Reproductive · Hypertensive Disorders of Pregnancy
The facts most likely to be tested
Gestational hypertension is defined as a systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg on two occasions at least four hours apart after 20 weeks of gestation in a previously normotensive woman.
The diagnosis of gestational hypertension requires the absence of proteinuria and the absence of new-onset end-organ dysfunction to exclude preeclampsia.
First-line antihypertensive therapy for severe hypertension (≥160/110 mmHg) in pregnancy includes labetalol, nifedipine, or hydralazine.
Delivery is recommended at 37 weeks 0 days of gestation for patients with gestational hypertension to reduce the risk of progression to preeclampsia.
Patients with gestational hypertension require serial blood pressure monitoring and fetal growth assessment via ultrasound to monitor for intrauterine growth restriction (IUGR).
Gestational hypertension is a diagnosis of exclusion that is confirmed only postpartum when blood pressure levels return to normal within 12 weeks.
The presence of severe range blood pressures, thrombocytopenia, impaired liver function, renal insufficiency, pulmonary edema, or cerebral/visual disturbances mandates a diagnosis of preeclampsia with severe features rather than gestational hypertension.
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A 28-year-old G1P0 woman at 34 weeks gestation presents for a routine prenatal visit. She reports no headaches, visual changes, or abdominal pain. Her blood pressure is 145/92 mmHg and 148/94 mmHg on two separate readings taken four hours apart. A urine dipstick shows negative protein, and laboratory studies reveal normal platelet count, normal liver enzymes, and normal serum creatinine. She has no history of chronic hypertension.
What is the most appropriate diagnosis?
Gestational hypertension
The patient meets the criteria for gestational hypertension because she has new-onset hypertension after 20 weeks gestation without proteinuria or signs of end-organ damage, as defined in the first and second bets.
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Etiology / Epidemiology
New-onset hypertension after 20 weeks gestation in a previously normotensive patient without proteinuria or end-organ damage.
Clinical Manifestations
Often asymptomatic; identified via routine prenatal screening. Monitor for preeclampsia progression: headache, visual changes, epigastric pain.
Diagnosis
Systolic ≥140 mmHg or diastolic ≥90 mmHg on two occasions at least 4 hours apart.
Treatment
Delivery at 37 0/7 weeks. First-line antihypertensives: Labetalol or Nifedipine.
Prognosis
Risk of progression to preeclampsia; postpartum blood pressure usually normalizes by 12 weeks.
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Epidemiology & Etiology
Occurs in ~6-10% of pregnancies. Primary risk factors include nulliparity, multifetal gestation, advanced maternal age, and history of chronic hypertension.
Pertinent Anatomy
The placenta is the central organ of pathology, where abnormal spiral artery remodeling leads to systemic vascular resistance.
Pathophysiology
Inadequate trophoblast invasion results in placental ischemia and the release of anti-angiogenic factors into maternal circulation. This triggers widespread endothelial dysfunction, leading to vasoconstriction and increased systemic vascular resistance.
Clinical Manifestations
Patients are typically asymptomatic. Red flags indicating progression to preeclampsia include severe headache, scotomata, epigastric/RUQ pain, and pulmonary edema. Monitor for seizures (eclampsia) and HELLP syndrome.
Diagnosis
Diagnosis requires two readings ≥140/90 mmHg at least 4 hours apart. Must rule out proteinuria or end-organ dysfunction to distinguish from preeclampsia. 24-hour urine protein or protein/creatinine ratio is used to exclude proteinuria.
Treatment
Initiate antihypertensives if BP is ≥160/110 mmHg. Labetalol or Nifedipine are first-line. ACE inhibitors and ARBs are strictly contraindicated due to fetal renal failure. Delivery is recommended at 37 0/7 weeks.
Prognosis
Patients require weekly monitoring for progression to preeclampsia. Postpartum, BP must be reassessed at 12 weeks; persistent hypertension suggests chronic hypertension.
Differential Diagnosis
Chronic Hypertension: BP elevation present before 20 weeks gestation
Preeclampsia: Gestational HTN plus proteinuria or end-organ damage
Gestational Proteinuria: Proteinuria without hypertension
HELLP Syndrome: Hemolysis, Elevated Liver enzymes, Low Platelets
Eclampsia: New-onset generalized tonic-clonic seizures