Recommended Citation
Malloy E, Luff A, Kram JJF, et al. Characteristics Associated with Tub Entry and Delivery in Water: A Secondary Analysis of Waterbirth Intervention Participants. Presented at Scientific Day; May 20, 2026; Milwaukee, WI.
Abstract
Background/Significance:
Waterbirth is a pain management option that promotes physiological birth with limited availability in US hospitals. We conducted the first US-based randomized controlled trial (RCT) of hospital waterbirth, finding it was a viable option for low-risk individuals and reduced use of intravenous narcotics and epidural analgesia while increasing satisfaction. To further support person-centered care, it is important to understand which individuals who planned waterbirth ultimately gave birth in water and how preferences and medical needs shifted during labor.
Purpose:
To identify factors linked to waterbirth tub use during labor and successful delivery in water among those planning a waterbirth.
Methods:
We conducted a secondary analysis of participants who were consented and assigned to the waterbirth arm of our RCT, 1/2022-12/2023. Waterbirth participants were offered standard intrapartum care along with the option of waterbirth. We explored tub entry and delivery in water, examining differences in age, pre-gravid BMI, gestational age, cervical dilation, induction, parity, marital status, race and ethnicity, and educational attainment. Fisher’s exact tests were used for categorical variables; Kruskal–Wallis tests for continuous variables. P values < 0.05 were statistically significant.
Results:
Of 116 waterbirth participants, 68 (58%) entered the tub. Hypertension (n=20) and desire for epidural anesthesia (n=10) were common reasons for not entering the tub. Of those who entered the tub, 41 (61%) gave birth in water. Common reasons for leaving the tub were for epidural analgesia (n=14), required cesarean or operative vaginal birth (n=6). When compared to those who did not enter the tub, tub entrants had a higher gestational age (39.7 vs 38.9 weeks, p<0.01), greater cervical dilation at admission (4.3 vs 2.0 cm, p<0.01), and were less likely to be nulliparous (38% vs 90%, p<0.01). Among tub entrants, those who gave birth in water had greater dilation at admission (4.8 vs 3.6 cm, p=0.02), were older (31.2 vs 27.5 years, p=0.01), less likely to be nulliparous (27% vs 56%, p=0.04), and more likely to be married and have higher educational attainment.
Conclusion:
Tub entry was influenced by the well-being of the laboring person and their pain management decisions, while giving birth in the tub was influenced by sociodemographic characteristics. Future work should evaluate how labor support, clinical decision-making, and structural factors shape equitable access to waterbirth.
Presentation Notes
Presented at Scientific Day; May 20, 2026; Milwaukee, WI.
Full Text of Presentation
wf_yes
Document Type
Oral/Podium Presentation
Characteristics Associated with Tub Entry and Delivery in Water: A Secondary Analysis of Waterbirth Intervention Participants
Background/Significance:
Waterbirth is a pain management option that promotes physiological birth with limited availability in US hospitals. We conducted the first US-based randomized controlled trial (RCT) of hospital waterbirth, finding it was a viable option for low-risk individuals and reduced use of intravenous narcotics and epidural analgesia while increasing satisfaction. To further support person-centered care, it is important to understand which individuals who planned waterbirth ultimately gave birth in water and how preferences and medical needs shifted during labor.
Purpose:
To identify factors linked to waterbirth tub use during labor and successful delivery in water among those planning a waterbirth.
Methods:
We conducted a secondary analysis of participants who were consented and assigned to the waterbirth arm of our RCT, 1/2022-12/2023. Waterbirth participants were offered standard intrapartum care along with the option of waterbirth. We explored tub entry and delivery in water, examining differences in age, pre-gravid BMI, gestational age, cervical dilation, induction, parity, marital status, race and ethnicity, and educational attainment. Fisher’s exact tests were used for categorical variables; Kruskal–Wallis tests for continuous variables. P values < 0.05 were statistically significant.
Results:
Of 116 waterbirth participants, 68 (58%) entered the tub. Hypertension (n=20) and desire for epidural anesthesia (n=10) were common reasons for not entering the tub. Of those who entered the tub, 41 (61%) gave birth in water. Common reasons for leaving the tub were for epidural analgesia (n=14), required cesarean or operative vaginal birth (n=6). When compared to those who did not enter the tub, tub entrants had a higher gestational age (39.7 vs 38.9 weeks, p<0.01), greater cervical dilation at admission (4.3 vs 2.0 cm, p<0.01), and were less likely to be nulliparous (38% vs 90%, p<0.01). Among tub entrants, those who gave birth in water had greater dilation at admission (4.8 vs 3.6 cm, p=0.02), were older (31.2 vs 27.5 years, p=0.01), less likely to be nulliparous (27% vs 56%, p=0.04), and more likely to be married and have higher educational attainment.
Conclusion:
Tub entry was influenced by the well-being of the laboring person and their pain management decisions, while giving birth in the tub was influenced by sociodemographic characteristics. Future work should evaluate how labor support, clinical decision-making, and structural factors shape equitable access to waterbirth.
Affiliations
Aurora UW Medical Group, Aurora Sinai Medical Center, Advocate Aurora Research Institute