Interpretation of results and implications for clinical
practice
The observed patterns of racial differences in development of
hypertensive disorders of pregnancy are consistent with those observed
in the development of cardiovascular diseases in non-pregnant
women.39 In a large UK registry of 1,068,318 patients
between 1997 and 2010 from 225 general practices across England, black,
compared to white patients, were more likely to present with ischaemic
stroke and intracerebral haemorrhage while South Asian patients had
significantly higher hazard ratios for angina and myocardial
infarction.40 This study also showed that the median
age of first cardiovascular disease diagnosis was substantially lower in
women of black and South Asian racial origin than white women.
Prediction of PE and GH necessitates first, data obtained from large
prospective observational studies with accurate recording of maternal
demographic characteristics and medical history and the appropriate
infrastructure for obtaining the necessary outcome measures, and second,
multiple logistic regression analysis which defines the independent
contribution of each risk factor. The data from the FMF study fulfil
these criteria and there are several elements from the maternal history
that contribute to PE and GH; in defining the specific contribution of
one risk factor, such as black racial origin, it is essential that all
other factors are taken into account. In the development of the FMF
competing risks model for prediction of PE a wide range of maternal
factors are taken into account to derive the prior risk which is then
adjusted with the addition of biomarkers to obtain the posteriorrisk.41
This systematic review and meta-analysis has highlighted the weakness of
such approach in defining the contribution of one specific risk factor
such as racial origin. Although the combined number of patients arising
from such studies can be very large the heterogeneity between individual
studies and the lack or minimal adjustment for confounders produces
results that cannot be used for accurate prediction of the outcome under
investigation.