A survey of canadian practitioners regarding diagnosis and evaluation of the hypertensive disorders of pregnancy

Abstract

Background: How Canadian practitioners are diagnosing and managing the hypertensive disorders of pregnancy (HDP), particularly in relation to the 1997 recommendations published by the Canadian Hypertension Society (CHS), is not known.

Methods: A survey, with French and English versions (and covering diagnosis, evaluation, and management of pregnancy hypertension), was mailed to all members of the Society of Obstetricians and Gynaecologists of Canada (SOGC) (N = 1757, including obstetricians, family doctors practicing obstetrics, and midwives). Additionally, internists [i.e., all nephrologists (N = 191) and a random sample of 25% of general internists (N = 450)] registered with the Royal College of Physicians and Surgeons of Canada were sampled. The survey was distributed in two mailings and one reminder card. Data were entered into Microsoft Access, and Graph Pad Prism used to summarize responses [N (%)]. Differences in practice between specialties were examined, with a Bonferonni correction used to calculate a significant p value based on the number of comparisons and alpha of 0.05.

Results: Respondents numbered 1187 (49.5%), with 466 not informative for the purpose of the study (due to retirement, or practices that do not include pregnant women with hypertension). The final analysis included 721 completed surveys. Most (609, 84.5% of) respondents take blood pressure (BP) with women in the sitting position, and use a mercury sphygmomanometer (79%) and the 5th Korotkoff (61%) sound to designate diastolic BP (dBP). To monitor pregnancies complicated by preeclampsia, most clinicians use the proposed laboratory tests of maternal well-being (usually at least once/week), fetal well-being [nonstress test (NST, at least once/week), and ultrasonographic studies (once weekly to every two weeks)]. There is general agreement that women with preeclampsia should be delivered for uncontrolled hypertension, end-organ dysfunction, or fetal compromise (nonreassuring NST, severe oligohydramnios, biophysical profile < 4, estimated fetal weight < 5th centile, and reversed end-diastolic flow by umbilical artery Doppler velocimetry). Less consensus was seen for delivery for preeclampsia at > 34 weeks, mild asymptomatic HELLP syndrome, hyperreflexia, and absent end-diastolic flow by umbilical artery Doppler velocimetry.

Interpretation: This survey has clarified the current state of practice with respect to the diagnosis and evaluation of women with all types of HDP. In particular, we have identified areas of potential variability in BP measurement, and provided data on the feasibility of enrolling women with sub types of preeclampsia into intervention studies aimed at prolonging pregnancy.