Effects of Water Immersion Versus Epidural as Analgesic Methods during Labor among Low-Risk Women: A 10-Year Retrospective Cohort Study

Abstract

Background: Adequate pain relief during childbirth is a very important issue for women and healthcare providers. This study investigates the effects on maternal and neonatal outcomes of two analgesic methods during labor: water immersion and epidural analgesia.

Methods: In this retrospective observational cohort study at a first-level hospital, in Spain, from 2009 to 2019, 1134 women, low-risk singleton and at term pregnancy, were selected. Among them, 567 women used water immersion; 567 women used epidural analgesia for pain control. Maternal outcomes included mode of birth and perineum condition. Neonatal outcomes included 5 min Apgar score, umbilical cord arterial pH, and Neonatal Intensive Care Unit admissions. Chi-square tests and Mann-Whitney U tests, together with their effect sizes (Cramer's V, odds ratio, and Cohen's d) were used to test the main hypotheses.

Results: Spontaneous vaginal birth was almost 17 times more likely in the water immersion group (OR = 16.866 [6.540, 43.480], p < 0.001), whereas the odds of having a cesarean birth were almost 40 times higher in the epidural group (OR = 39.346 [3.610, 429.120], p < 0.001). The odds of having an intact perineum were more than two times higher for the water immersion group (OR = 2.606 [1.290, 5.250], p = 0.007), whereas having an episiotomy was more than eight times more likely for the epidural group (OR = 8.307 [2.800, 24.610], p < 0.001). Newborns in the water immersion group showed a better 5 min Apgar score and umbilical cord arterial pH and lower rates in admissions at the Neonatal Intensive Care Unit.

Conclusions: Women choosing water immersion as an analgesic method were no more likely to experience adverse outcomes and presented better results than women choosing epidural analgesia.

Keywords: analgesia; epidural; maternal and newborn outcomes; pain relief; perineal trauma; water immersion; waterbirth.

Figure 1

Women attended to during the study period at the maternity ward and establishment of the groups.

Figure 2

Standardized residuals for maternal outcomes among study groups. Notes: SVB = spontaneous vaginal Birth; OVB = operative vaginal birth; CS = cesarean section; Minor l. = minor laceration; Major l. = major laceration.

Figure 3

Standardized residuals for newborn outcomes among study groups. Notes: HNs = healthy newborns; NDTPs = newborns with difficulties in the transitional period; NICUs = newborns admitted to Neonatal Intensive Care Units; Not NICUs = newborns who did not require Neonatal Intensive Care Units.