A simple clinical classification system for hypertensive disorders of pregnancy is listed in TABLE 2.
TABLE 2
Classification
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Proteinuria
Proteinuria is usually detected by urine dipstick or the sulfosalicylic acid cold test in random urine samples. The concentration of protein in random samples is highly variable and influenced by several factors, particularly vaginal secretions, urinary tract infection, and activity. Several clinical studies define abnormal proteinuria as at least 1+ on dipstick on 2 occasions 6 or more hours apart.1,2
A common theme in medicolegal claims is the assumption by health-care providers that proteinuria resulted from sample contamination or urinary tract infection. To avoid this problem, dipstick proteinuria should be confirmed by catheterized urine sample, urine culture, or—if necessary—by 12- to 24-hour urine collection.
An abnormal proteinuria of 2+ on dipstick or more than 300 mg per 24-hour collection in association with hypertension establishes the diagnosis of preeclampsia. The physician should document this finding and explain to the patient that it increases the likelihood of convulsions, abruptio placentae, fetal growth retardation, and preterm delivery. The risks for these complications will depend on gestational age at onset, as well as the severity of the abnormalities.
Identifying women at risk
All pregnant women are at risk for hypertension and preeclampsia in the antepartum, intrapartum, and postpartum periods. Therefore, the clinician should measure BP, urine protein, and weight at each prenatal visit. He or she also should measure BP and urine protein during any visits to triage or the emergency room. In addition, BP should be monitored during labor and postpartum. Among the risk factors for preeclampsia are nulliparity, obesity, chronic hypertension, and multifetal gestation (TABLE 3). These risk factors also should be used to identify women at risk for severe hypertension or preeclampsia in the early or late postpartum period. Just as important is educating and instructing women to report the symptoms of preeclampsia in the antepartum and postpartum periods.
TABLE 3
Risk factors for preeclampsia
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Antepartum management
The ultimate goals of therapy for these disorders must always be safety of the mother first and then delivery of a live, mature infant who requires no intensive and prolonged neonatal care.5 The choice between outpatient management or hospitalization and expectant management or consideration for delivery usually depends on 1 or more of several factors (TABLE 4). Thus, it is important to document these findings and discuss management options with the patient.
Mild gestational hypertension. In clinical practice, most women with hypertensive disorders have mild gestational hypertension, and pregnancy outcomes are usually good. However, about 25% of these patients may progress to preeclampsia and be at slightly increased risk for fetal growth retardation (5% to 10%), abruptio placentae (0.06% to 0.08%), HELLP syndrome (1%), and eclampsia (0.1%).6 Thus, those who have a Bishop cervical score of more than 5 at or near term should undergo induction of labor for delivery. Even if conditions for induction are unfavorable, the pregnancy should not continue past 40 weeks’ gestation. Cervical ripening and induction of labor should be performed.5
For patients remote from term (i.e., less than 37 weeks’ gestation), management should include restricted activity at home, close observation of maternal BP and urine protein, weekly checks of platelet count and liver enzymes, and evaluation of fetal status with ultrasonography and nonstress testing. Ultrasound assessment of fetal growth should be performed at the time of diagnosis and repeated every 3 weeks. Nonstress testing should be performed at the same time and repeated if there is a change in maternal condition or evidence of abnormal fetal growth. In addition, as mentioned, the patient should be instructed to remain alert for symptoms of preeclampsia.
The frequency of subsequent office visits, as well as the need for fetal testing, will depend on initial clinical findings and the ensuing progression. If the maternal condition remains stable (i.e., no excessive weight gain, proteinuria, or significant change in blood pressure; appropriate fundal height growth; and a stable fetal kick count), weekly visits are appropriate. Onset of maternal symptoms, a sudden increase in BP, or development of proteinuria requires more frequent evaluation, preferably in the hospital.1,2