Abbreviations: CRP, C-reactive protein; LDL, low density lipoprotein; PAI-1, plasminogen activator inhibitor-1; TPA Ag, tissue plasminogen activator antigen; VCAM, vascular cell adhesion molecule
by the presence and magnitude of proteinuria; thus, misclassification is possible. It remains uncertain whether preeclampsia and gestational hypertension represent different disease entities or different manifestations of the same disease process; it is possible that insulin resistance may play an
important role in both. The majority of women with preexisting hypertension do well in pregnancy. However, about 20% develop superimposed preeclampsia, with its attendant risks. In both normotensive and essential hypertensive women, blood pressure usually falls in the late first to early second trimester and rises to prepregnancy levels in the third trimester. Thus, blood pressure levels may be normal after the
late first trimester in women with underlying hypertension. Unless blood pressure has been measured before pregnancy or in the early first trimester, underlying essential hypertension may be misdiagnosed as new-onset hypertension in pregnancy. This may pose a substantial problem in research, in that reports of increased cardiovascular risk associated with de novo hypertension in pregnancy may be explained by
failure to recognize the existence of underlying essential hypertension.