.  This means the phase of the moon can in no way affect the gravitational force.  

The distance between the Earth and the moon does, however, change.  The moon's orbit is slightly elliptical so sometimes the moon is a bit closer than other times.  A closer distance does increase the gravitational force.  Again, however, we need to look at the numbers.  This change in gravitational force is so small, that even if it could somehow induce labor, it wouldn't.  

So there you go.  The full moon does not induce labor.  More babies are NOT born during a full moon.