Preeclampsia

Understanding the Pathophysiology of Preeclampsia

At the core of preeclampsia is abnormal trophoblastic invasion of the maternal spiral arteries during early placentation. In a normal pregnancy, these vessels widen to handle increased blood flow. In preeclampsia, they remain narrow and high-resistance, leading to decreased placental perfusion and chronic ischemia.

This struggling placenta releases inflammatory factors and proteins into the maternal circulation, causing widespread endothelial dysfunction. The lining of the blood vessels becomes damaged, leading to vasospasm, increased capillary permeability, and activation of the coagulation system. This explains why preeclampsia is a multi-organ condition affecting the kidneys, liver, brain, and clotting system, rather than just a simple elevation in blood pressure.

Clinical Features: How the Patient Presents

Recognizing preeclampsia requires looking beyond standard blood pressure checks. The clinical picture unfolds through a combination of hypertension and end-organ involvement.

• Blood Pressure: New-onset hypertension diagnosed as 140/90 mmHg or higher on two occasions at least four hours apart after 20 weeks of gestation.
• Proteinuria: The presence of 300 mg or more of protein in a 24-hour urine collection, or a protein-to-creatinine ratio of 0.3 or higher.
• Neurological Signs: Persistent frontal headaches, blurred vision, scotomates (blind spots), and hyperreflexia due to cerebral edema and irritability.
• Hepatic Symptoms: Right upper quadrant or epigastric abdominal pain, stemming from liver stretching and microvascular ischemia.
• Fluid Retention: Sudden, generalized edema involving the face, hands, and feet, which goes beyond the normal dependent swelling of a healthy pregnancy.

Distinguishing Mild from Severe Preeclampsia

Midwives must quickly categorize preeclampsia to guide urgent interventions. The presence of specific severe features changes the care plan from outpatient monitoring or induction near term to immediate stabilization and delivery.

Notice that severe features can exist even if blood pressure is only moderately elevated, provided other end-organs like the liver, kidneys, or brain show distress.

Immediate and Long-Term Management Strategies

Definitive treatment for preeclampsia is delivery of the fetus and placenta. However, timing depends on gestational age and maternal stability. For pregnancies under 37 weeks without severe features, expectant management involves strict inpatient or outpatient surveillance.

When severe features appear, the priority shifts to stabilization:

• Antihypertensive Therapy: Administering drugs like hydralazine or labetalol to lower dangerously high blood pressure and prevent stroke.
• Seizure Prophylaxis: Giving intravenous or intramuscular magnesium sulfate to prevent eclamptic seizures.
• Fluid Management: Careful monitoring of intake and output to prevent pulmonary edema, a major risk during and after delivery.

Long-term management requires postpartum follow-up, as blood pressure can remain elevated or spike up to six weeks after birth. Women who experience preeclampsia also carry an increased lifetime risk of cardiovascular disease.

Nursing Care and Maternal-Fetal Monitoring

Midwives and nurses play a front-line role in safeguarding mothers and babies affected by hypertensive disorders. Continuous vigilance can mean the difference between a stable recovery and a life-threatening emergency.

1. Vital Sign Tracking: Monitor blood pressure, pulse, and respiratory rate every 15 to 30 minutes during acute stabilization.
2. Urine Output Measurement: Use an indwelling urinary catheter to track hourly urine volume, ensuring output remains above 30 mL per hour.
3. Fetal Surveillance: Perform continuous electronic fetal monitoring to check for baseline changes or decelerations caused by reduced placental blood flow.
4. Magnesium Watch: Regularly assess deep tendon reflexes, respiratory rate, and urine output while the patient receives magnesium sulfate to catch early signs of toxicity.