Introduction
Hypertensive disorders remain a leading cause of maternal and fetal morbidity and mortality globally. This article consolidates and expands on key diagnostic criteria, classifications, and management strategies based on guidelines from ACOG and Williams Obstetrics, alongside recent clinical advancements.
Classification of Hypertensive Disorders in Pregnancy
Gestational Hypertension
Definition:
New-onset hypertension (systolic ≥140 mmHg or diastolic ≥90 mmHg) occurring after 20 weeks of gestation without accompanying proteinuria or systemic findings of preeclampsia.
Key Features:
Diagnosed based on two separate BP readings at least 4 hours apart.
May progress to preeclampsia, particularly if diagnosed before 32 weeks.
Outcome:
If BP normalizes postpartum without signs of preeclampsia, it remains classified as gestational hypertension.
Preeclampsia ± Severe Features
Definition:
Hypertension after 20 weeks with either proteinuria or systemic involvement (e.g., thrombocytopenia, liver dysfunction, renal impairment, pulmonary edema, or cerebral/visual disturbances).
Severe Features:
BP ≥160/110 mmHg.
Platelet count <100,000/μL.
Serum creatinine >1.1 mg/dL or doubling of baseline.
AST/ALT ≥2× upper limit, or persistent right upper quadrant pain.
Pulmonary edema or new-onset cerebral/visual symptoms.
Management:
Stabilization and delivery if ≥34 weeks.
Severe cases require BP control (labetalol, hydralazine, nifedipine) and seizure prophylaxis (magnesium sulfate).
Eclampsia
Definition:
New-onset generalized tonic-clonic seizures in a patient with preeclampsia, not attributable to other causes.
Management:
Immediate stabilization with magnesium sulfate.
Airway protection and delivery post-stabilization.
Chronic Hypertension
Definition:
Hypertension diagnosed before 20 weeks of gestation or persisting >12 weeks postpartum.
Risks:
Increased likelihood of superimposed preeclampsia, placental abruption, and fetal growth restriction.
Management:
Goal BP: 120–160/80–110 mmHg.
Preferred medications: Labetalol, nifedipine, methyldopa. Avoid ACE inhibitors and ARBs.
Preeclampsia Superimposed on Chronic Hypertension
Definition:
New-onset proteinuria or systemic features of preeclampsia in a patient with preexisting chronic hypertension.
Diagnostic Clues:
Sudden BP escalation or worsening proteinuria.
Systemic features such as thrombocytopenia or liver dysfunction.
Management:
Similar to preeclampsia with heightened maternal-fetal surveillance.
Key Diagnostic Criteria
Hypertension: Systolic ≥140 mmHg or diastolic ≥90 mmHg, confirmed on two readings 4 hours apart.
Severe Hypertension: BP ≥160/110 mmHg.
Proteinuria:
≥300 mg/24-hour urine, or
Protein/Creatinine ratio ≥0.3, or
Dipstick ≥+2 (if no other methods available).
Other Severe Features:
Thrombocytopenia, renal insufficiency, elevated liver enzymes, persistent epigastric pain, pulmonary edema, or neurological symptoms.
Pathophysiology
Abnormal Placentation: Deficient trophoblast invasion results in placental ischemia.
Endothelial Dysfunction: Release of antiangiogenic factors (e.g., sFlt-1) leads to vasoconstriction, capillary leakage, and coagulation abnormalities.
Biomarker Advancements:
sFlt-1/PlGF ratio testing has improved diagnostic precision in uncertain cases (FDA-cleared in 2023).
Management Strategies
Chronic Hypertension:
Initiate antihypertensives if BP ≥160/110 mmHg.
Regular fetal surveillance with non-stress tests and growth ultrasounds.
Gestational Hypertension & Preeclampsia (Without Severe Features):
Admit to rule out severe features.
Expectant management with weekly BP checks and fetal monitoring.
Deliver at 37 weeks if stable.
Preeclampsia with Severe Features:
Hospitalize for close monitoring.
Deliver at ≥34 weeks or earlier if deterioration occurs.
Acute BP control and seizure prophylaxis are critical.
Eclampsia:
Magnesium sulfate for seizure management.
Prompt delivery once stabilized.
HELLP Syndrome:
Immediate delivery recommended if ≥34 weeks or maternal-fetal compromise develops.
Prevention
Low-Dose Aspirin: Initiate 81 mg daily between 12–16 weeks for high-risk women.
Calcium Supplementation: Recommended for populations with low calcium intake.
Postpartum Considerations
Monitor for persistent hypertension or postpartum preeclampsia.
Continue magnesium sulfate for 24 hours postpartum in severe cases.
Reassess BP at 1–2 weeks postpartum. Persistent hypertension beyond 12 weeks confirms chronic hypertension.
Long-Term Implications
History of hypertensive disorders increases cardiovascular risk. Promote lifestyle modifications and long-term follow-up for optimal health outcomes.
Conclusion
The management of hypertensive disorders in pregnancy is multifaceted, requiring timely diagnosis, careful classification, and appropriate interventions. Advances such as sFlt-1/PlGF testing and low-dose aspirin prophylaxis underscore the importance of integrating evidence-based practices to improve maternal-fetal outcomes.
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