Preeclampsia and Gestational Hypertension

Pregnancy Dating

• Gestational period: normally 38 weeks (9 months) from conception to birth, but calculated from the first day of the last menstrual period (LMP) as 40 weeks (9.5 months or 280 days)
• Trimesters: 1st (12-14 weeks), 2nd (12-14 to 24-28 weeks), 3rd (24-28 to 37-42 weeks)

Pregnancy Terms

• Gravidity (G): number of times a woman has been pregnant (including current pregnancy)
• Parity (P): describes the outcomes of those pregnancies, including term deliveries, preterm deliveries, abortions, and living children
• Example: G4P1112 (4 pregnancies, 1 term delivery, 1 preterm delivery, 1 abortion, and 2 living children)

Preeclampsia

• Definition: BP changes of gestational hypertension and proteinuria (>300 mg/24hrs, >1+ dipstick)
• Severe Preeclampsia: BP >160/110 mmHg, severe proteinuria (>5g/day), edema, and end organ damage (neurological symptoms, renal failure, liver dysfunction, pulmonary edema)
• HELLP syndrome: associated with hypertensive states (10-20% of patients)
• Eclampsia: preeclampsia with seizures, stroke risk 2-3% of patients with severe preeclampsia

Preeclampsia Pathophysiology

• Normal placentation: invasion of cytotrophoblast tissue into maternal spiral arteries, allowing for remodeling of arteries to increase blood flow (occurs by 20 weeks gestation)
• Preeclampsia: cytotrophoblasts fail to fully invade spiral arteries, shallow placental implantation, and narrow vessels, leading to low perfusion and placental hypoxia
• Placenta releases vasoactive substances to alleviate hypoxia, causing vascular damage and other organ damage

Risk Factors

• Genetic risks: personal or family history, immunogenic, more common in first pregnancy or with new partner
• Maternal inflammation, disordered vessel growth, and failure of trophoblasts to express CAMs
• History of vascular diseases (lupus, hypertension, renal disease, diabetes, etc.)

Management

• Only "cure" is delivery and removal of placenta
• Depends on fetal age and maternal condition, balancing act between maternal and fetal health
• Mild/stable presentation: inpatient monitoring, magnesium sulfate for seizure prophylaxis, controlling maternal blood pressure, and providing corticosteroids for fetal lung development
• Severe disease or fetal distress: immediate delivery

Gestational Diabetes

• Maternal insulin resistance is normal in pregnancy, increasing available glucose for the fetus
• GDM occurs when maternal system can't compensate, affecting 10-15% of pregnancies and rising
• GDM increases likelihood of maternal DM and CVD up to 10X

Test your knowledge of preeclampsia, its symptoms, and complications such as gestational hypertension, proteinuria, and HELLP syndrome. Learn how to identify and manage this pregnancy complication.