I recently watched the trailer for The Business of Being Born, which included the following quote:
"The presence of Doulas; using water during labor; these things have been scientifically shown to generate better outcomes.
I did some looking around, and found some surprising claims about water therapy as pertains to delivery.
Whattoexpect.com claims that:
One reason that water works so well is that floating eases pressure on your spine, helping the pelvis to open. Once you're in the tub (or a special birthing pool, if you're lucky) you no longer need to concentrate on your posture — your body is decompressed, which helps minimize the pain of contractions. Plus, if you give birth underwater, there's less stress on your perineum, even if tearing occurs.
Water causes the perineum to become more elastic and relaxed, reducing the incidence and severity of tearing and the need for an episiotomy and stitches.
Other specific claims include "increasing the woman's energy", making it easier to reposition the body due to the buoyancy, improved blood circulation, more effective uterine contractions, lower incidents of high blood pressure due to anxiety, and a reduction in stress-related hormones, allowing the mother’s body to produce endorphins.
Are there measurable benefits backed by scientific research for water therapy (anything ranging from showers or sponge baths to full immersion)? Are any of the above claims, particularly a reduction in perineum tearing or episiotomy rates, backed by research?