Pregnancy outcome at term in low-risk population: study at a tertiary obstetric hospital

The aim of this study was to evaluate the risk of perinatal death and peripartum morbidity at term amongst the models of care at a single tertiary hospital.

This is a 10-year population study of singleton births at term at the Mercy Hospital for Women comparing the mixed-risk models of care (private obstetrician and a conventional collaborative model of obstetricians and midwives) with the low-risk models (team midwifery and family birth center). Outcome measures included rates of perinatal death, low Apgar scores and obstetric procedures.

Data on 44 557 normal term singletons were available for study. Overall, the hospital has a substantially lower term singleton perinatal mortality (1.3/1000) than the reported rate from the state of Victoria over an overlapping period (2.4/1000). The perinatal mortality amongst women selected for low obstetric risk (2.3/1000) was significantly higher than the perinatal mortality in other patients (1.2/1000; P = 0.03). Low Apgar scores at 5 min were also significantly more likely in women selected for low obstetric risk (9.0 vs 6.7/1000; P = 0.03). The differences could not be attributed to socioeconomic status, as this was higher in the low obstetric risk group. Obstetric procedures (induction of labor, cesarean section and instrumental birth) were substantially less common in the low-risk-care patients, as is expected for a low-risk population.

Women selected for low-risk under midwife-led models of care do not appear to have better outcomes than women with all levels of perinatal risk cared for under traditional obstetrician-led models of care.