Thae

SUPPLEMENT Report of the National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy
National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy* Bethesda, Maryland
This report updates the 1990 “National High Blood Pressure Education Program Working Group Report on High Blood Pressure in Pregnancy” and focuses onclassification, pathophysiologic features, and management of the hypertensive disorders of pregnancy. Through a combination of evidence-based medicine and consensus this report updates contemporary approaches to hypertension control during pregnancy by expanding on recommendations made in “The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High BloodPressure.” The recommendations to use Korotkoff phase V for determination of diastolic pressure and to eliminate edema as a criterion for diagnosing preeclampsia are discussed. In addition, the use as a diagnostic criterion of blood pressure increases of 30 mm Hg systolic or 15 mm Hg diastolic with blood pressure 140 mm Hg systolic or >90 mm Hg diastolic in a woman who was normotensive before 20weeks’ gestation. In the absence of proteinuria the disease is highly suspected when increased blood pressure appears accompanied by the following symptoms: headache, blurred vision, and abdominal pain, or by abnormal laboratory test results, specifically low platelet counts and abnormal liver enzyme values. In the past it has been recommended that an incre-

Volume 183, Number 1 Am J ObstetGynecol

Working Group on High Blood Pressure in Pregnancy S3

ment of 30 mm Hg systolic or 15 mm Hg diastolic blood pressure be used as a diagnostic criterion, even when absolute values remain 1.2 mg/dL unless known to be previously elevated). • Platelet count is 27,000 pregnant women, demonstrated minimal to no reduction in the incidence of preeclampsia with low-dose aspirin therapy.89, 135-142An important study on low-dose aspirin prophylaxis among 2539 women at higher risk for preeclampsia was published recently by the National Institutes of Health.89 Included were four subgroups of women with pregestational insulin-treated diabetes mellitus, chronic hypertension, multifetal gestation, or preeclampsia in a previous pregnancy. The incidences of preeclampsia, perinatal death, pretermdelivery, and fetal growth restriction were the same in the aspirinand placebo-treated patients, with no significant differences in outcomes for any of the four subgroups at higher risk. Calcium supplementation. There are no data to indicate that dietary supplementation with calcium will prevent preeclampsia among low-risk women in the United States. Certainly a diet that provides 1000 mg elementalcalcium daily is recommended for general health.143 Whether a diet enriched with calcium beyond this amount may have benefit remains unproven. In a large National Institutes of Health trial with 4589 healthy nulliparous women randomly assigned at 13 to 21 weeks’ gestation to receive 2 g elemental calcium daily or placebo, calcium supplementation neither reduced the incidence or severity ofpreeclampsia nor delayed its onset.144 There were no differences in the prevalence of nonproteinuric hypertension. Even within the subgroup of women with the lowest quintile of dietary calcium intake, similar to that reported for women in many developing countries, no benefit of calcium supplementation was demonstrated.145, 146 Still, randomized trials of calcium supplementation in nulliparous womenconsidered at high risk have demonstrated significant reductions in the incidence of preeclampsia.147-151 Other dietary supplements. Prophylactic magnesium supplementation has not been shown to be beneficial in preventing preeclampsia.152, 153 Three randomized trials of fish oil supplementation for women at high risk for preeclampsia revealed no reduction in the incidence of preeclampsia.154-156 A...