Friday, July 13, 2012

A stunning indictment of midwives in The Netherlands

Homebirth and midwifery advocates point with pride to a recent study that showed that homebirth with a midwife in the Netherlands is as safe as hospital birth with a midwife (Perinatal mortality and morbidity in a nationwide cohort of 529 688 low-risk planned home and hospital births). They tout this study as evidence that homebirth is as safe as hospital. A new study suggests an entirely different explanation: Dutch midwives have unacceptably high rates of perinatal mortality both at home and in the hospital. Indeed, the perinatal mortality rate for LOW risk women cared for by Dutch midwives is HIGHER than the perinatal mortality rate for HIGH risk women cared for by Dutch obstetricians!

The new study, Perinatal mortality and severe morbidity in low and high risk term pregnancies in the Netherlands: prospective cohort study, appears in this week's issue of the British Medical Journal. The authors explain that the study was undertaken to investigate why the Netherlands has highest perinatal mortality rate in Europe.

Several factors are mentioned as possible explanations for this high mortality, such as differences in registration and maternal characteristics of the Dutch childbearing population, restricted management of premature babies, and the absence of standard screening for congenital anomalies. The numbers of older mothers, multiple pregnancies, and mothers belonging to an ethnic minority are relatively high in the Netherlands. However, this can only partly explain the high perinatal mortality. Whether the Dutch obstetric care system contributes to this relatively high mortality remains unclear.
This is an important question because the Dutch system of maternity care relies primarily on midwives and those midwives perform a relatively high number of homebirths. This study, a cohort study of severe morbidity and mortality of term fetuses or neonates, called ATNICID (Admission of Term Neonates to Intensive Care or Intrauterine Death), was begun in 2007 with the express intent of examining the relationship between the organization of the Dutch maternity care system and the high rate of perinatal mortality.

The study ultimately enrolled 37,735 term infants without congenital anomalies:
16,672 (44.2%) infants of nulliparous women (including 143 (0.9%) twin pregnancies) and 21,063 (55.8%) infants of multiparous women (including 226 (1.1%) twin pregnancies). Data on 91 (0.2%) infants were missing; we excluded these from further analysis... 18,686 (49.5%) infants were born to women who started labour in primary care as low risk, of whom 5492 (29.4%) were referred to secondary care during labour; 13,194 (35.0%) infants were born under the supervision of a midwife in primary care, and 24,450 (64.8%) infants were born under the supervision of a gynaecologist.
The results were astounding:
Of the 60 antepartum stillbirths, 37 occurred in primary care and 23 in secondary care...

Twenty-two intrapartum stillbirths and 14 delivery related neonatal deaths occurred. Infants of pregnant women at low risk had a significantly higher risk of delivery related perinatal death (relative risk 2.33, 1.12 to 4.83), compared with infants of women at high risk whose labour started in secondary care under the supervision of an obstetrician. Infants of women who were referred to secondary care during labour had a 3.66 times higher risk of delivery related perinatal death than did infants of women who started labour in secondary care (relative risk 3.66, 1.58 to 8.46)...
A total of 210 infants were admitted to the NICU:
... resulting in an overall incidence of admission to NICU of 5.58 (4.83 to 6.33) per 1000 live births.... Half of the women (51%, n=107) started labour in primary care. Of these, 70% (n=75) were referred to secondary care during labour... The incidence of admissions to the NICU was 2.43 per 1000 term births in primary care, 13.7 per 1000 term births if referral to secondary care during labour occurred, and 5.45 per 1000 term births managed exclusively in secondary care.
Nearly half the NICU admissions were the result of one cause: asphyxia. Among the 17 infant deaths:
71% (n=12) [were] because of asphyxia and 29% (n=5) because of an infection. Fourteen cases were classified as directly related to circumstances during labour.
Of the 26 deaths related to labor presided over by midwives, 65% were attempted homebirths.

These results are deeply shocking.
We found that delivery related perinatal death was significantly higher among low risk pregnancies in midwife supervised primary care than among high risk pregnancies in obstetrician supervised secondary care. This difference was even greater among the cases that were referred from primary to secondary care during labour. Unfortunately, we were unable to adjust for confounding variables because we used aggregated data from a large birth registry database. However, the results are unlikely to have been overestimated, because risk factors such as low socioeconomic status, higher age, or non-Western ethnicity were more prevalent among the women at high risk. (my emphasis)
The authors express their concern:
In summary, the Dutch obstetric care system is based on the assumptions that pregnant women and women in labour can be divided into a low risk group and a high risk group, that the first group of women can be supervised by a midwife (primary care) and the second group by an obstetrician (secondary care), and that women in the primary care group can deliver at home or in hospital with their own midwife. When complications occur or risk factors arise antenatally, during labour, or in the puerperium in primary care, the women is referred to secondary care. We found that the perinatal death rate of normal term infants was higher in the low risk group than in the high risk group, so the Dutch system of risk selection in relation to perinatal death at term is not as effective as was once thought. This also implies that the high perinatal death rate in the Netherlands compared with other European countries may be caused by the obstetric care system itself, among other factors. A critical evaluation of the obstetric care system in the Netherlands is thus urgently needed.
In contrast to the claims of homebirth and midwifery advocates, the Netherlands is far from being the ideal model of obstetric care. The Netherlands has the highest perinatal mortality in Europe, and midwifery care may very well be the cause of this calamity.

This piece first appeared on The Skeptical OB in November 2010.

No comments:

Post a Comment