Definition

Preeclampsia: new-onset gestational hypertension with proteinuria or end-organ dysfunction
- Superimposed preeclampsia: preeclampsia that occurs in a patient with chronic hypertension
- HELLP syndrome
  - A life-threatening form of preeclampsia characterized by Hemolysis, Elevated Liver enzymes, and Low Platelets
  - May occur without hypertension or proteinuria
- Occurrence of new-onset hypertension, proteinuria, or end-organ dysfunction at < 20 weeks’ gestation is suggestive of gestational trophoblastic disease.
Eclampsia: new-onset seizures (tonic-clonic, focal, or multifocal) in the absence of other causes ; a convulsive manifestation of hypertensive pregnancy disorders

Epidemiology

Abnormal placental development, specifically inadequate remodeling of spiral arteries, leads to placental ischemia.
This ischemia triggers the release of anti-angiogenic factors (like sFlt-1) and inflammatory cytokines, causing widespread maternal endothelial dysfunction.
The result is systemic vasoconstriction (causing hypertension), increased vascular permeability (leading to proteinuria and edema), and a pro-coagulant state.
Kidney
- Third spacing (ie, intravascular volume depletion) and vasoconstriction of the renal vessels result in decreased urine production (ie, oliguria) and concentrated urine (ie, increased specific gravity) because the kidneys attempt to retain sodium and water.
- Damage to the renal endothelium increases glomerular permeability and allows for leakage of large molecules, as evidenced by proteinuria, which is classic for preeclampsia.
- Renal vasoconstriction causes a decreased glomerular filtration rate (GFR) and an increased serum creatinine level (above baseline). Healthy pregnant patients have decreased baseline serum creatinine levels due to blood volume expansion and increased GFR; therefore, a normal-appearing creatinine level (0.7-0.9 mg/dL) during pregnancy, as seen in this patient, typically indicates renal compromise.

BP Measurement: ≥140/90 on 2 occasions ≥4 hrs apart (or ≥160/110 once confirmed).
Proteinuria Assessment:
- Screen: Urine Dipstick (≥1+).
- Confirm: Urine Protein:Creatinine Ratio (UPCR) ≥0.3 OR 24-hr urine protein >300 mg (Gold Standard).
Key Labs (End-Organ Check):
- CBC: Plt <100k (Thrombocytopenia).
- CMP: Cr >1.1 (or doubling), AST/ALT >2x upper limit normal.
- Smear: Assess for hemolysis (schistocytes) if HELLP suspected.
Fetal Assessment: NST, BPP, Umbilical Artery Doppler (risk of IUGR/oligohydramnios).

Feature	Chronic HTN	Gestational HTN	Preeclampsia	Eclampsia
Onset	< 20 wks	≥ 20 wks	≥ 20 wks	≥ 20 wks
Defining Feature	HTN that predates pregnancy or starts before 20 weeks.	New HTN w/o proteinuria or signs of end-organ damage.	New HTN w/ proteinuria OR signs of end-organ damage (↑Cr, ↑LFTs, low platelets, HA, visual sx).	Preeclampsia + new-onset tonic-clonic seizures.
Management	Monitor; Tx if severe (Labetalol, Nifedipine).	Monitor for progression to preeclampsia.	Delivery is the cure. MgSO4 for seizure prophylaxis in severe cases.	1. MgSO4 (to control seizures) 2. Delivery (once stable).
Key Complication	Superimposed preeclampsia.	Progression to preeclampsia.	HELLP syndrome, eclampsia, placental abruption.	Stroke, status epilepticus, maternal death.
Postpartum	HTN persists.	HTN resolves.	HTN resolves.	HTN resolves.

Prevention: Low-dose Aspirin starting at 12 wks for high-risk pts (e.g., hx of preeclampsia, chronic HTN, multiple gestation).
Delivery Timing (Definitive Tx):
- Gestational HTN / Preeclampsia w/o severe features: Delivery at 37 0/7 wks.
- Preeclampsia w/ severe features: Delivery at 34 0/7 wks (after stabilization).
- HELLP / Eclampsia / Unstable: Immediate delivery regardless of GA (after stabilization).
Acute BP Control (Target <160/105 to prevent stroke):
- IV Hydralazine: Vasodilator. Good for bradycardic pts.
- IV Labetalol: Beta/Alpha blocker. Avoid in asthma/bradycardia.
- PO Nifedipine: Rapid acting. Avoid if vomiting.
Seizure Prophylaxis:
- IV Magnesium Sulfate: Started intrapartum and cont’d 24hrs postpartum.
- Toxicity signs: Loss of DTRs (1st sign) → Resp depression → Cardiac arrest.
- Antidote: Calcium Gluconate.
- Renal Adj: Lower dose in CKD/elevated Cr (Mg excreted by kidneys).
Chronic HTN Management:
- Tx if BP consistently ≥140/90.
- First line: Labetalol, Methyldopa. Second line: Nifedipine.
- Contraindicated: ACEi, ARBs, Direct Renin Inhibitors (teratogenic - renal agenesis).