A systematic review in 2010[29] studied the role of
biochemical markers associated with ultrasonographic
markers to improve the possibility of prediction for early
preeclampsia. The authors included 37 articles within
their review in which the most frequently studied biochemical
markers were hCG (human chorionic gonadotropin),
inhibin A, a-fetoprotein, sFlt-1 (soluble fms-like
tyrosine kinase 1), PAPP-A, activin A, placental growth
factor (PlGF) and PP-13. In some cases, markers were
evaluated in the second trimester as well as the ultrasound
velocimetry, in other cases the markers were assessed
during the first trimester before ultrasonographic evaluation.
The analysis of these papers elucidates that the addition
of biochemical markers to uterine artery Doppler
ultrasound scan in the second trimester or the combination
of first trimester biochemical and second trimester
uterine velocimetry improves the predictive performance
of ultrasound alone and of markers alone. This review
also suggests that the addition of maternal characteristics
does improve their predictive power.
Despite these promising results, the heterogeneity
between studies regarding gestational age at the study
time or the selected populations (high vs low risk) led to
uncertainty about the combination of ultrasonographic
and biochemical markers as a screening procedure for
preeclampsia.
Maternal echocardiography: It is well known that important
changes occur in pregnancy in the hemodynamic
and cardiovascular system, with initial vasodilatation