Available now in pre-release online, ACOG's update on their April 2014 Opinion on Hydrotherapy contains some interesting and impactful aspects. Here is a synopsis of the November 2016 Opinion Update.
ACOG states that hydrotherapy/water immersion is advisable for uncomplicated pregnancies, and labors that occur after 37 0/7 and 41 6/7 weeks. They suggest that labors may be shorter when hydrotherapy is in use, and the incidence of epidural anesthesia is reduced. This implies, as both evidence-based information and anecdotal information shows, that hydrotherapy reduces the perception of pain during labor.
While the opinion says that sufficient evidence does not exist to fully inform laboring women of the risks and benefits of hydrotherapy, the opinion states that the laboring woman should not only be advised of risks and benefits but also the hospital must establish strict protocols surrounding hydrotherapy. Until sufficient data does exist, the opinion is that birth should be on "land" rather than in "water".
Most importantly, the opinion states that "a woman may request immersion during the second stage of labor, including giving birth while submerged. This decision should represent an informed choice; a woman who requests to give birth while submerged in water should be informed that the maternal and perinatal benefits and risks of this choice have not been studied sufficiently to either support or discourage her request."
Interestingly, the references used range from the early 1990s to 2016. In fact 21 of the 39 references would be considered unusable by the "within 3-5 year" rule of references used by many hospitals, physicians, nurses, childbirth educators and other birth professionals. The opinion, however, does use the ACNM Position Statement on Hydrotherapy, the Royal College of Midwives Guidelines on Hydrotherapy and the NICE Guidelines on Intrapartum Care (includes hydrotherapy) as references.
Among the missing from the opinion is information from earlier in 2016 from the largest cohort study, with nearly 18,000 in the U.S. study. The study from the Journal ofMidwifery and Women’s Health (full text available from this link) reported separately on outcomes for mother-baby dyads. The research used in the study was from the Midwives Alliance of North America Stats Project with births during the years 2004-2009. Since the information did come from the MANA Project, the women in the project gave birth either at home or at a birth center – this may or may not make them representative of all U.S. childbearing women, as they received minimal medical intervention. The key piece to this voluminous study is that water labor/water birth did not confer an increased risk of newborn morbidity/mortality, suggesting that waterbirth “is a reasonably safe option for use in low-risk, low intervention births – especially when the risks associated with other forms of pharmacologic pain management are considered.”
To accurately discern your own opinion about water labor and water birth based on the evidence available world wide, I highly suggest the following resources:
"Birth Bath and Beyond: The Science and Safety of Water Immersion during Labor and Birth" by Barbara Harper in the Journal of Perinatal Education (2014)
Evidence Based Birth - this article is a history of waterbirth and a perspective on the previous ACOG Opinion of 2014.