Perinatal Adverse Event Rates Appear Similar in Most Women with Low-Risk Pregnancies Regardless of Planned Birth Setting, But May Be Higher for Home Births in First Pregnancy

DynaMed Weekly Update - Volume 6, Issue 48

Planned births at home and in midwife units have been shown to reduce interventions during labor compared to hospital obstetric units, but good quality data to assess the risk of serious adverse outcomes for different planned birth locations have been lacking (NICE 2007 Sep:CG55). A recent prospective cohort study assessed the rates of perinatal adverse events occurring in low-risk pregnancies over a 2-year period (2008-2010) in England at different planned locations at start of care in labor. The population included all women attended by a midwife provided by the National Health Service with planned birth at home, at a freestanding midwifery unit, or at a midwife-led unit in a hospital. Outcomes for these women were compared to a cohort of randomly chosen women with planned birth at conventional obstetric units.

A total of 64,538 singleton pregnancies were assessed (16,840 women in home settings, 11,282 in freestanding midwifery units, 16,710 in midwife-led units in hospitals, and 19,706 in hospital obstetric units). The primary outcome was a composite of perinatal mortality and intrapartum-related neonatal morbidities (stillbirth after start of care in labor, early neonatal death, neonatal encephalopathy, meconium aspiration syndrome, brachial plexus injury, and fractured humerus or clavicle). In an overall analysis, planned birth locations did not significantly affect adverse perinatal outcomes per 1,000 births (4.2 for home setting, 3.5 for freestanding midwifery units, 3.6 for midwife-led units in hospitals, 4.4 for obstetric units) (level 2 [mid-level] evidence). Adverse event rates were generally higher for nulliparous women than for multiparous women. There were no significant differences in adverse event rates in multiparous women, but home birth was associated with a higher rate (9.3 per 1,000 births, p < 0.05) compared to other locations in nulliparous women (4.5 for freestanding midwifery units, 4.7 for midwife-led units in hospitals, 5.3 for obstetric units). Planned birth in obstetric units was associated with an increased rate of intervention during labor compared to other locations (BMJ 2011 Nov 23;343:d7400).

For more information, see the Overview of labor and delivery topic in DynaMed.