Systematic review and meta-analysis to examine intrapartum interventions, and maternal and neonatal outcomes following immersion in water during labour and waterbirth

Abstract

ObjectivesWater immersion during labour using a birth pool to achieve relaxation and pain relief during the first and possibly part of the second stage of labour is an increasingly popular care option in several countries. It is used particularly by healthy women who experience a straightforward pregnancy, labour spontaneously at term gestation and plan to give birth in a midwifery led care setting. More women are also choosing to give birth in water. There is debate about the safety of intrapartum water immersion, particularly waterbirth. We synthesised the evidence that compared the effect of water immersion during labour or waterbirth on intrapartum interventions and outcomes to standard care with no water immersion. A secondary objective was to synthesise data relating to clinical care practices and birth settings that women experience who immerse in water and women who do not.DesignSystematic review and meta-analysis.Data sourcesA search was conducted using CINAHL, Medline, Embase, BioMed Central and PsycINFO during March 2020 and was replicated in May 2021.Eligibility criteria for selecting studiesPrimary quantitative studies published in 2000 or later, examining maternal or neonatal interventions and outcomes using the birthing pool for labour and/or birth.Data extraction and synthesisFull-text screening was undertaken independently against inclusion/exclusion criteria in two pairs. Risk of bias assessment included review of seven domains based on the Robbins-I Risk of Bias Tool. All outcomes were summarised using an OR and 95% CI. All calculations were conducted in Comprehensive Meta-Analysis V.3, using the inverse variance method. Results of individual studies were converted to log OR and SE for synthesis. Fixed effects models were used when I2 was less than 50%, otherwise random effects models were used. The fail-safe N estimates were calculated to determine the number of studies necessary to change the estimates. Begg’s test and Egger’s regression risk assessed risk of bias across studies. Trim-and-fill analysis was used to estimate the magnitude of effect of the bias. Meta-regression was completed when at least 10 studies provided data for an outcome.ResultsWe included 36 studies in the review, (N=157 546 participants). Thirty-one studies were conducted in an obstetric unit setting (n=70 393), four studies were conducted in midwife led settings (n=61 385) and one study was a mixed setting (OU and homebirth) (n=25 768). Midwife led settings included planned home and freestanding midwifery unit (k=1), alongside midwifery units (k=1), planned homebirth (k=1), a freestanding midwifery unit and an alongside midwifery unit (k=1) and an alongside midwifery unit (k=1). For water immersion, 25 studies involved women who planned to have/had a waterbirth (n=151 742), seven involved water immersion for labour only (1901), three studies reported on water immersion during labour and waterbirth (n=3688) and one study was unclear about the timing of water immersion (n=215).Water immersion significantly reduced use of epidural (k=7, n=10 993; OR 0.17 95% CI 0.05 to 0.56), injected opioids (k=8, n=27 391; OR 0.22 95% CI 0.13 to 0.38), episiotomy (k=15, n=36 558; OR 0.16; 95% CI 0.10 to 0.27), maternal pain (k=8, n=1200; OR 0.24 95% CI 0.12 to 0.51) and postpartum haemorrhage (k=15, n=63 891; OR 0.69 95% CI 0.51 to 0.95). There was an increase in maternal satisfaction (k=6, n=4144; OR 1.95 95% CI 1.28 to 2.96) and odds of an intact perineum (k=17, n=59 070; OR 1.48; 95% CI 1.21 to 1.79) with water immersion. Waterbirth was associated with increased odds of cord avulsion (OR 1.94 95% CI 1.30 to 2.88), although the absolute risk remained low (4.3 per 1000 vs 1.3 per 1000). There were no differences in any other identified neonatal outcomes.ConclusionsThis review endorses previous reviews showing clear benefits resulting from intrapartum water immersion for healthy women and their newborns. While most included studies were conducted in obstetric units, to enable the identification of best practice regarding water immersion, future birthing pool research should integrate factors that are known to influence intrapartum interventions and outcomes. These include maternal parity, the care model, care practices and birth setting.PROSPERO registration numberCRD42019147001.

The use of hydrotherapy in the first stage of labour: A systematic review and meta‐analysis

“…These findings are similar to the results of the studies by Gautham and Devi (2020) and Zhang and Yang (2022). Contrary to our study, two studies found that water immersion was effective in reducing postpartum haemorrhage (Burns et al, 2022; Cristina et al, 2022). That these results did not indicate that hydrotherapy had a negative effect on postpartum haemorrhage, considered a major cause of maternal death, implies that the practice can be used as a safe option in intrapartum care.…”

“…This study showed that the use of hydrotherapy in the first stage of labour effectively reduces the intensity of pain. Similar results were reported in previous studies (Burns et al, 2022; Cluett et al, 2018; Cowan et al, 2017). It has been asserted in the literature that by reducing the level of vasopression, hydrotherapy increases uterine perfusion, thereby facilitating neurohormonal interactions and resulting in less pain (Henrique et al, 2018; Mascarenhas et al, 2019).…”

“…This study found that hydrotherapy does not affect the development of first-, third-or fourth-degree lacerations or episiotomy rates. Unlike these findings, previous systematic reviews reported that the rate of episiomy was lower in the hydrotherapy group (Burns et al, 2022;Zhang & Yang, 2022). Cristina et al (2022) reported that there was no significant difference in the rate of third-and…”

“…This study demonstrated that hydrotherapy applied in the first stage of labour increases comfort but that the use of analgesics does not change. Other studies indicated that hot showering during labour increased satisfaction and postpartum comfort levels (Burns et al, 2022; Shaw‐Battista, 2017; Stark, 2013). Our meta‐analysis results are similar to reports in the literature, but only one study could be detected that addressed the use of analgesics (Sidebottom et al, 2020).…”

“…One recent systematic review and meta‐analysis focused only on neonatal outcomes of hydrotherapy (Vanderlaan et al, 2018), and another included very few studies on hydrotherapy (Domínguez‐Solís et al, 2021). Three other reviews focused on specific outcomes related to maternal and infant health (Burns et al, 2022; Cristina et al, 2022; Zhang & Yang, 2022). Unlike these systematic reviews, this study reports more comprehensive results specifically on the effects of hydrotherapy use in the first stage of labour on maternal and infant health.…”