Early Vascular Adjustments to Prevent Preeclampsia

Healthy pregnancy is accompanied by major hemodynamic changes that benefit the uteroplacental circulation. A first-trimester drop in vascular resistance triggers several compensatory mechanisms, amongst an increase in blood volume and cardiac output, to maintain blood pressure. These adaptations continue and stand until delivery. Women destined to develop gestational hypertensive complications often exhibit deviant hemodynamic adaptation patterns before overt clinical disease. On the one hand, gestational hypertension and late onset preeclampsia are associated with an exaggerated rise in cardiac output on top of a higher prepregnant value, whereas a shallow rise in cardiac output and the lack of a peripheral resistance drop predisposes to the much less common early onset-preeclampsia along with impaired fetal growth. Antihypertensive therapy based on correction of the hemodynamic imbalance between cardiac output and peripheral resistance seems an effective strategy to improve blood pressure control in hypertensive pregnant women. Even more sophisticated, early treatment of altered cardiac output and peripheral resistance adjustments might prevent development of gestational hypertensive complications. One randomized controlled trial treated pregnant women with an augmented cardiac output with a selective beta-blocker, which resulted in a decreased prevalence of preeclampsia from 18% in the placebo group to 4% in the atenolol group (p = 0.04), at a cost of 440gram birth weight. In line of this reasoning, the investigators aimed to evaluate early cardiovascular adjustments during pregnancy in a high-risk population (i.e. women with preeclampsia in their first pregnancy). In this health care traject, women with deviant adaptation to pregnancy were advised tailored medication, i.e. beta-blockade in women with an pronounced high cardiac output profile effectuated by a high heart rate, and a vasodilating agent in women with a high-resistance hemodynamic profile. Women with a mixed hemodynamic profile were advised a centrally acting sympatholytic agent. The investigators aimed to retrospectively compare outcome of women attending this health care project with women who received care as usual in their second pregnancy.