Self-rated ‘no’ and ‘low’ risk pregnancy: a comparison of outcomes for women in obstetric-led and midwife-led units in England

Background: Debate in the United Kingdom about place of birth often concerns obstetric-led units and midwife-led units and relates to notions of risk and safety. Outcomes for these two types of unit are often not comparable because of the restricted selection criteria for midwife-led units. The purpose of this study was to compare outcomes for women intending to give birth in these different types of unit and whose self-rated pregnancy risk level was “none” or “low.” Methods: Self-completion questionnaires were distributed to mothers 8 days after the birth in 9 units (6 midwife led 3 obstetric led) over a 6-month period.Results: Completed questionnaires were received from 432 women (midwife led = 294, obstetric led = 138). Mothers in midwife-led units spent shorter times in labor in the unit (p < 0.01), received less analgesia (p < 0.01) and had fewer interventions (p < 0.01), and were more likely to have a normal delivery (p < 0.01) than women in obstetric-led units. Similar differences were found for both primiparous and multiparous women. In terms of the number of midwives attending each woman, analysis of covariance suggested different models of care depending on type of unit (p < 0.05) and parity (p < 0.01).Conclusions: Since these mothers’ self-rated risk level was none or low, some comparability of outcomes is permissible. It appears that models of care are significantly different in obstetric-led units compared with midwife-led units, leading to greater likelihood of intrapartum intervention, need for analgesia, and assisted or operative delivery. A randomized controlled trial examining such units would permit a conclusive examination of these outcomes.