Model of Care and Chance of Spontaneous Vaginal Birth: A Prospective, Multicenter Matched-Pair Analysis From North Rhine-Westphalia

Abstract

BackgroundCompared to standard obstetric care, advantages of midwife-led models of care have been reported; these include a higher vaginal birth rate and less interventions. In Germany, 98.4% of women are giving birth in consultant-led obstetric units. We compared the outcome of birth planned in alongside midwifery units (AMU) in North Rhine-Westphalia (NRW) with a matched group of low-risk women who gave birth in standard obstetric care during the same period of time.MethodsA prospective, controlled, multicenter study was conducted. Six of the seven AMUs in NRW participated. Healthy women with a singleton term cephalic pregnancy booking for birth in AMU were eligible. For each woman in the study group a control was chosen who would have been eligible for birth in AMU but was booking for standard obstetric care at the same hospital at the same time; additionally, matching for parity was performed. Mode of birth was chosen as primary outcome parameter. Secondary endpoints included a composite outcome of abnormal third stage and / or postpartum hemorrhage; higher-order obstetric lacerations; and for the neonate, a composite outcome (5-minute Apgar <7 and / or umbilical cord arterial pH < 7.10 and / or transfer to specialist neonatal care). Statistical analysis was by intention to treat. A non-inferiority analysis was performed for the primary and all secondary endpoints.Results589 case-control pairs were recruited, corresponding to 13.6% of those assumed to be eligible; 198 cases were excluded. Final analysis was performed with 391 case-control pairs. Nulliparous women constituted 56.0% of cases. For the primary endpoint vaginal birth superiority was established for the study group (5.66, 90%-CI 1.26-10.04). Superiority was also confirmed for higher-order obstetric lacerations (2.33, 90%-CI 0.04-4.81). For the composite newborn outcome non-inferiority was established (1.28, 90%-CI 1.33-3.93). Non-inferiority was not present for the composite maternal outcome (-1.56, 90%-CI -5.86-2.75). The epidural anesthesia rate was lower (22.9% vs. 41.1%), and the length of hospital stay was shorter in the study group (p<0.001 for both).Transfer to standard obstetric care occurred in 51.2% of cases, with a strong association between parity and transfer (p<0.001). Request for regional anesthesia was the most common cause for transfer (47.1%). ConclusionOur comparison between care in AMU and standard obstetric care with respect to mode of birth and other outcomes confirmed the superiority of this model of care for low-risk women. Admission and transfer criteria were in place in all participating centers and strictly adhered to.