A prospective cohort study comparing neonatal outcomes of waterbirth and land birth in an Australian tertiary maternity unit

Background: Maternal preference for warm water immersion (WWI) and waterbirth is increasing, but adoption into obstetric guidelines and clinical practice remains limited. Concerns regarding safety and a paucity of evidence have been cited as reasons for the limited adoption and uptake. Aim: The aim was to investigate maternal and neonatal outcomes after WWI and/or waterbirth compared with land birth. Materials and methods: A prospective cohort study was conducted in an Australian public maternity hospital between 2019 and 2020. Maternal and neonatal outcomes for 1665 women who had a vaginal birth were studied. Primary outcome was admission to the neonatal unit (NNU). Secondary outcomes included neonatal antibiotic administration, maternal intrapartum fever, epidural use and perineal injury. Multivariate logistical regression analyses compared the outcomes between three groups: waterbirth, WWI only and land birth. Results: NNU admissions for a suspected infectious condition were significantly higher in the land birth group (P = 0.035). After accounting for labour duration, epidural use and previous birth mode, no significant difference was detected between groups in the odds of NNU admission (P = 0.167). No babies were admitted to NNU with water inhalation or drowning. Women birthing on land were more likely to be febrile (2 vs 0%; P = 0.007); obstetric anal sphincter injury and postpartum haemorrhage were similar between groups. Regional analgesia use was significantly lower in the WWI group compared to the land birth group (21.02 vs 38.58%; P = <0.001). There was one cord avulsion in the waterbirth group (0.41%). Conclusion: Maternal and neonatal outcomes were similar between groups, with no increased risk evident in the waterbirth and WWI groups.