Hypertensive Disorders

Hypertensive disorders occur in about 6 to 8% of pregnancies. There are four major hypertensive disorders in pregnancy, each with different clinical features, risk factors, and associated risks:

• Preeclampsia-eclampsia is hypertension with multisystem involvement that begins after 20 weeks gestation in a woman who previously had normal blood pressure. Often the multisystem involvement presents as proteinuria, however preeclampsia may present with new onset of thrombocytopenia (platelet count under 100,000/microliter), impaired liver function, renal insufficiency, pulmonary edemia, or cerebral or visual disturbances. Eclampsia is the progression of preeclampsia to the convulsive stage marked by developing grand mal seizures in a woman with preeclampsia. Not all women with preeclampsia will progress to eclampsia.
• Chronic hypertension is hypertension that predates conception or developed before 20 weeks gestation
  
• Preeclampsia superimposed upon chronic hypertension is the onset of proteinuria (after 20 weeks gestation) in a woman with chronic hypertension. Like in the diagnosis of preeclampsia without chronic hypertension, other organ system involvement may be present without the onset of proteinuria or with earlier onset of proteinuria (before 20 weeks gestation)
• Gestational hypertension is mild hypertension without proteinuria that develops in the latter part of pregnancy. Some women with gestational hypertension will develop preeclampsia during the course of the pregnancy. If hypertension persists postpartum, the diagnosis should be changed to chronic hypertension.
• Postpartum hypertension including preeclampsia with organ system involvement may develop in a period ranging from 2 weeks to 6 months postpartum. Generally, blood pressure will normalize by the end of the first year, however this may be a predictor of future chronic hypertension.
  

Risk factors for hypertenstion include: (ACOG, 2013)

• First pregnancy (excluding miscarriages)
• Overweight
• Diabetes, renal disease, lupus, or diabetes prior to pregnancy
• Multiple gestation
• Family history of hypertension (sister or mother)
• Previous preeclampsia
• Advanced maternal age >40 years
• In vitro fertilization

In most cases preeclampsia does not lead to serious complications, however, severe preeclampsia can lead to stroke, heart failure, or liver or kidney damage. It is also associated with fetal growth restriction, preterm delivery, and miscarriage or stillbirth. This section focuses primarily on preeclampsia. (Norwitz, 2018)