September 03, 2019
Research Review: Systematic Review Finds No Increase in Adverse Outcomes with Planned Home Birth
By: Henci Goer, BA | 0 Comments
The great difficulty of attempting to determine comparative perinatal and neonatal mortality with home vs. hospital birth is amassing a large enough dataset of appropriately designed studies. In their review, “Perinatal or neonatal mortality among women who intend at the onset of labour to give birth at home compared to women of low obstetrical risk who intend to give birth in hospital: A systematic review and meta-analyses,” Hutton & colleagues (2019) overcome these difficulties with an ingenious study selection and analysis strategy. They began by restricting included studies to those in which:
- Women planned home birth at the onset of labor,
- Intention to birth at home was confirmed or reconfirmed at labor onset,
- There was a comparison group of similarly low-risk women planning hospital birth,
- 0utcomes were reported according to planned place of birth, not actual place of birth (intent to treat),
- Investigators accounted for first births vs. previous births (parity), and
- The planned home birth group represented all home births, or investigators accounted for missing cases.
Included were 17 studies comprising 500,000 births of which 14 had data that could be included in meta-analyses (analysis of data pooled from multiple studies) of perinatal (intrapartum death + 7 days after birth) and neonatal (death between day 0 and day 28 in a liveborn infant) death in babies free of congenital anomalies.
The review’s original intent was to compare low-risk women planning home vs. hospital birth, however, in actual practice, some studies included all planned home births regardless of whether they would be considered eligible for home birth according to local standards. For this reason, reviewers categorized studies into one of two study designs. One design, which they deemed “pragmatic,” answered the research question: “Do women who intend at the onset of labor to give birth at home experience a higher or lower incidence of fetal or neonatal loss compared to women at low obstetric risk who intend at the onset of labor to give birth in hospital?” These studies included all women intending home birth within the study’s time frame regardless of whether they were considered eligible by the community’s standards. The other, called “within standards,” answered the question: “Do women who intend to give birth at home and who meet their local eligibility criteria for home birth at the onset of labor experience a higher or lower incidence of fetal or neonatal loss compared to women who meet their local eligibility criteria for home birth but intend at the onset of labor to give birth in hospital?” This design would exclude, for example, twin or breech births if they were contrary to local community standards regardless of whether the birth was planned to be at home at labor onset whereas the pragmatic design would not.
Reviewers also explored the degree of support for home birth as a factor potentially impacting perinatal outcomes. They divided included studies into “well-integrated” vs. “less well-integrated” systems in which “well-integrated” was defined as “a place where home birth practitioners: are recognized by statute within their jurisdiction; have received formal training; can provide or arrange care in hospital; have access to a well-established emergency transport system, and carry emergency equipment and supplies.” “Less well-integrated” systems lacked one or more of these characteristics.
The reviewers performed five meta-analyses:
- “Perinatal or Neonatal Mortality: Integrated Setting, Nulliparous Women,” i.e., no prior births
- “Perinatal or Neonatal Mortality: Integrated Setting, Multiparous Women,” i.e., prior births
- “Perinatal or Neonatal Mortality: Integrated Setting, Not Stratified by Parity,” meaning investigators adjusted outcomes for parity but didn’t report nulliparous and multiparous outcomes separately
- “Perinatal or Neonatal Mortality: Not Well Integrated Setting, Nulliparous Women”
- “Perinatal or Neonatal Mortality: Not Well Integrated Setting, Multiparous Women”
Within each meta-analysis, results of pooled data from “Standards Met” and “Pragmatic” studies were reported both separately and as a combined total. Combining the two subsets increased sample size, strengthening the ability to detect differences between planned home and hospital birth. Reviewers also repeated their meta-analyses excluding studies with large datasets to make sure conclusions were not overshadowed by results from a single study.
What Did the Reviewers Find?
Not one meta-analysis, whether a subset analysis or a combined analysis, found an excess of perinatal or neonatal mortality with planned home birth compared with a low-risk hospital population. Results held when a large Dutch study was removed from the calculation. Two studies that reported their findings as risk ratios rather than odds ratios couldn’t be included in the meta-analysis. One had similar results to the meta-analyses. The other, the sole American study included in the review (Pang 2002), reported excess deaths in the group planning home birth. A critique of this study, however, disputes whether the study fits the review’s inclusion criteria (Vedam 2003). Among other weaknesses, it argues that the birth certificate data Pang et al. used as their source was not capable of distinguishing between planned and unplanned home births.
In addition to the mortality meta-analyses, reviewers summarize results of meta-analyses of infant morbidity findings. As with mortality, no excesses were found for neonatal resuscitation or admission to neonatal intensive care in women planning home birth. In fact, multiparous women planning home birth were 27% less likely to have an infant admitted to intensive care.
There is, however, a caveat. The reviewers note that their results may have been biased in favor of home birth because home birth studies occurring in less well-integrated settings were more likely to have been excluded from the review, and these studies may have had higher adverse outcomes rates in the home birth population. They add that while their meta-analyses found no statistically significant differences in mortality with planned home birth in less well-integrated settings, meaning that any excess was probably due to chance, there was a trend that favored planned hospital birth.
What Conclusions Can We Draw?
First, the best evidence we have to date vindicates home birth. Planned home birth did not confer excess perinatal risk even though some women in the home birth studies were not low risk but were compared with low-risk women planning hospital birth and despite some home birth studies being conducted in maternity care systems that are not well integrated.
Conclusion: Planned home birth is a reasonable option that should be available to childbearing women as part of the maternity care system.
Second, this vindication is not a reason for complacency. The reviewers warn that they may not have detected the impact of the deficiencies of a poorly integrated system.
Conclusion: To achieve optimal outcomes, home birth practitioners should be integrated into the maternity care system.
Third, maternity care systems must address the root causes of why at-risk women choose home birth. One obvious reason is denial of the option to birth vaginally in women with prior cesarean or who have a breech baby or twins or where vaginal birth in these cases is so hedged in with non-evidence-based restrictions and negative attitudes that it amounts to the same as a denial. Another is rejection of hospital birth by women who are unhappy with their treatment at a previous birth, an occurrence that is all too common (Vedam 2019).
Conclusion: Maternity care systems should provide safe, evidence-based, humane hospital care that is respectful of the right of childbearing women to make decisions about their care.
Pang, J. W., Heffelfinger, J. D., Huang, G. J., Benedetti, T. J., & Weiss, N. S. (2002). Outcomes of planned home births in Washington State: 1989-1996. Obstetrics and Gynecology, 100(2), 253-259.
Vedam, S., Stoll, K., Taiwo, T. K., Rubashkin, N., Cheyney, M., Strauss, N., . . . Council, G. VtM-US Steering. (2019). The Giving Voice to Mothers study: inequity and mistreatment during pregnancy and childbirth in the United States. Reprod Health, 16(1), 77. doi:10.1186/s12978-019-0729-2
Vedam, S. (2003). Home birth versus hospital birth: questioning the quality of the evidence on safety. Birth, 30(1), 57-63.
About Henci Goer
Henci Goer, award-winning medical writer, and internationally known speaker is an acknowledged expert on evidence-based maternity care. Her first book, Obstetric Myths Versus Research Realities, was a valued resource for childbirth professionals. Its successor, Optimal Care in Childbirth: The Case for a Physiologic Approach, won the American College of Nurse-Midwives “Best Book of the Year” award. Goer has also written The Thinking Woman's Guide to a Better Birth, which gives pregnant women access to the research evidence, as well as consumer education pamphlets and articles for trade, consumer, and academic periodicals; and she posts regularly on Lamaze International’s Connecting the Dots. Goer is founder and director of Childbirth U, a website offering narrated slide lectures to help pregnant women make informed decisions and obtain optimal care for themselves and their babies.
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