Report of the Canadian Hypertension Society Consensus Conference: 1. Definitions, evaluation and classification of hypertensive disorders in pregnancy

• Published in: Canadian Medical Association journal 1997-09, Vol.157 (6), p.715-725
• Main Authors: Helewa, M. E, Burrows, R. F, Smith, J, Williams, K, Brain, P, Rabkin, S. W
• Format: Article
• Language: English
• Subjects: Blood pressure; Blood Pressure Determination; Canada; Consensus Development Conferences as Topic; Female; Humans; Hypertension - classification; Hypertension - diagnosis; Pregnancy; Pregnancy Complications, Cardiovascular - classification; Pregnancy Complications, Cardiovascular - diagnosis; Review
• ISSN: 0008-4409; 0820-3946; 1488-2329

To provide Canadian physicians with a standard definition of hypertension in pregnancy, recommendations for laboratory investigations and tests for the assessment and management of hypertensive disorders in pregnancy, and a classification of such disorders. To improve or not improve Canadian uniformity and standardization in the investigation and classification of hypertensive disorders in pregnancy. 1) Accuracy, reliability and practicality of diagnostic clinical criteria for hypertensive disorders in pregnancy. 2) Laboratory tests useful to determine severity and prognosis of disorders as measured by maternal and neonatal adverse outcomes. 3) A classification of disorders for use by Canadian physicians to facilitate uniformity and diffusion of research through a common language. Articles on hypertensive disorders in pregnancy published from 1966 to 1996, retrieved through MEDLINE search, related to definitions, tests, diagnostic criteria and classification, as well as documents on diagnosis and classification from authorities in the United States, Europe and Australia and from special interest groups. High priority was given to the principle of preventing adverse maternal and neonatal outcomes through the provision of diagnostic criteria for severity and prognosis and through dissemination of reliable and pertinent information and research results using a common language. BENEFITS, HARMS AND COST: Higher degree of vigilance in diagnosing hypertensive disorders in pregnancy, allowing for earlier assessment and intervention, and more efficient dissemination of comparative information through common language. No harm or added cost is perceived at this time. (1) A diastolic blood pressure of 90 mm Hg or more should be the criterion for a diagnosis of hypertension in pregnancy and should trigger investigation and management. Except for very high diastolic readings (110 mm Hg or more), all diastolic readings of 90 mm Hg or more should be confirmed after 4 hours. (2) A regularly calibrated mercury sphygmomanometer, with an appropriate-sized cuff, is the instrument of choice. A rest period of 10 minutes should be allowed before taking the blood pressure. The woman should be sitting upright and the cuff positioned at the level of the heart. (3) Both Korotkoff phase IV and V sounds should be recorded, but the phase IV sound should be used for initiating clinical investigation and management. (4) A urine protein level of more than 0.3 g/d should be the criterion fo