Obstetrics and Gynecology Clinics of North America
CHRONIC HYPERTENSION IN PREGNANCY
Section snippets
PREVALENCE
The prevalence of chronic hypertension in pregnancy varies among populations depending on maternal age and ethnicity. Chronic hypertension is observed in 1% to 5% of pregnant women depending on the diagnostic criteria used.62 In recent reports, the incidence was 2.5% among African-Americans and 1% among other racial groups.80 The prevalence of chronic hypertension also varies according to age. The reported rates range from 1.9% at 20 to 29 years to 5.7% at 30 to 39 years among African-Americans
DEFINITION AND DIAGNOSIS
Chronic hypertension is characterized by an elevated blood pressure occurring before pregnancy, by hypertension occurring during pregnancy before 20 weeks' gestation, or by hypertension persisting beyond 6 weeks' postpartum. Hypertension is defined as a systolic blood pressure of at least 140 mm Hg or a diastolic blood pressure of at least 90 mm Hg on at least two occasions at least 4 hours apart.62 In pregnant women whose prepregnancy blood pressure is unknown, the diagnosis of chronic
ETIOLOGY AND CLASSIFICATION
The etiology of essential hypertension remains elusive. Chronic hypertension is a complex disease in which genetic predisposition interacts with multiple environmental factors. The etiology of chronic hypertension is an important consideration in pregnancy. Chronic hypertension can be subdivided into primary (idiopathic) and secondary. Primary idiopathic hypertension accounts for 90% of chronic hypertension seen during pregnancy. Secondary hypertension (10%) is related to several underlying
MATERNAL RISKS
Abruptio placentae in women with chronic hypertension is increased, with a prevalence of up to 10%.91 In women with mild chronic hypertension, the incidence was nearly 1.5% to 2% and was not influenced by antihypertensive treatment.82, 89 The incidence of abruptio placentae in women with severe hypertension ranged from 2.3%84 to 9.5%.82 Sibai and co-workers reported an overall incidence of abruptio placentae of 1.5%. The frequency was significantly higher in women with superimposed preeclampsia
PERINATAL RISKS
The risk of perinatal death is increased two to four times in women with chronic hypertension when compared with the general population.1, 38, 73 In a follow-up study of 337 pregnancies among 298 women with chronic hypertension, the rate of perinatal mortality was 45 in 1000 compared with a rate of 12 in 1000 in the general population (P <0.001).73 Rates for premature deliveries and small-for-gestational age (SGA) infants were also found to be higher in women with chronic hypertension.1, 31, 38
MANAGEMENT
The goal in managing chronic hypertension is to reduce pregnancy-related complications and maternal cerebral hemorrhage. Care for women with chronic hypertension should begin before conception. Drugs that may have adverse side effects on the fetus [e.g., angiotensin-converting enzyme inhibitors (ACE)] should be discussed and discontinued if necessary. Based on the medical history and clinical and laboratory findings, pregnant women with chronic hypertension can be divided into low- or high-risk
LOW-RISK CHRONIC HYPERTENSION
Pregnant women with chronic hypertension are considered to be at low risk in cases of mild hypertension without any organ involvement. The maternal benefits of pharmacologic treatment of mild chronic hypertension are not clear, and whether antihypertensive treatment improves perinatal outcome remains controversial. Few prospective randomized studies have been conducted to determine whether antihypertensive treatments in these women improve maternal or perinatal outcome.4, 14, 30, 34, 35, 44, 68
HIGH-RISK CHRONIC HYPERTENSION
Women with chronic hypertension who are considered high risk have severe hypertension or mild hypertension associated with signs of end-organ involvement, concomitant disease, or a poor obstetric history. This group of patients is at high risk for pregnancy complications, including superimposed preeclampsia, abruptio placentae, SGA infants, and prematurity.55, 73, 84, 88 Patients with renal insufficiency, diabetes (all classes), collagen vascular disease, cardiomyopathy, or coarctation of the
PHARMACOLOGIC TREATMENT
The initiation of pharmacologic treatment of chronic hypertension in pregnant women must take into account the severity of hypertension and the risk of target organ damage. For women with high-risk hypertension, the authors recommend treatment at a diastolic blood pressure of 90 mm Hg or higher. Other clinicians recommend treatment when the diastolic blood pressure is 100 mm Hg or higher in high-risk patients.62 In women with low-risk hypertensive pregnancy, the authors recommend
MEDICATION TO PREVENT SUPERIMPOSED PREECLAMPSIA
Initial reports studying the prophylactic use of low-dose aspirin, ranging from 50 to 150 mg daily, included a limited number of patients.9, 98 Recently, Caritis and co-workers16 studied the effect of low-dose aspirin (60 mg/day) for the prevention of preeclampsia. In this prospective, randomized, double-blind, placebo-controlled trial that included 2539 pregnant women at high risk for the development of preeclampsia, 774 had chronic hypertension. The women were enrolled between gestational
POSTPARTUM MANAGEMENT
Women with high-risk chronic hypertension are at risk for postpartum complications, such as pulmonary edema, hypertensive encephalopathy, or renal failure.91 These risks are particularly increased in women having a target organ involvement, superimposed preeclampsia, abruptio placentae, morbid obesity, or long-standing hypertension. In these women, blood pressure must be closely controlled for at least 48 hours after delivery. Intravenous labetalol or hydralazine can be used as needed51 in
SUMMARY
Pregnant women with chronic hypertension are at risk for maternal and perinatal morbidity. Careful assessment and management of these patients during pregnancy are the keys to reducing maternal and fetal complications. Antihypertensive treatment should be used in women with high-risk chronic hypertension, whereas drug therapy does not improve pregnancy outcome in women at low risk. Prophylactic low-dose aspirin started early in pregnancy in women with chronic hypertension is not effective in
References (105)
- et al.
Concentrations of beta-blocking drugs in human milk
J Pediatr
(1990) - et al.
Prevention of pre-eclampsia by early antiplatelet therapy
Lancet
(1985) - et al.
Blood pressure patterns in normal pregnancy and in pregnancy-induced hypertension, preeclampsia, and chronic hypertension
Obstet Gynecol
(1996) - et al.
Predictors of pre-eclampsia in women at high risk
Am J Obstet Gynecol
(1998) - et al.
Effect of antioxidants on the occurrence of pre-eclampsia in patients at increased risk: A randomized trial
Lancet
(1999) - et al.
Pregnancy in the patient with hypertensive disease
Am J Obstet Gynecol
(1947) - et al.
Final report of study on hypertension during pregnancy: The effects of specific treatment on the growth and development of the children
Lancet
(1982) - et al.
Oligohydramnios sequence and renal tubular malformation associated with maternal enalapril use
Am J Obstet Gynecol
(1990) - et al.
Nifedipine transfer into human milk
J Pediatr
(1989) - et al.
A controlled trial of hypotensive agents in hypertension in pregnancy
Lancet
(1968)
Effect of atenolol on birth weight
Am J Cardiol
Atenolol and fetal growth in pregnancies complicated by hypertension
Am J Hypertens
The safety of calcium channel blockers in human pregnancy: A prospective, multicenter cohort study
Am J Obstet Gynecol
The preterm prediction study: Risk factors for indicated preterm births
Am J Obstet Gynecol
Effects of methyldopa on uteroplacental and fetal hemodynamics in pregnancy-induced hypertension
Am J Obstet Gynecol
Hypertension during pregnancy, with-and-without specific hypotensive treatment. II. The growth and development of the infant in the first year of life
Early Hum Dev
Fetal outcome in trial of antihypertensive treatment in pregnancy
Lancet
Controlled trials of antihypertensive drugs in pregnancy
Am J Kidney Dis
The prognosis of pregnancy in women with chronic hypertension
Am J Obstet Gynecol
Obstetric aspects of the use in pregnancy-associated hypertension of the beta-adrenoreceptor antagonist atenolol
Am J Obstet Gynecol
Maternal hypertension and associated pregnancy complications among African-American and other women in the United States
Obstet Gynecol
A protocol for managing severe preeclampsia in the second trimester
Am J Obstet Gynecol
A randomized prospective comparison of nifedipine and bed rest versus bed rest alone in the management of preeclampsia remote from term
Am J Obstet Gynecol
Effects of diuretics on plasma volume in pregnancies with long-term hypertension
Am J Obstet Gynecol
Chronic hypertension in pregnancy
Clin Perinatol
Treatment of hypertension in pregnancy with methyldopa, randomized double-blind study
Int J Gynaecol Obstet
Hypertensive disorders of pregnancy and stillbirth in North Carolina, 1988 to 1991
Acta Obstet Gynecol Scand
From the Centers for Disease Control and Prevention. Postmarketing surveillance for angiotensin-converting enzyme inhibitor use during the first trimester of pregnancy—United States, Canada, and Israel, 1987–1995
JAMA
Postmarketing surveillance for angiotensin-converting enzyme inhibitor use during the first trimester of pregnancy—United States, Canada, and Israel, 1987–1995
MMWR Morb Mortal Wkly Rep
Antihypertensive treatment and pregnancy outcome in patients with mild chronic hypertension
Obstet Gynecol
Chronic hypertension and pregnancy
Angiotensin-converting enzyme inhibitors use in the first trimester of pregnancy
International Journal of Risk and Safety in Medicine
Does advanced maternal age affect pregnancy outcome in women with mild hypertension remote from term?
Am J Obstet Gynecol
Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk
Prevalence of hypertension in the US adult population: Results from the Third National Health and Nutrition Examination Survey, 1988–1991
Hypertension
An overview of the influence of ACE inhibitors on fetal-placental circulation and perinatal development
Mol Cell Biochem
Atenolol in essential hypertension during pregnancy
BMJ
Low-dose aspirin to prevent preeclampsia in women at high risk
N Engl J Med
A randomized trial of low-dose aspirin for the prevention and treatment of pre-eclampsia among 9364 pregnant women
Lancet
Does labetalol influence the development of proteinuria in pregnancy hypertension? A randomised controlled study
Eur J Obstet Gynecol Reprod Biol
[Treatment of hypertension in pregnant women with beta-blockers: 60 cases (authors' translation)]
Presse Med
Randomised controlled comparative study of methyldopa and oxprenolol in the treatment of hypertension in pregnancy
BMJ (Clin Res Ed)
Thiazide and neonatal thrombocytopenia [letter]
N Engl J Med
Antihypertensive treatment in pregnancy: Analysis of different responses to oxprenolol and methyldopa
BMJ (Clin Res Ed)
Randomised comparison of methyldopa and oxprenolol for treatment of hypertension in pregnancy
BMJ
Verapamil prophylaxis in pregnant women with bipolar disorder [letter]
Am J Psychiatry
Nifedipine versus expectant management in mild to moderate hypertension in pregnancy
Br J Obstet Gynaecol
Effect of uncomplicated chronic hypertension on the risk of small-for-gestational age birth
Am J Epidemiol
Fetal and neonatal effects of treatment with angiotensin-converting enzyme inhibitors in pregnancy
Obstet Gynecol
Cited by (25)
New Evidence in the Management of Chronic Hypertension in Pregnancy
2017, Seminars in NephrologyMaternal and fetal morbidity following discontinuation of antihypertensive drugs in mild to moderate chronic hypertension: A 4-year observational study
2016, Pregnancy HypertensionCitation Excerpt :Chronic hypertension complicates between 1% and 5% of pregnancies. It is associated with poor outcomes of pregnancy and, together with hemorrhage, was of the major contributors to maternal morbidity and mortality in developed and developing countries [1–3]. Women with chronic hypertension had high pooled incidences of superimposed pre-eclampsia, cesarean section, preterm delivery, birth weight <2500 g, neonatal unit admission and perinatal death [4,5].
Hypertension and antihypertensive drugs in pregnancy and perinatal outcomes
2013, American Journal of Obstetrics and GynecologyPrevalence, trends, and outcomes of chronic hypertension: A nationwide sample of delivery admissions
2012, American Journal of Obstetrics and GynecologyMaternal asthma, race and low birth weight deliveries
2011, Early Human Development
Address reprint requests to Jeffrey C. Livingston, MD, Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Carilion Roanoke Community Hospital, Prenatal Diagnosis Center, 102 Highland Southeast, Suite 445, Roanoke, VA 24029–2946, e-mail: [email protected]