Sure, they said that 51% of women sleep curled up on their sides. But why?

Because we are "shy and sensitive souls"? I don't think so!

Sleeping on the left side during pregnancy allows a supine-sleeping woman to suffer fewer sleep disruptions from cramps and "sleeping" legs and feet (as in "pins and needles") caused by the additional weight of the baby pressing down on her femoral artery and her spine. Curling the legs up a little prevents her from rolling over onto her back as often. Also, digestion becomes more difficult later in the pregnancy, and so sleeping on her side will allow for less heartburn.

Sleeping prone is impossible for obvious reasons, unless the mattress is a very peculiar shape indeed.

A couple of pregnancies is enough to form a habit. More than a couple is more than enough. Left-handed people can be trained to use their right against their inclinations by the use of physical force. A natural inclination to sleep in a certain way can be overcome by avoiding the negative results that it causes.

Hope that acid reflux doesn't keep you awake!

Regards--
Mary Anne