A Cohcrane review included 10 studies with a total of 11 795 women. The studies compared the effects of an alternative institutional maternity care setting to conventional hospital care. No trials of freestanding birth centres or Snoezelen rooms were found. Allocation to an alternative setting increased the likelihood of: no intrapartum analgesia/anaesthesia (RR 1.18, 95% CI 1.05 to 1.33; 6 studies, n=8 953); spontaneous vaginal birth (RR 1.03, 95% CI 1.01 to 1.05; 8 studies, n=11 202); breastfeeding at six to eight weeks (RR 1.04, 95% CI 1.02 to 1.06; 1 study, n=1 147); and very positive views of care (RR 1.96, 95% CI 1.78 to 2.15; 2 studies, n=1 207). Allocation to an alternative setting decreased the likelihood of epidural analgesia (RR 0.82, 95% CI 0.74 to 0.87; 8 studies, n=10 931); oxytocin augmentation of labour (RR 0.77, 95% CI 0.67 to 0.88, statistical heterogeneity I2=61%; 8 studies, n=11 131); instrumental vaginal birth (RR 0.89, 95% CI 0.79 to 0.99; 8 trials, n = 11 202); and episiotomy (RR 0.83, 95% CI 0.77 to 0.90; 8 studies, n=11 055). There was no apparent effect on perinatal mortality (RR 1.67, 95% CI 0.93 to 3.00; 7 studies, n= 10 095), serious perinatal morbidity/mortality (RR 1.17, 95% CI 0.51 to 2.67, statistical heterogeneity I2=66%; 5 studies, n= 6 385), serious maternal morbidity/mortality (RR 1.11, 95% CI 0.23 to 5.36; 4 studies, n= 6 334), other adverse neonatal outcomes, or postpartum hemorrhage. No firm conclusions could be drawn regarding the effects of variations in staffing, organizational models, or architectural characteristics of the alternative settings.
Comment: The quality of evidence is downgraded by study limitations and by inconsistency (heterogeneity in interventions). In addition, the low number of women allocated to alternative settings who actually gave birth in their allocated setting serves to dilute both the potential benefits and risks of alternative settings.