Characteristics Associated With Tub Entry and Birth in Water Among People Planning a Waterbirth

Waterbirth is a pain relief option and a comfort measure not widely available in US hospitals. This study presents a secondary analysis of a randomized control trial of waterbirth examining participants' entry into the tub and final location of birth (water or non-water) to determine characteristics associated with successful waterbirth.

We analyzed data from a hospital-based waterbirth study that was conducted at a large, urban, midwestern medical center. Among those planning a waterbirth who presented in labor at term, we compared participant and labor characteristics by tub entry during labor and completion of birth in water using Fisher's exact and Kruskal-Wallis tests.

Of 124 participants randomized to waterbirth, 96 were eligible for inclusion in this analysis, with 68 (71%) entering the tub during labor and 41 (43%) giving birth in water. Common reasons for not entering the tub included hypertension (n = 10) and desire for epidural analgesia (n = 10). Of those who entered and subsequently left the tub, 14 desired epidural analgesia and 4 required cesarean or operative vaginal birth. Participants who enterefd the tub had greater cervical dilatation at admission (4.3 vs 2.6 cm, P < .001). Those who entered the tub and gave birth in water were older (31.2 vs 27.5 y, P = .012), had greater dilatation at hospital admission (4.8 vs 3.6 cm, P = .023), and were more likely to be multiparous (56% vs 27%, P = .023). Participants who gave birth in water were also more likely to be married and have higher educational attainment.

Medical contraindications emerging after admission highlight labor unpredictability and the importance of ongoing assessment for waterbirth eligibility. Although characteristic differences related to tub entry were primarily physiologic, those related to giving birth in the tub also included sociodemographic differences. Future work should evaluate how labor support, clinical decision‑making, and structural factors shape equitable access to waterbirth.