PREDISPOSING FACTORS : - INCREASED AGE, BLACK RACE, MULTIPLE GESTATIONS, CONCOMITANT RENAL OR CARDIAC DISEASE & CHRONIC HYPERTENSION
RISK FACTORS
β’ Familial incidence
β’ Lower socioeconomic
β’ Multiple fetuses
β’ Teenage
β’ Collagen disorders
β’ Females > 35 years old
β’ Primigravida
β’ First subsequent pregnancy with a different father
β’ Diabetes mellitus of pregnancy
β’ Chronic hypertension
β’ Hydatid mole
β’ Fetal hydrops
β’ History of renal disease
Preeclampsia, a disorder associated with pregnancy that consists of hypertension and proteinuria. The hypertension component of the disease is present when the systolic blood pressure is greater than 140 mm Hg or the diastolic blood pressure is greater than 90 mm Hg in a woman known to be normotensive prior to pregnancy.
Proteinuria is present when the urinary protein concentration is greater than 300 mg during a 24-hour period. The 24-hour urine collection is the definitive test to diagnose proteinuria; however, if it is not available, then a concentration of at least 30 mg/dL (at least 1+ on dipstick testing) in at least 2 random urine samples collected at least 6 hours apart may be used.
MEDICAL TREATMENT :
The only definitive treatment for preeclampsia is delivery of the fetus and placenta. This is a reasonable choice for viable fetuses or in cases in which the mother's health is at significant risk. Examples of significant health risk include eclampsia, pulmonary edema, compromised renal function, abruptio placentae, platelet count less than 100,000/mL, a ratio of serum alanine aminotransferase to serum aspartate aminotransferase that is twice the reference range with concomitant epigastric and right upper quadrant tenderness, persistent severe headache or visual changes, and uncontrolled severe hypertension. In these cases, glucocorticoids can be administered to women with preterm pregnancies, with delivery postponed for 48 hours to allow the steroids to improve fetal lung maturity.
However, preeclampsia often can be treated in women with preterm pregnancies if symptoms are mild to moderate. Examples of this type of preeclampsia include proteinuria of any amount, oliguria (<0.5 mL/kg/h) that resolves with fluid intake, an alanine aminotransferase/aspartate aminotransferase ratio higher than twice the reference range, no abdominal tenderness, and controlled hypertension. In patients with controlled hypertension, the treatment is to lower blood pressure.
Medical management focuses on antihypertensive treatment and anticonvulsant prophylaxis.
In summary, a patient with severe preeclampsia must be admitted to the hospital. The disposition of the preterm patient with mild preeclampsia is less certain. These patients have traditionally been admitted and placed on bed rest for the duration of the pregnancy. Recent studies have suggested that most of these patients can be safely treated at home or in a day-care facility as long as frequent maternal and fetal evaluation can be performed.
Surgical Care: Failure of medical management necessitates iatrogenic vaginal delivery. Maternal or fetal deterioration requires emergent cesarean delivery.
DRUG THERAPY : Drug therapy focuses on treatment of hypertension and prophylaxis against seizures.
Hydralazine is the antihypertensive agent most often used in pregnancy. Some recent studies have suggested that intravenous labetalol or oral nifedipine may be as effective and have fewer adverse effects than intravenous hydralazine. Notably, ACE inhibitors are contraindicated in pregnancy because of their harmful effects on the fetus.
Seizures remain a great concern for any patient with preeclampsia. Magnesium sulfate is the first-line therapy for seizures because it prevents vascular spasm. The prevention of vasospasm in the brain is believed to protect against seizures. Recent studies have shown that magnesium sulfate is effective in reducing seizures in women with eclampsia and severe preeclampsia without affecting overall maternal and perinatal mortality and morbidity. Magnesium sulfate is routinely used in patients with eclampsia and severe preeclampsia. Its use in patients with mild preeclampsia is more controversial, and, in current practice, whether magnesium sulfate is routinely indicated in this group of patients is unclear.
DRUG TREATMENT :
1. ANTIHYPERTENSIVES :
- HYDRALAZINE : Traditionally been the DOC for blood pressure control in preeclampsia. However, labetalol has recently been reviewed and is a reasonable alternative. Labetalol has alpha- and beta-adrenergic blocking effects and can be used to rapidly control severe hypertension. First-line therapy against preeclamptic hypertension. Decreases systemic resistance through direct vasodilatation of arterioles, resulting in reflex tachycardia. Reflex tachycardia and resultant increased cardiac output helps reverse uteroplacental insufficiency, a key concern when treating hypertension in a patient with preeclampsia. Adverse fetal effects are uncommon.
- LABETALOL - Second-line therapy that produces vasodilatation and decrease in systemic vascular resistance. Has alpha1- and beta-antagonist effects and beta2-agonist effects. Has more rapid onset than hydralazine and less overshoot hypotension. Dosage and duration of labetalol are more variable. Adverse fetal effects are uncommon.
- NITROPRUSSIDE : Used when hydralazine and labetalol are ineffective. Reduces peripheral resistance by acting directly on arteriolar and venous smooth muscle. Nitroprusside has very short half-life and therefore allows titration to effect.
2. ANTICONVULSANTS :
- MAGNESIUM SULPHATE : First-line therapy for seizure prophylaxis. Antagonizes calcium channels of smooth muscle. Indicated for severe preeclampsia, eclampsia, and preeclampsia near term. Administer IV/IM for seizure prophylaxis in preeclampsia. Use IV for quicker onset of action in true eclampsia.
- PHENYTOIN
- DIAZEPAM
ALTERNATIVE DRUGS
. Hypertension:
. Hydralazine (Apresoline) 5-10 mg IV q 20-30 minutes,
or
. Diazoxide 30 mg minidose if refractory to hydralazine
. Avoid nitroprusside (decreased uterine blood flow plus possible lethal fetal cyanide levels)
. Seizures:
. MgSO4 - not as effective for treatment of seizures as it is for prophylaxis
. Diazepam (Valium) 10 mg IV followed by 10 mg IM q4h if MgSO4 unavailable or ineffective
PATIENT MONITORING
β’ Keep urine output > 25 cc/hr
β’ Continue MgSO4 for 24 hr postpartum
β’ Give oxytocin (Pitocin) postpartum to prevent bleeding (60 unit/L at 50 cc/hr)
PREVENTION/AVOIDANCE
β’ Weight control
β’ Large scale studies do not support low dose aspirin for prevention
β’ High dose calcium (1gm/day) has not been shown to prevent preeclampsia in low risk women
POSSIBLE COMPLICATIONS
β’ Eclampsia (seizures) - 0-2%
β’ Hypertensive crisis
β’ Acute pyelonephritis
β’ Acute fatty liver
β’ Acute pulmonary edema
β’ HELLP syndrome (5-10%)
EXPECTED COURSE/PROGNOSIS
β’ Prevention of seizures
β’ Delivery of viable fetus
β’ Estimated 30-300 deaths/1000 births depending on neonatal support capabilities