SUPERStudy: Hypertension in Pregnancy
Introduction: Hypertension in pregnancy is when a pregnant person’s blood pressure is 140/90 or higher on two separate occasions.
Etiology: Essential hypertension; renovascular hypertension; aortic coarctation; diabetes mellitus; hyperthyroidism; pheochromocytoma; primary hyperaldosteronism; hyperparathyroidism; Cushing’s syndrome; diabetic nephropathy; chronic renal failure; acute renal failure; tubular necrosis; cortical necrosis; pyelonephritis; chronic glomerulonephritis; nephrotic syndrome; polycystic kidney; systemic lupus erythematosus
Epidemiology: Hypertension complicates as many as 10% of all pregnancies. It ranks among the leading causes of maternal morbidity and mortality. Gestational hypertension appears to affect approximately 6% of pregnancies; Chronic hypertension complicates as many as 5% of pregnancies.
Clinical Manifestations
Mild hypertension: Systolic blood pressure ≥ 140 mm Hg or diastolic blood pressure ≥ 90 mm Hg
Severe hypertension: Systolic blood pressure ≥ 160 mm Hg or diastolic blood pressure ≥ 110 mm Hg
Chronic hypertension: Blood pressure ≥ 140 mm Hg systolic or ≥ 90 mm Hg diastolic present on 2 occasions before pregnancy or before 20th week of gestation; Use of antihypertensive medications before pregnancy; Persistence of hypertension beyond 12 weeks postpartum.
Gestational hypertension: A diagnosis of gestational hypertension is made when (1) maternal blood pressure is elevated to ≥ 140 mm Hg systolic or ≥ 90 mm Hg diastolic on 2 occasions 4 hours apart in a previously normotensive woman ≥ 20 weeks’ gestation, and (2) there is no evidence of proteinuria.
-It is distinguished from preeclampsia by the absence of proteinuria or other symptoms
-Approximately ≥ 25% of women diagnosed with gestational hypertension go on to develop preeclampsia.
-Absence of end-organ dysfunction: Proteinuria, increased creatinine, increased liver function tests, pulmonary edema, cerebral or visual symptoms
-Preeclampsia is characterized by the onset of hypertension and proteinuria or other sequelae, usually during the third trimester of pregnancy, but it can occur at or beyond 20 weeks of gestation.
Complications: Severe hypertension increases the mother’s risk of heart attack, cardiac failure, cerebral vascular accidents, and renal failure. The fetus and neonate also are at increased risk from complications such as poor placental insufficiency, fetal growth restriction, preterm birth, placental abruption, stillbirth, and neonatal death.
Diagnosis
The diagnosis of gestational hypertension can only be confirmed after pregnancy if the patient did not go on to develop preeclampsia or chronic hypertension.
Treatment:
Medications
Adrenergic-receptor agents
α-agonist: Methyldopa (FDA pregnancy category B); It has large body of safety data; is a centrally acting alpha-adrenergic agonist that appears to inhibit vasoconstricting impulses from the medullary vasoregulatory center. It is a first-line agent for management of hypertension during pregnancy.
Adverse effects in pregnancy: Sedation, postural hypotension, peripheral edema, anxiety, drowsiness, dry mouth, hemolytic anemia, granulocytopenia, thrombocytopenia
α/β-blocker: Labetalol (FDA pregnancy category C); Labetalol is an alpha 1 receptor blocker as well as a beta-receptor (beta1 and beta2) blocker. It has large body of safety data; It is a first-line agent for management of hypertension during pregnancy. It should be avoided in patients who have asthma, heart disease, or congestive heart failure.
Adverse effects in pregnancy: Fetal bradycardia
β-blockers: propranolol, metoprolol; Avoid with asthma and decompensated heart function
Calcium-channel blocking agents: Nifedipine (FDA pregnancy category C) is a calcium channel blocker that has been used during pregnancy for tocolysis and treatment of hypertension.
Adverse effect in pregnancy: Possible inhibition of labor if used in combination with magnesium sulfate
Vasodilating agent: Hydralazine Hydralazine (FDA pregnancy category C): it causes direct relaxation of arteriolar smooth muscle and decreases blood pressure. It is considered a first-line treatment for hypertension in pregnancy.
Adverse effect in pregnancy: Hypotension, neonatal thrombocytopenia, lupus-like syndrome, tachycardia
Diuretics (furosemide (C ), hydrochlorothiazide (B) are considered a second-line treatment of hypertension in pregnancy. These drugs may best be used in patients with salt-sensitive hypertension or with reduced renal function.
Medications to avoid:Angiotensin-converting enzyme (ACE) inhibitors; Angiotensin receptor blockers (ARBs), atenolol; Use of angiotensin-converting enzyme inhibitors (enalapril, captopril) during pregnancy is associated with fetal hypocalvaria, renal defects, anuria, and fetal and neonatal death. These agents are contraindicated in pregnancy.
Maternal surveillance: Twice-weekly blood pressure measurements; check urine protein, platelets, liver enzymes weekly; close surveillance for signs and symptoms of preeclampsia.
Fetal surveillance with ultrasound for fetal growth every 3 weeks; Daily fetal kick counts; Weekly NSTs and amniotic fluid volume measurement; growth ultrasound monthly; Delivery before 39 weeks
SUPERPoint: Gestational hypertension is new-onset hypertension (≥140/90 mmHg) occurring after 20 weeks of gestation in the absence of proteinuria or systemic findings suggestive of preeclampsia. It is a temporary condition that resolves postpartum and requires close monitoring to prevent progression to preeclampsia or adverse maternal and fetal outcomes.
SUPERFormulas
Pregnant woman + has a blood pressure ≥ 140 mm Hg systolic or ≥ 90 mm Hg diastolic present on 2 occasions before pregnancy or before 20th week of gestation + Use of antihypertensive medications before pregnancy + Persistence of hypertension beyond 12 weeks postpartum = Chronic hypertension in pregnancy
Pregnant woman + previously normotensive + has blood pressure is elevated to ≥ 140 mm Hg systolic or ≥ 90 mm Hg diastolic on 2 occasions 4 hours apart ≥ 20 weeks’ gestation + there is no evidence of proteinuria + patient did not go on to develop preeclampsia or chronic hypertension = Gestational hypertension