There are four major hypertensive disorders that occur in pregnant women:
●Preeclampsia-eclampsia – Preeclampsia refers to the syndrome of new onset of hypertension and either proteinuria or end-organ dysfunction (table 1) most often after 20 weeks of gestation in a previously normotensive woman . Eclampsia is diagnosed when seizures have occurred.
●Chronic (preexisting) hypertension – Chronic hypertension is defined as systolic pressure ≥140 mmHg and/or diastolic pressure ≥90 mmHg that antedates pregnancy, is present before the 20th week of pregnancy, or persists longer than 12 weeks postpartum.
●Preeclampsia-eclampsia superimposed upon chronic hypertension – Preeclampsia-eclampsia superimposed upon chronic hypertension is diagnosed when a woman with chronic hypertension develops worsening hypertension with new onset proteinuria or other features of preeclampsia (eg, elevated liver enzymes, low platelet count).
●Gestational hypertension – Gestational hypertension refers to elevated blood pressure first detected after 20 weeks of gestation in the absence of proteinuria or other diagnostic features of preeclampsia. Over time, some patients with gestational hypertension will develop proteinuria or end-organ dysfunction characteristic of preeclampsia (table 1) and be considered preeclamptic, while others will be diagnosed with preexisting hypertension because of persistent blood pressure elevation postpartum.