Water immersion during labor and birth significantly reduced use of medications, maternal pain, and postpartum hemorrhage, compared with standard care with no water immersion, based on data from 36 studies including more than 150,000 women.
“Resting and laboring in water can reduce fear, anxiety, and pain perception; it helps optimize the physiology of childbirth through the release of endogenous endorphins and oxytocin,” and data from randomized, controlled trials have shown a reduced need for epidural analgesia with water immersion, Ethel Burns, PhD, of Oxford (England) Brookes University Faculty of Health and Life Sciences, and colleagues wrote.
Although previous studies have not shown an increased risk for adverse events for newborns following water birth, “There is a need to understand which clinical practices, when performed as part of water immersion care, result in the optimum outcomes for mother and newborn,” the researchers said.
In a systematic review and meta-analysis published in BMJ Open, the researchers identified studies published since 2000 that examined maternal or neonatal interventions and/or outcomes when birthing pools were used for labor and/or birth.
The primary objective was to compare intrapartum interventions and outcomes for water immersion during labor with standard care with no water immersion.
Water immersion generally involves the use of a birth pool for relaxation and pain relief in early labor, and some women proceed with immersion through the second stage of labor and delivery. Of the 36 included studies, 31 took place in a hospital setting, 4 in a midwife-led setting, and 1 in a mixed setting. Most of the studies (25) involved women who planned to have/had a water birth, and these studies included 151,742 women. Another seven studies including 1,901 women involved in water immersion for labor only, three studies including 3,688 women involved in water immersion during labor and water birth; the timing of water immersion was unclear in the remaining study of 215 women.
Overall, water immersion significantly reduced the use of epidurals (odds ratio, 0.17), injected opioids (OR, 0.22), and episiotomy (OR, 0.16). Maternal pain and postpartum hemorrhage also were significantly reduced with water immersion (OR, 0.24 and OR, 0.69, respectively).
Maternal satisfaction was significantly increased with water immersion, and the odds of an intact perineum increased as well (OR, 1.95 and OR, 1.48).
The overall odds of cord avulsion increased with water immersion (OR, 1.94), but the absolute risk was low, compared with births without water immersion (4.3 vs. 1.3 per 1,000). No significant differences in other identified neonatal outcomes were observed across the studies.
The study findings were limited by several factors including the inconsistency of reporting on birth setting, care practices, interventions, and outcomes, and the inclusion of only three outcomes for meta-regression analysis, the researchers noted. In addition, only four studies were conducted in midwifery-led settings.
“This is important because birth pool use is most prevalent in midwifery-led settings,” the researchers wrote.” Evidence-based practice of water immersion requires research that reflects the context of care provision.
“We suggest that studies incorporate the following fundamentals to advance the evidence: birth pool description, clearly described maternal and obstetric characteristics, the birth setting, the care model and use of standardized definitions.”
Despite the limitations and need for additional research, the data overall support the potential benefits from water immersion births for healthy women and newborns, the researchers concluded.
A Clinical Report issued by the American Academy of Pediatrics in January 2022 advised against water immersion during the second stage of labor and delivery. According to the report, the potential for neonatal infections from organisms such as Legionella and Pseudomonas species, is low, but does exist, and could result in serious complications.