The measurement of diastolic blood pressure during pregnancy: which Korotkoff phase should be used?
OBJECTIVE
The aim of this study was to compare the two Korotkoff phases, to estimate diastolic blood pressure during pregnancy.


METHODS
A cohort of 1194 nulliparous pregnant women were followed up prospectively from the twentieth week of pregnancy until delivery. Blood pressure measurements were obtained with random-zero sphygmomanometers at 20, 23, 25, 27, 31, and 35 weeks and then weekly until delivery. After 10 minutes of rest five blood pressure measurements were obtained in each position: supine, lateral, and seated. Korotkoff phases IV and V were obtained in each measurement.


RESULTS
The frequency of 0 values was always < 0.5% (n = 10,501 in each time and position). Mean differences between both phases throughout pregnancy fluctuates around 6 mm Hg. Minor differences (mean 3.7 mm Hg) without outlier values were observed in women with diastolic hypertension. Phase 5 showed a better association with other outcome variables related to hypertension, such as proteinuria, intrauterine growth retardation, and hyperuricemia.


CONCLUSIONS
Considering that phase 5 is easier to obtain, its use implies very few 0 values, that the difference between the two Korotkoff phases is around 6 mm Hg, and that the association with hypertension-related complications is similar to that of phase 4.
López
M C
MC
Centro Rosarino de Estudios Perinatales, Rosario, Argentina.
Belizán
J M
JM
Villar
J
J
Bergel
E
E
D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods*; D005260:Female; D005317:Fetal Growth Retardation / Q000150:complications; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000175:diagnosis; D016017:Odds Ratio; D011247:Pregnancy / Q000502:physiology*; D011248:Pregnancy Complications; D011249:Pregnancy Complications, Cardiovascular / Q000175:diagnosis; D011446:Prospective Studies; D011507:Proteinuria / Q000150:complications; D012680:Sensitivity and Specificity; D014527:Uric Acid / Q000097:blood
D014527:Uric Acid