Inter‐arm blood pressure differences in pregnant women

Abstract

Objective To determine the prevalence of blood pressure interarm difference (IAD) in early pregnancy and to investigate its possible association with maternal characteristics.Design A cross-sectional observational study.Setting Routine antenatal visit in a university hospital.Population A total of 5435 pregnant women at 11-14 weeks of gestation.Methods Blood pressure was taken from both arms simultaneously with a validated automated device.Main outcome measures The presence of inter-arm blood pressure difference of 10 mmHg or more.Results The IAD in systolic and diastolic blood pressure was 10 mmHg or more in 8.3 and 2.3% of the women, respectively. Systolic IAD was found to be significantly related to systolic blood pressure and pulse pressure, and diastolic IAD was found to be significantly related to maternal age, diastolic blood pressure and pulse pressure. The systolic and diastolic IAD were higher in the hypertensive group compared with the normotensive group and absolute IAD increased with increasing blood pressure. About 31.0 and 23.9% of cases of hypertension would have been underreported if the left arm and the right arm were used, respectively, in measuring the blood pressure.Conclusions There is a blood pressure IAD in a significant proportion of the pregnant population, and its prevalence increases with increasing blood pressure. By measuring blood pressure only on one arm, there is a one in three chance of underreporting hypertension. Therefore, it would be prudent that during the booking visit blood pressure should be taken in both arms and thus provide guidance for subsequent blood pressure measurements during the course of pregnancy.

Blood Pressure Measurement Method and Inter-Arm Differences: A Meta-Analysis

“…Kolmogorov-Smirnov analysis showed that the IAD prevalences were not normally distributed methods of BP measurements Tables 2 and 3 provide differences between groups separated for measurement methods (simultaneous vs. sequential measurements), device (manual vs. automatic) and the number of readings (1 vs. 2 or more readings) used to determine IAD prevalences ( Table 2), average and absolute IAD values ( Table 3). There were 12 studies 8,9,13,14,17,18,24,26,28,29,31,32 (n = 8,853) in which simultaneous measurements and 12 studies 13,14,16,[19][20][21][22][23]25,27,30,33 (n = 6,001) in which sequential measurements were performed, which means that in two studies 13,14 both methods were assessed. In 14 studies an automated oscillometric device 8,9,13,14,[17][18][19][26][27][28][29][30][31][32] (n = 12,644) was used for IAD determination, in seven studies 9,17,20,27,…”

“…8,9,13,16-20,23-33) (n = 14,047) and 13 studies 9,16,17,[19][20][21][22]25,27,29,30,32,33 (n = 6,508), respectively. Seventeen studies 8,9,16,17,[19][20][21][22]24,25,[27][28][29][30][31][32][33] (n = 12,956) showed the number of subjects with a diastolic IAD ≥10 mm Hg and six studies 9,17,20,27,32,33 (n = 4,447) a diastolic IAD ≥20 mm Hg. Systolic IAD values (right-left BP values) were provided or could be calculated in 11 studies 9,14,17,21,25,28-33 (n = 8,109).…”

“…BP measurement was predominantly performed in a sitting position but four studies reported supine position. [16][17][18][19] BP was measured with a standard mercury device, 14,20-25 an aneroid device, 16 an automated oscillometric device 8,9,13,14,[17][18][19][26][27][28][29][30][31][32] and an automated auscultatory device. 33 Of the automated devices used in the included studies in all but 4 (refs.…”

Blood pressure measurement in pregnancy

“…6 They also noted that the prevalence and magnitude of inter-arm variation increases with increasing blood pressure. The authors have concluded that by measuring blood pressure in one arm only, there is a chance of underreporting hypertension.…”

“…Poon et al have introduced us to another variable-which arm was interrogated-that can influence our ability to predict and prevent eclampsia and its sequelae. 6 Despite these shortcomings, office-based blood pressure measurement is the standard for screening for hypertensive disorders in pregnancy. This detection method has been the entry point for all the epidemiological studies and treatment trials performed up to this point.…”