Place of delivery and adverse outcomesBMJ 2010; 341 doi: https://doi.org/10.1136/bmj.c5560 (Published 03 November 2010) Cite this as: BMJ 2010;341:c5560
Planned birth at home or in a midwifery unit is part of the choice that should now be offered to women at low risk of complications. A recent large meta-analysis of mostly cohort studies (500 000 births) showed a doubling of the risk of excess neonatal deaths for home birth from 0.09% to 0.2%—one extra death in 900 births.1 However, the risks associated with birth in different settings are still uncertain because of the confounding factors inherent in observational data. These include differences in baseline risk, the intended or actual place of birth, demographics, parity, and standards of care. One randomised trial was piloted, but it looked at only 11 women⇓.2
In the linked prospective cohort study (doi:10.1136/bmj.c5639), Evers and colleagues compared incidence rates of perinatal mortality and severe perinatal morbidity in the infants of low risk women who started labour in primary care (under a midwife) and high risk women who were under the care of obstetricians in hospital.3 The Netherlands, where the study was set, has an unusually high rate of women planning to give birth at home (33%), and a higher than average perinatal mortality.4 The authors found that low risk women under the care of a midwife have a significantly higher risk of intrapartum related perinatal death than high risk women under the supervision of an obstetrician (relative risk 2.33, 95% confidence interval 1.12 to 4.83). The difference in risk would account for one extra death in 1250 home births (comparable to the meta-analysis). The authors highlight potentially inadequate risk assessment and suggest the difference in outcome may be because women were inappropriately booked for labour care under a midwife. Risk assessment is an inexact science, however.
The benefits of planned birth at home or in a midwifery unit mainly affect the mother. Such benefits, including a reduction in caesarean section and instrumental vaginal birth, must be considered against any assessment of risk.5 Also the size of any increased risk of an adverse perinatal outcome has to be placed in the context of other risks that women commonly accept in pregnancy, such as vaginal birth after caesarean section. In the Dutch study, the increased risk in the home birth group was still only comparable to that of a woman having vaginal birth after caesarean section in a consultant led unit.6 Therefore, women may reasonably choose home or midwifery led birth because of its potential benefits, even if the risk of an adverse perinatal outcome is increased.
What are the possible reasons for an increase in adverse perinatal outcomes? Serious adverse events in labour are uncommon in any setting. Obviously, however, if such an event does occur, the further away from assistance a woman is the less likely the outcome will be good. Proponents of home birth suggest that by avoiding other interventions (such as electronic monitoring, immobility, and oxytocin) these adverse outcomes are reduced. Whatever the reality, it is clear that to minimise adverse outcomes early recognition of a problem is necessary and this requires an acceptance by women and those caring for them that there is a risk of an adverse outcome at any birth. Low risk does not equal no risk, and high risk women who are away from consultant care are at particular risk. The systems need to identify problems, implement techniques to resolve them in different birth settings, and, if necessary, instigate prompt referral and assessment in an obstetric unit.
Probably most women will still choose to give birth in an obstetric unit, often because of the availability of epidural analgesia. The presence of risk factors means that many women would be strongly advised to give birth in an obstetric unit. Although one to one care is recommended for all births, it is by no means routinely achieved in hospital because of staffing levels and peaks in demand. Interestingly, women are often supported by two midwives at a home birth, which may be why some women choose it. At an individual level this is understandable, but it adds an extra dimension to service provision.
The Birthplace Cohort Study of Low Risk Birth will provide additional data on fetal mortality and morbidity, in addition to rates of caesarean section, later this year and will stir the waters further.7 Although it is welcome, as a cohort study it can provide only estimates of several conflicting maternal and neonatal outcomes. The debate will continue and women will have to make individual choices. Clinicians, commissioners, and providers of services will have to understand how those choices are supported within the provision of a maternity service as a whole.
Cite this as: BMJ 2010;341:c5560
Competing interests: All authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Provenance and peer review: Commissioned; not externally peer reviewed.