Comments on Wax Meta-analysis; list of PHB references from UK & EU
Comments:
It is always challenging to read a report which contradicts one’s deeply-held beliefs, but I have tried to be objective in my comments on this study. Here are some thoughts:
First of all, findings of Wax Meta-analysis contradict almost all other recent research on planned home birth; the consensus of the scientific literature (over a hundred peer-reviewed papers and other research data published since 1974) find have found no statistically significant difference in neonatal mortality and a dramatic reduction in the Cesarean section rate and the number of other medical and surgical interventions that the laboring woman was exposed to.
For example, the National Birthday Trust Fund study of around 6,000 planned home births in the UK found no difference in death rates, but a great reduction in complications and reductions in injuries to mother and baby when a home birth was planned.
Olsen’s meta-analysis of the safety of home birth looked at outcomes for a total of over 24,000 women, from six trials with good methodology, comparing planned home birth with planned hospital birth for women of similar risk levels. It found no difference in perinatal mortality rates, but improvements in other outcomes among the planned home births – eg fewer low APGAR scores and caesarean sections. We have to ask why the Washington State study found different results. Is something different about planned home birth in Washington State during the period studied, or was something different about the way this study was conducted?
I find it strange that the full text of the article mentions one Australian study which found worse outcomes for planned home birth (where the planned home births included a disproportionate number of high-risk births, and where the facilities for transfer to hospital were poor), and another study which found poorer outcomes for planned home births in Missouri, 1978-1984 which will be reviewed below. Yet, as noted above, it does not seem to mention any of the European studies which found good outcomes for planned home birth, despite these studies having sound methodology and being published in highly respected journals (eg see the British Medical Journal’s special edition on home birth). If the authors were restricting themselves to mentioning studies conducted in areas which were near Washington State, or which experienced similar conditions then this would be understandable – but no such rationale is given. Often when a research paper reaches drastically different conclusions from similar studies, there is an acknowledgement of this and a discussion of why this might have happened is offered – but there is none in this paper. In fact, the only other studies on home birth which seem to be explicitly mentioned in the text (as opposed to the references) are the very small number which produced relatively poor outcomes.
The methodology of this study, although understandable, is not as convincing as those of many other studies reviewed on this site. The authors attempted to guess which home births were planned retrospectively, by looking at birth outcomes for babies born out of hospital or for those born in hospital where there was some indication that a home birth was planned. This is in contrast to prospective studies such as the National Birthday Trust Fund study, where women planning a home birth were recruited into the study at 37 weeks of pregnancy, and the outcomes of their pregnancies were carefully recorded specifically to provide data for the study. The authors of the paper about home births in Washington State explain in the full text of the study that they tried to guess which births were planned home births by excluding results for all women who did not fulfil low-risk criteria. Yet in fact many women who plan home births are not strictly low-risk. Of course, it could be that home births in Washington State would perform worse still if the data were more accurate – but the point is that we do not have all the data which would be needed to make a full assessment.
Research Summaries – Page 3
Scroll down to read the studies, or use the index to jump to each individually.
1. Place of delivery: a review
By Campbell R, MacFarlane A
Br J Obstet Gynaecol 1986 Jul;93(7):675-83
‘The available evidence does not support claims that, for the baby, the iatrogenic risks of obstetric intervention outweigh the possible benefits. At the same time, there is no evidence to support the claim that the shift to hospital delivery is responsible for the decline in perinatal mortality in England and Wales nor the claim that the safest policy is for all women to be delivered in hospital.’
See Abstract of this study on Medline
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2. Home births in England and Wales, 1979: perinatal mortality according to intended place of delivery
by Campbell R, Davies IM, Macfarlane A, Beral V
Br Med J (Clin Res Ed) 1984 Sep 22;289(6447):721-4
Survey of all 8856 home births occurring at home in England and Wales in 1979. Found that planned home birth is much safer than accidental home birth, which is why statistics lumping together ‘home and out of hospital births’ are misleading. For instance, the perinatal mortality rate for planned home births in this study was 4.1 per thousand, but for unbooked births it was 196.6 per thousand. ‘..data suggest that the perinatal mortality among births booked to occur at home is low, especially for parous women’.
See Medline’s entry for this document
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3. The Safety of Home Birth: The Farm Study
by A. Mark Durand, MD, MPH,
Published in Am J Public Health, 1992;82:450-452
Data from an alternative community where home birth is the norm. The Farm has now become famous for midwifery, and is the home of Ina Mae Gaskin, author of ‘Spiritual Midwifery’.
‘Pregnancy outcomes of 1707 women, who enrolled for care between 1971 and 1989 with a home birth service run by lay midwives in rural Tennessee, were compared with outcomes from 14,033 physician- attended hospital deliveries derived from the 1980 US National Natality/National Fetal Mortality Survey. Based on rates of perinatal death, of low 5-minute Apgar scores, of a composite index of labor complications, and of use of assisted delivery, the results suggest that, under certain circumstances, home births attended by lay midwives can be accomplished as safely as, and with less intervention than, physician-attended hospital deliveries.’
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4. Five year prospective study of risk of booking for a home birth in Essex
By Shearer JM
Br Med J (Clin Res Ed) 1985 Nov 23;291(6507):1478-80
This study compared 202 women who booked home births with a similar group of women booked for hospital births. The hospital group had more episiotomies, second-degree tears, and more babies in the hospital group were in poor condition at birth (Apgar 7 or below). No deaths occurred in either group. The induction rate was 8% in the home group and 19% in the hospital group; it seems reasonable to assume that these women all transferred to hospital for induction. Presumably the lower induction rate before onset of labour could reflect more opposition to induction among women booking a home birth, and less pressure for induction from midwives.
‘The results of this study showed no evidence of an increased risk associated with home confinements but indicated that there were fewer problems than were encountered in the deliveries in mothers confined in hospital.’
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5. Licensed midwife-attended, out-of-hospital births in Washington State: are they safe?
By Janssen PA, Holt VL, Myers SJ
Birth 1994 Sep;21(3):141-8
This study found that it was just as safe to have a baby outside hospital, under the care of a licensed midwife, as to have a hospital delivery with doctors or Certified Nurse-Midwives in attendance.
The authors compared out-of-hospital births, attended by licensed midwives, to those attended by doctors and Certified Nurse-Midwives. Low birthweight, low Apgar scores, neonatal and postneonatal mortality were recorded. No significant differences in Apgar scores or mortality were noted. The out-of-hospital midwife deliveries were less likely to produce low-birthweight babies. Looking at only low-risk mothers, licensed midwives and certified nurse-midwives were both less likely to deliver low-birthweight babies than doctors. Similar results have been found in other studies, and personally I find this slightly confusing; how could the place of birth have any influence on the birthweight of the baby?
My guesses at possible reasons for this: premature babies are more likely to be delivered in hospital, by doctors, which would increase the number of low-birthweight babies in the hospital group. But confining results to low-risk women should remove most of these cases. Inductions are less common in home-birth bookings (see several studies above), which reduces the risk of accidental early delivery and hence low birthweight. If you have any other information on this subject, I would be pleased to hear from you.
The authors concluded that ‘The results of this study indicate that in Washington state the practice of licensed non nurse-midwives, whose training meets standards set by international professional organizations, may be as safe as that of physicians in hospital and certified nurse-midwives in and out of hospital. ‘
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6. Outcomes of 1001 midwife-attended home births in Toronto, 1983-1988
By H Tyson
Birth 1991 Mar;18(1):14-9
This study followed the progress of 361 first-time mothers and 640 multiparas (women who have given birth before) who planned home births.
Transfer rates: 92% of mothers having second or later babies gave birth at home, and 8% (51 women) transferred to hospital during labour or the first four days afterwards. 68% of first-time mothers stayed at home, and 32% (116 women) transferred; these figures are similar to those in the National Birthday Trust report. The most common reasons for transfer were long labours, long second stage, and membranes having been ruptured for a long time.
Among women who transferred to hospital, 34 had forceps deliveries, and 35 had caesareans. Out of 1001 women, the caesarean rate was therefore 3.5%!
One baby born at home died, and one baby born at hospital died. The overall mortality rate of 2/1001 was very low.
This study confirmed the excellent rates for breastfeeding after home birth which have been observed elsewhere. At 28 days, 98.6% of mothers were fully breastfeeding (ie no supplements). This is evidence that a relaxed start to family life helps establish breastfeeding.
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7. Outcome of planned home births in an inner city practice
Ford C, Iliffe S, Franklin O (Department of Primary Health Care, Whittington Hospital, London.)
BMJ 1991 Dec 14;303(6816):1517-9
The progress of 285 women who booked home births between 1977 and 1989 were followed for this study. 77.6% had normal births at home, 9.4% were transferred to specialist care during pregnancy, and another 9.4% transferred to hospital during labour. First-time mothers were more likely to transfer to hospital because of slow labour, but they were no more likely to transferred to specialist care during pregnancy. Postnatal complications for mother and baby were very rare after home birth, with only 4 mothers and 3 babies needing specialist attention.
The researchers concluded that ‘Birth at home is practical and safe for a self selected population of multiparous women, but nulliparous women are more likely to require transfer to hospital during labour because of delay in labour.’
Note that this study, like many others, did not find any evidence that home birth was unsafe for first-time mothers (‘nulliparas’ or ‘primigravidas’), just that they were more likely to transfer to hospital because of a long labour.
The abstract does not give details of the proportion of first-time mothers who transferred, but even if it was as high as the 40% in the National Birthday Trust study, that does not mean home birth is impractical for first-time mothers. How many hospitals can boast that 60% of their first-time mothers give birth naturally, with no interventions? The rate for planned home births is actually higher than that, because many women who transfer to hospital go on to give birth there with no major interventions, but only further observation or pain relief. Granted, some women who give birth at home will have interventions there – some women have their membranes ruptured at home, for instance – but this is unusual.
Caroline Flint, a famous UK midwife and former President of the Royal College of Midwives, has commented that home birth is very safe for first labours precisely because they tend to be slower – it means that there is plenty of time to transfer if there is any sign of trouble.
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8. Birth setting for low-risk pregnancies. An analysis of the current literature.
Albers LL, Katz VL (University of Medicine and Dentistry of New Jersey.)
J Nurse Midwifery 1991 Jul-Aug;36(4):215-20
The authors reviewed literature comparing traditional hospital delivery suites with home birth, free-standing birth centres, and in-hospital birth centres, for women with low-risk pregnancies. They concluded that ‘nontraditional birth settings present advantages for low-risk women as compared with traditional hospital settings: lower costs for maternity care, and lower use of childbirth procedures, without significant differences in perinatal mortality.’
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9. Outcomes of intended home births in nurse-midwifery practice: a prospective descriptive study
Murphy PA; Fullerton J (Department of Obstetrics and Gynecology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA. pam15@columbia.edu)
Obstet Gynecol, 92(3):461-70, September 1998
The pregnancies of 1,404 women planning a home birth with 29 US nurse-midwifery practices were studied in 1994-5. 6% miscarried, terminated the pregnancy or changed plans. 7.4% were referred for planned hospital birth during the pregnancy. Of the remaining 86.6% who still planned home births, 102 (8.3%) were transferred to the hospital during labor. Ten mothers (0.8%) were transferred to the hospital after delivery, and 14 infants (1.1%) were transferred after birth. The proportion of babies in this group which died during labour or shortly after birth was 2.5 per 1000. For women actually delivering at home (those who did not transfer), the rate was 1.8 per 1000. Conclusion: ‘Home birth can be accomplished with good outcomes under the care of qualified practitioners and within a system that facilitates transfer to hospital care when necessary. Intrapartal mortality during intended home birth is concentrated in postdates pregnancies with evidence of meconium passage. ‘
Abstract on Medline
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10. Meta-analysis of the safety of home birth
Olsen O (Department of Social Medicine, University of Copenhagen, Denmark.)
Birth, 24(1):4-13; discussion 14-6 1997 Mar
Olsen looked at six controlled studies covering 24,092 mainly low-risk women planning home or hospital births. Outcomes were compared for mortality, morbidity (injury and illness), Apgar scores, maternal lacerations (perineal and vaginal tears etc.), and intervention rates. Perinatal mortality was not significantly different between the planned home and planned hospital groups, but the planned home birth group had fewer low Apgar scores, and fewer severe maternal lacerations. There was less medical intervention in the planned home birth group: fewer inductions, fewer episiotomies, fewer assisted deliveries, and fewer caesareans. Unfortunately, the abstract does not give transfer rates, but these outcomes do compare planned home births with hospital births. Olsen concluded: ‘Home birth is an acceptable alternative to hospital confinement for selected pregnant women, and leads to reduced medical interventions.’
Abstract on Medline
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11. Outcomes of 11,788 planned home births attended by certified nurse-midwives. A retrospective descriptive study.
Anderson RE, Murphy PA
J Nurse Midwifery 1995 Nov-Dec;40(6):483-92
The outcomes of 11,788 planned home births in the USA, attended by certified nurse-midwives (CNMs) from 1987 to 1991, were recorded. For those planning a home birth when labour started, the intrapartum and neonatal mortality rate (babies dying in labour and shortly after birth) was 2 per 1,000, falling to 0.9 per 1,000 when deaths associated with congenital abnormalities were excluded. Of women planning a home birth, 7.9% were referred to hospital before the start of labour, because of complications in the pregnancy, and a further 8% were transferred to hospital during labour. The authors conclude: ‘This study supports previous research indicating that planned home birth with qualified care providers can be a safe alternative for healthy lower risk women. ‘
Abstract on Medline
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On to Page Four of the Research Summaries
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