Objective To review randomised controlled trials of alternative maternity services characterised by continuity of midwifery care.
Methods A systematic review of randomised controlled trials, analysed on an intention to treat basis, in which the study intervention was characterised by a midwife or small group of midwives providing care from early pregnancy to the postnatal period (defined as that provided on the postnatal ward); and the controls by standard maternity care as practised in the place where the trial was conducted. The seven trials identified included 9148 women. Main outcome measures were interventions during labour, maternal outcomes and infant outcomes.
Results The alternative models with continuity of midwifery care were associated with less use of obstetric interventions during labour (eg, induction, augmentation of labour, electronic fetal monitoring, obstetric analgesia, instrumental vaginal delivery and episiotomy). However, the caesarean section rate did not differ statistically between the trial groups (OR 0.91; 95% CI 0.78 to 1.05). The lower episiotomy rate in the alternative models of care (OR 0.69; 95% CI 0.61 to 0.77) was associated with a significantly higher rate of perineal tears in the pooled alternative groups (OR 1.15; 95% CI 1.05 to 1.26). The percentage of intact perineums was very similar for the two groups (OR 1.11; 95% CI 1.00 to 1.24). There was no maternal death, and rates of maternal complications based on unpooled estimates did not show any statistically significant differences. The proportion of babies with an Apgar score < 7 at five minutes after the birth was approximately the same in the pooled alternative groups as in the control groups (OR 1.13 95% CI 0.69 to 1.84). Admission to intensive care or special care baby unit was similar (OR 0.86; 95% CI 0.71 to 1.04). The difference in perinatal deaths was bordering on statistical significance (OR 1.60; 95% CI 0.99 to 2.59).
Conclusion Continuity of midwifery care is associated with lower intervention rates than standard maternity care. No statistically significant differences were observed in maternal and infant outcomes. However, more research is necessary to make definite conclusions about safety, for the infant as well as for the mother. This review illustrates the variation in the different models of alternative and standard maternity care, and thus the problems associated with pooling data from different trials.