Inequalities in maternal health: national cohort study of ethnic variation in severe maternal morbidities

Marian Knight et al (1) report a higher rate of severe maternal
morbidity among non-white versus white women in the U.K. without being
able to explain it by the characteristics of the studied populations.
However, the studied characteristics, e.g. the parity, maternal age, body
mass index are largely insufficient to explain the higher morbidity of the
non-white women in relation to the peripartum hysterectomy, eclampsia and
embolism. Indeed, gestational pathologies such as diabetes or arterial
hypertension implied in the preeclampsia were not identified in each
population and were not compared. The percentage of previous caesarean
section, placenta praevia or accreta which are strongly associated with
postpartum haemorrhage and peripartum hysterectomy (2) in non-white and
white women is not precised. The weight of foetuses and their number (in
case of twins, etc.) is not known in the studied populations. Foetal
macrosomia and multiple pregnancies are also to be taken into account as
an origin of severe maternal morbidity (haemorrhages, embolisms). The
follow-up of the pregnancies was not compared between the two populations
(white and non-white women). The samples’ sizes of white women (505)
versus African black women (17), or Caribbean (46) are too different to be
comparable. Consequently, this study does not inform about the origin of
higher maternal morbidity in non-white women because the risk factors and
the maternal-foetal pathologies related to the studied morbidities were
neither identified nor compared.

References

1. Knight M, Kurinczuk JJ, Spark P, Brocklehurst P; UKOSS.
Inequalities in maternal health: national cohort study of ethnic variation
in severe maternal morbidities. BMJ. 2009 3;338:b542.

2. Glaze S, Ekwalanga P, Roberts G, Lange I, Birch C, Rosengarten A,
Jarrell J, Ross S. Peripartum hysterectomy: 1999 to 2006. Obstet Gynecol.
2008;111:732-8

Competing interests:
None declared