This is the current release of the guideline.

This guideline updates a previous version: American College of Obstetricians and Gynecologists (ACOG). Chronic hypertension in pregnancy. Washington (DC): American College of Obstetricians and Gynecologists (ACOG); 2001 Jul. 9 p. (ACOG practice bulletin; no. 29). [52 references]

Chronic hypertension in pregnancy:

• Mild chronic hypertension (systolic blood pressure of 140–159 mm Hg or diastolic blood pressure of 90–109 mm Hg)
• Severe chronic hypertension (systolic blood pressure of 160 mm Hg or greater or diastolic blood pressure of 110 mm Hg or greater)

Pregnant women with chronic hypertension

Diagnosis/Evaluation

1. Initial evaluation before pregnancy or early in pregnancy with specific testing that may include electrocardiography, echocardiography, ophthalmologic examination, and assessment of renal function.
2. Evaluation of fetal growth by ultrasonography

Management/Treatment

1. Antihypertensive medications (labetalol, thiazide diuretics)
2. Counseling regarding effective contraception for women taking angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers

The MEDLINE database, the Cochrane Library, and the American College of Obstetricians and Gynecologists' own internal resources and documents were used to conduct a literature search to locate relevant articles published between January 1985 - August 2011. The search was restricted to articles published in the English language. Priority was given to articles reporting results of original research, although review articles and commentaries also were consulted. Abstracts of research presented at symposia and scientific conferences were not considered adequate for inclusion in this document. Guidelines published by organizations or institutions such as the National Institutes of Health and the American College of Obstetricians and Gynecologists were reviewed, and additional studies were located by reviewing bibliographies of identified articles. When reliable research was not available, expert opinions from obstetrician–gynecologists were used.

Not stated

Studies were reviewed and evaluated for quality according to the method outlined by the U.S. Preventive Services Task Force:

I Evidence obtained from at least one properly designed randomized controlled trial

II-1 Evidence obtained from well-designed controlled trials without randomization

II-2 Evidence obtained from well-designed cohort or case–control analytic studies, preferably from more than one center or research group

II-3 Evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled experiments also could be regarded as this type of evidence.

III Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees

Not stated

Analysis of available evidence was given priority in formulating recommendations. When reliable research was not available, expert opinions from obstetrician-gynecologists were used. See also the "Rating Scheme for the Strength of Recommendations" field regarding Level C recommendations.

Based on the highest level of evidence found in the data, recommendations are provided and graded according to the following categories:

Level A — Recommendations are based on good and consistent scientific evidence.

Level B — Recommendations are based on limited or inconsistent scientific evidence.

Level C — Recommendations are based primarily on consensus and expert opinion.

A formal cost analysis was not performed and published cost analyses were not reviewed.

Practice Bulletins are validated by two internal clinical review panels composed of practicing obstetrician-gynecologists generalists and subspecialists. The final guidelines are also reviewed and approved by the American College of Obstetricians and Gynecologists (ACOG) Executive Board.

The grades of evidence (I-III) and levels of recommendations (A-C) are defined at the end of the "Major Recommendations" field.

The following recommendation is based on good and consistent scientific evidence (Level A):

• Angiotensin-converting enzyme inhibitors (ACE) and angiotensin receptor blockers (ARB) are contraindicated in all trimesters of pregnancy.

The following recommendations and conclusions are based on limited or inconsistent scientific evidence (Level B):

• Women with severe hypertension require antihypertensive medications for acute elevation of blood pressure.
• Based on the overall low rate of adverse effects and good efficacy, labetalol is a good option for first-line treatment of chronic hypertension in pregnancy.
• Atenolol, a pure beta antagonist, was shown to be associated with growth restriction in infants and is not currently recommended for the treatment of chronic hypertension in pregnancy.
• Thiazide diuretic therapy used in women before pregnancy does not need to be discontinued during pregnancy.

The following recommendations are based primarily on consensus and expert opinion (Level C):

• Ideally, a woman with chronic hypertension should be evaluated before conception to ascertain possible end-organ involvement. Specific testing before pregnancy or early in pregnancy might include assessment of renal function, electrocardiography, echocardiography, and ophthalmologic evaluation. The choice of appropriate tests is dependent on the severity of the chronic hypertension.
• Women taking ACE inhibitors or ARBs should receive counseling about the importance of effective contraception, emphasizing that long-acting reversible contraception is most efficacious.
• Evaluation of fetal growth by ultrasonography in women with chronic hypertension is warranted. If growth restriction is suspected, the fetal status should be monitored.

Definitions:

Grades of Evidence

I Evidence obtained from at least one properly designed randomized controlled trial

II-1 Evidence obtained from well-designed controlled trials without randomization

II-2 Evidence obtained from well-designed cohort or case–control analytic studies, preferably from more than one center or research group

II-3 Evidence obtained from multiple time series with or without the intervention. Dramatic results in uncontrolled experiments also could be regarded as this type of evidence.

III Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees

Levels of Recommendation

Level A — Recommendations are based on good and consistent scientific evidence.

Level B — Recommendations are based on limited or inconsistent scientific evidence.

Level C — Recommendations are based primarily on consensus and expert opinion.

None provided

The type of supporting evidence is identified and graded for each recommendation (see the "Major Recommendations" field).

Oral Antihypertensives Used Commonly in Pregnancy

• Labetalol: Headache
• Nifedipine: Headache
• Methyldopa: Maternal sedation, elevated liver function tests (LFTs), depression
• Hydralazine: Use with methyldopa or labetalol to prevent reflex tachycardia; risk of neonatal thrombocytopenia
• Hydrochlorothiazide: Can cause volume depletion and electrolyte disorders

Drugs for Urgent Control of Severe Acute Hypertension in Pregnancy

• Hydralazine: Risk of delayed maternal hypotension, fetal bradycardia
• Labetalol: Probably less risk of tachycardia and arrhythmia than with other vasodilators; increasingly preferred as first-line agent
• Nifedipine: Possible interference with labor

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) are contraindicated during all trimesters of pregnancy.

These guidelines should not be construed as dictating an exclusive course of treatment or procedure. Variations in practice may be warranted based on the needs of the individual patient, resources, and limitations unique to the institution or type of practice.

An implementation strategy was not provided.

Not applicable: The guideline was not adapted from another source.

American College of Obstetricians and Gynecologists (ACOG)

American College of Obstetricians and Gynecologists (ACOG) Committee on Practice Bulletins — Obstetrics

American College of Obstetricians and Gynecologists (ACOG) committees are created or abolished and their overall function defined by the Executive Board. Appointments are made for one year, with the understanding that such appointment may be continued for a total of three years. The majority of committee members are Fellows, but Junior Fellows also are eligible for appointment. Some committees may have representatives from other organizations when this is particularly appropriate to committee activities. The president elect appoints committee members annually.

Not stated

This is the current release of the guideline.

This guideline updates a previous version: American College of Obstetricians and Gynecologists (ACOG). Chronic hypertension in pregnancy. Washington (DC): American College of Obstetricians and Gynecologists (ACOG); 2001 Jul. 9 p. (ACOG practice bulletin; no. 29). [52 references]

Electronic copies: None available

Print copies: Available for purchase from the American College of Obstetricians and Gynecologists (ACOG) Distribution Center, PO Box 4500, Kearneysville, WV 25430-4500; telephone, 800-762-2264, ext. 192; e-mail: sales@acog.org. The ACOG Bookstore is available online at the ACOG Web site .

The following is available:

• Chronic hypertension in pregnancy: Work-up and management. Webcast. Available for a fee from the American College of Obstetricians and Gynecologists (ACOG) Web site .

In addition, proposed performance measures are included in the original guideline document.

The following is available:

• Frequently asked questions: High blood pressure during pregnancy. Atlanta (GA): American College of Obstetricians and Gynecologists (ACOG); 2011 Aug. 2 p. Electronic copies: Available in Portable Document Format (PDF) from the American College of Obstetricians and Gynecologists (ACOG) Web site.

Please note: This patient information is intended to provide health professionals with information to share with their patients to help them better understand their health and their diagnosed disorders. By providing access to this patient information, it is not the intention of NGC to provide specific medical advice for particular patients. Rather we urge patients and their representatives to review this material and then to consult with a licensed health professional for evaluation of treatment options suitable for them as well as for diagnosis and answers to their personal medical questions. This patient information has been derived and prepared from a guideline for health care professionals included on NGC by the authors or publishers of that original guideline. The patient information is not reviewed by NGC to establish whether or not it accurately reflects the original guideline's content.

This NGC summary was completed by ECRI on September 22, 2004. The information was verified by the guideline developer on December 9, 2004. This NGC summary was updated by ECRI Institute on January 23, 2013.

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.