Sleeping on your left side during pregnancy
Q
Why is it better to sleep on your left side when pregnant?
A
The answer to this question lies in the anatomy of the abdomen, which has
to harbor the ever-increasing uterus as the baby grows.
The Vena Cava is
the main vein that drains the entire lower half of the body. Anatomically,
it lies just to the right of the midline--just on the right side of your
spine. As the baby gets bigger, certainly the heavier uterus, lying flat
on the Vena Cava will (like stepping on a garden hose) obstruct flow up
towards the heart. The drainage of the lower half of the body becomes sluggish,
which not only increases the swelling of your ankles, feet, and legs, but
will also impact on hemorrhoids as well. And decreased return of blood
flow to the heart will cause hypotension (lowered blood pressure) down
the line and resulting diminished arterial blood flow to the uterus, placenta,
and baby.
Sometimes this hypotension is evident when a woman
has an ultrasound, during which she lies flat. One of the symptoms of hypotension
is nausea that will accompany the light-headedness. In answer to your question,
lying on the back is the worst ossible position in the third trimester.
Lying on the right side is better than lying on your back, but lying
on your left side is the best of all, because this is the position which
will have the least amount of weight upon the Vena Cava.
