Diastolic Blood Pressure in Pregnancy: Phase Iv Or Phase V Korotkoff Sounds?

Abstract

Objective: To determine the magnitude of Phase IV-V diastolic blood pressure differences in human pregnancy.

Methods: Blood pressure was measured by a standardized technique, using a Hawkesley random zero sphygmomanometer, in 221 pregnant women. Measurements were made in the second and third trimesters of pregnancy. The study included a number of women with chronic hypertension and a number with preeclampsia.

Main Outcome Measures: Magnitude of Phase IV-V differences in normal and hypertensive pregnant women.

Results: As expected, values for Phase V diastolic blood pressure were lower than for those for Phase IV, both in the second and in the third trimesters of pregnancy. In the third trimester, the median difference between Phase IV and V Korotkoff sounds was 5 mm Hg in normals, 7 mm Hg in chronic hypertensives, and 5 mm Hg in women with preeclampsia.

Conclusion: These differences are within the error of the measurements as made in clinical practice. The smallest differences were found in women with preeclampsia, who are likely to provide the practitioner with the most difficult management decisions.

Key Words:

• Blood pressure
• Hypertension
• Pregnancy
• Sphygmomanometry