Objective: This study investigated maternal and fetal outcomes following
warm water immersion (WWI) and/or waterbirth compared with land birth
for women with moderate obstetric risk factors. Design: Prospective
cohort study. Setting: Maternity hospital, Australia, 2019-2020
Population: 1665 participants, some with ‘risk factors’ for adverse
perinatal outcomes requiring continuous electronic fetal monitoring
(CEFM) during labour. Method: Multivariate logistical regressions were
used to determine the odds of neonatal and maternal outcome measures
between three groups: waterbirth, WWI and land birth Main outcome
measures: Neonatal morbidity and mortality, including neonatal unit
admission (NNU). Maternal clinical outcome measures, including mode of
birth, perineal injury, postpartum haemorrhage, length of labour and
morbidity. 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, previous birth mode, and
labour onset, no significant difference was detected between land births
and WWI/water births in the odds of NNU admission (p=0.200). No babies
were admitted to NNU with signs of water inhalation or drowning. Women
birthing on land had a higher mean blood loss (p=0.036) and were more
likely to be febrile (2% v 0%; p=0.007); Obstetric anal sphincter
injury was similar between groups. Pharmacological analgesia use was
lower in the WB/WWI group (p<0.001). There was 1 cord avulsion
in the waterbirth group (0.41%). Mode of birth was similar between
groups (p=0.697). Conclusion: Despite moderate obstetric risk factors
such as oxytocin administration and induction of labour; maternal and
neonatal outcomes were similar between groups.