Participant sample and setting
A convenience sampling approach was taken. Within the Birthing Suite of
the XXXXXXXXX Hospital, all women intending a vaginal birth and eligible
to enter the birth pool (warm water immersion +/-water birth) between
April 2019 through to April 2020 were included. The study site is a
tertiary, publicly funded maternity unit with approximately 3600 births
per year, in a coastal region of Queensland Australia.
Inclusion criteria (which were guided by the local Workplace Instruction
on Warm Water Immersion and Water Birth (14)) were
applied, including:
- Consent to CEFM where recommended (for example induction of labour)
- Cephalic presentation
- Term gestation
- Not a carrier of, or infected with, HIV, Hepatitis B or C
- BMI <35
- Clear liquor (if membranes ruptured)
- No history of previous shoulder dystocia or severe postpartum
haemorrhage
- No suspected fetal macrosomia (fetal weight <4500g)
Exclusion criteria:
- Emergency caesarean section for current birth
- Antepartum haemorrhage
- Pre-eclampsia
- Abnormal CTG prior to or at any time during the warm water immersion
(Women were asked to leave the water, however, were still included in
analysis as WWI only group )
The initial aim of this study was to compare the outcomes of women who
birthed in water with those that had birthed on land. It is not possible
to have a waterbirth and a caesarean section, hence women who underwent
caesarean were excluded to ensure that we had homogeneity amongst the
two groups. Following data collection, it became clear that we should
evaluate labour outcomes amongst women who used WWI during labour but
did not have a waterbirth. We decided that caesarean sections would
continue to be excluded given that our primary area of interest was the
outcomes of women achieving vaginal birth. In addition, according to the
recent 2018 Cochrane Review, there is no evidence that WWI affects
caesarean section rates (6).