Maternal and perinatal outcomes amongst low risk women giving birth in water compared to six birth positions on land : a descriptive cross sectional study in a birth centre over 12 years

Background: the option of giving birth in water is available to most women in birth centres in Australia but there continues to be resistance in mainstream delivery wards due to safety concerns. Women in birth centres are more likely to give birth in upright positions and be attended by experienced midwives and obstetricians who are comfortable facilitating normal birth. The aim of this study was to determine rates of perineal trauma, postpartum haemorrhage and five-minute Apgar scores amongst low risk women in a birth centre who gave birth in water compared to six birth positions on land. Methods: this was a descriptive cross sectional study of births occurring in a large alongside Sydney birth centre from January 1996 to April 2008. Handwritten records were kept by midwives on each birth in the birth centre over twelve and a half years (n=6,144). Descriptive statistics and logistic regression were applied controlling for risk factors for perineal trauma, postpartum haemorrhage and the five-minute Apgar score. Findings: waterbirth (13%) and six main birth positions on land were identified: kneeling/all fours (48%), semi-recumbent (12%), lateral (5%), standing (8%), birth stool (10%) and squatting (3%). Compared to waterbirth, birth on a birth stool led to a higher rate of major perineal trauma (second, third, fourth degree tear and episiotomy) (OR 1.40 [1.12-1.75]) and postpartum haemorrhage (OR 2.04 [1.44-2.90]). Compared to waterbirth, babies born in a semi-recumbent position had a significantly greater incidence of five-minute Apgar scores <7 (OR 4.61 [1.29-16.52]). Conclusions: waterbirth does not lead to more infants born with Apgar score <7 at 5. mins when compared to other birth positions. Waterbirth provides advantages over the birth stool for maternal outcomes of major perineal trauma and postpartum haemorrhage.