Does water therapy provide measurable benefits to childbirth?

Question

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.

Other sources repeat the claim about stress on the perineum:

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?

Answer 1

The Cochrane Collaboration very recently a systematic review on the subject, where they look at all of the published evidence, weigh it up and explain what it says. (I don't believe in appeals to authority, but the Cochrane Collaboration make me think twice about my position...)

• Cluett ER, Burns E. Immersion in water in labour and birth. Cochrane Database of Systematic Reviews 2009, Issue 2. Art. No.: CD000111. DOI: 10.1002/14651858.CD000111.pub3

The review looked at 12 different studies, involving over 3000 women. While that was insufficient for robust conclusions in all areas, they found that water immersion in the first stage of labour:

Positive effects :

• a significant reduction in the epidural/spinal/paracervical analgesia/anaesthesia rate
• a reduction in duration of the first stage of labour by about 30 minutes

No Difference

• assisted vaginal deliveries
• caesarean sections
• use of oxytocin infusion
• perineal trauma
• maternal infection
• Apgar score less than seven at five minutes
• neonatal unit admissions
• neonatal infection rates

They reached more limited conclusions (e.g. higher levels of satisfaction) about water immersion in the second stage of labour, and found no studies about the third stage.

The authors conclude:

Evidence suggests that water immersion during the first stage of labour reduces the use of epidural/spinal analgesia and duration of the first stage of labour. There is limited information for other outcomes related to water use during the first and second stages of labour, due to intervention and outcome variability. There is no evidence of increased adverse effects to the fetus/neonate or woman from labouring in water or waterbirth. However, the studies are very variable and considerable heterogeneity was detected for some outcomes. Further research is needed.

I went into this with a particular expectation, and was happy to see it overturned by the evidence.

Answer 2

There does seem to be quite a bit of information regarding water birth online. My mother happens to be a midwife practicing home/birth-center birth and uses tubs in both locations. A cursory search across Google found the following: Immersion in Water During Labour and Birth (Royal College of Obstetricians and Gynaecologists/Royal College of Midwives Joint Statement No. 1) (U.K.) Specifically #5 under 'Labouring in water':

5.) Most of the available evidence, both randomised and observational, is restricted to healthy women with uncomplicated pregnancy at term, although induction of labour and previous caesarean section have been managed using water for labour and birth without reported problems. A randomised trial by Cluett et al. on women with prolonged labour found reduction in obstetric intervention following immersion in water but a higher number of babies who needed admission to the neonatal unit. Although there is clearly a need for more research, the currently available evidence does not justify discouraging women from choosing immersion in water during labour.

Additionally, according to a U.S. National Library of Medicine, National Institutes of Health publication: Maternal and perinatal outcomes amongst low risk women giving birth in water compared to six birth positions on land. A descriptive cross sectional study in a birth centre over 12 years.

The aim of this study was to determine rates of perineal trauma, postpartum haemorrhage and five-minute Apgar scores amongst low risk women in a birth centre who gave birth in water compared to six birth positions on land.

[...]

FINDINGS: waterbirth (13%) and six main birth positions on land were identified: kneeling/all fours (48%), semi-recumbent (12%), lateral (5%), standing (8%), birth stool (10%) and squatting (3%). Compared to waterbirth, birth on a birth stool led to a higher rate of major perineal trauma (second, third, fourth degree tear and episiotomy) (OR 1.40 [1.12-1.75]) and postpartum haemorrhage (OR 2.04 [1.44-2.90]). Compared to waterbirth, babies born in a semi-recumbent position had a significantly greater incidence of five-minute Apgar scores <7 (OR 4.61 [1.29-16.52]).

CONCLUSIONS: waterbirth does not lead to more infants born with Apgar score <7 at 5mins when compared to other birth positions. Waterbirth provides advantages over the birth stool for maternal outcomes of major perineal trauma and postpartum haemorrhage.

To answer your questions: 1. Are there measurable benefits backed by scientific research for water therapy (anything ranging from showers or sponge baths to full immersion)? - I would say that there is. According to the first source there is evidence that labouring in water can provide some of the benefits you mention. 2. Are any of the above claims, particularly a reduction in perineum tearing or episiotomy rates, backed by research? - It would appear that the issue is becoming more studied and that there are some positive indications that Water Birth can provide lower risk of perineal trauma.