New Home Birth Studies

By Rachel Walden — September 8, 2009

Two recent studies of home birth have generated a lot of attention online.

The first (.pdf), published in the British Journal of Obstetrics and Gynaecology, examines fetal and newborn outcomes of planned home and planned hospital births among low-risk women.

For this retrospective study, the authors identified all low-risk women (more than 500,000 of them) who gave birth in the years 2000-2006 in Netherlands and who were in midwife-led care at the onset of labor. They explain that in the Netherlands, independent primary care midwives care for low-risk pregnant women, but women are transferred to “secondary” care with an obstetrician if any risks arise during pregnancy, or to a hospital if problems occur during a planned home birth.

Approximately 30% of women in the Netherlands give birth at home. The authors compared women by intended place of birth (home, 60.7%; hospital, 30.8%; or unknown, 8.5%) for intrapartum fetal death, intrapartum and neonatal death up to 24 hours, and intrapartum and neonatal death up to 7 days and admission after birth to a neonatal intensive care unit (NICU).

Women were included as low risk if they gave birth at 37-42 weeks gestation to a single fetus, with no known medical or obstetric risk factors, cephalic (head down) presentation, no previous c-section, no previous postpartum hemorrhage, no prolonged (>24 hours) rupture of membrane, no congenital abnormality, and no intrauterine death prior to onset of labor. Women not meeting these criteria were not considered low risk and so were not included. Included women who planned a home birth may have been transferred to a hospital for reasons such as failure to progress, an abnormal fetal heart rate pattern, or meconium staining.

The authors explain that after controlling for confounding factors (maternal and gestational age, parity, ethnic background, and socioeconomic status), there was no significant difference between groups on measures of perinatal mortality, and no significant difference between planned home vs. planned hospital groups on risk of NICU admission.

The authors note that the study has some limitations, including its retrospective design and missing NICU data for 50% of the non-teaching hospitals. It’s strengths are its very large size, available national registry data, and comparison of groups of women who were considered low risk until the onset of labor, rather than comparing low-risk women planning home births to mixed hospital birth populations that include known high risk patients (i.e., those who were never candidates for home birth).

An editorial on the paper notes that the approach to maternity care in the Netherlands is rather different from that in some other locations, explaining that “maternity services in the Netherlands are set up to meet the demand for home births, transport is good, and distances short,” but also calls the large study “reassuring about the relative safety of planning home births if women are low risk.

Jennifer Block (“Pushed”) wrote about this study and home birth in general last month for Babble, and the UK’s National Health Service offers this summary.

A recent retrospective cohort study, published in the Canadian Medical Association Journal, was conducted in British Columbia, Canada, and compared 2,889 planned home births attended by registered midwives to planned hospital births attended by registered midwives (4,752) or physicians (5,331). Women planning to give birth at home had to be medically eligible for home birth at the onset of labor. These eligibility criteria excluded women with certain pre-existing conditions (such as heart disease), pregnancy-related diseases such as gestational diabetes requiring insulin and hypertension, multiple fetuses, non-cephalic presentation, premature or post-dates pregnancies (<36 or >42 weeks), >1 previous c-section, and other factors. The planned hospital births included in the study also met the home birth eligibility criteria.

The authors’ primary outcome of interest was the rate of perinatal death, defined as stillbirth after 20 weeks’ gestation or death in the first 7 days of life, although stillbirths occurring before the onset of labor or in women who gave birth before 37 weeks were excluded from all groups.

The outcomes were analyzed by planned place of birth. Specific information on reasons for transfer does not seem to be available, but 78.8% of those women who planned a home birth with a midwife had one, and 96.9% of those who planned to be attended by a midwife in a hospital did so.

The authors found no statistically significant differences in the low risk of perinatal mortality between the 3 groups, at 0.35/1,000 for planned home birth, 0.57/1,000 for planned hospital birth with a midwife, and 0.64/1,000 for planned hospital birth with a physician. There were no deaths from 8-28 days of life. The authors also observed lower rates of obstetric interventions for planned home births with midwives than with either hospital group – the full text with tables of these secondary outcomes is freely available online.

The authors note the ability to compare place of birth without confounding from the type of provider (assuming physicians are more likely to conduct interventions than midwives), a strength of the Dutch study as well. But the authors also explain that “our findings do not extend to settings where midwives do not have extensive academic and clinical training.” They also note the possibility that some unknown difference between groups that influenced choice of birth place may have affected the outcomes, but that “our data indicate that screening for eligibility by registered midwives can safely support a policy of choice of birth setting.”

Amy Romano at Science & Sensibility and Lauredhel at Hoyden About Town have both written about the study, with a fair bit of discussion at both places.

Citations: de Jonge A, van der Goes BY, Ravelli AC, Amelink-Verburg MP, Mol BW, Nijhuis JG, Bennebroek Gravenhorst J, Buitendijk SE. Perinatal mortality and morbidity in a nationwide cohort of 529,688 low-risk planned home and hospital births. BJOG. 2009 Aug;116(9):1177-84.

Janssen PA, Saxell L, Page LA, Klein MC, Liston RM, Lee SK. Outcomes of planned home birth with registered midwife versus planned hospital birth with midwife or physician. CMAJ. 2009 Aug 31. [Epub ahead of print]

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