Measuring diastolic blood pressure in pregnancyBMJ 1996; 313 doi: https://doi.org/10.1136/bmj.313.7048.4 (Published 06 July 1996) Cite this as: BMJ 1996;313:4
- Peter Rubin
- Professor Department of Medicine, University Hospital, Queen's Medical Centre, Nottingham NG7 2UH
Use the fifth Korotkoff sound
The measurement of diastolic blood pressure during pregnancy offers plenty of scope for error. Most people still use a mercury sphygmomanometer, with all the pitfalls that are familiar outside obstetrics–“white coat” hypertension, digit preference, cuff size, differences between arms, and poorly calibrated equipment. To these should be added the influence of posture and gestation in a pregnant woman, so any advance in getting it right is to be welcomed. There is now good evidence to support using the fifth Korotkoff sound when measuring diastolic blood pressure in pregnancy.
Although measuring blood pressure and detecting hypertension remain at the core of antenatal monitoring, there has long been uncertainty about whether to record diastolic pressure as the point when the sounds muffle (Korotkoff phase IV) or when they disappear (phase V). The World Health Organisation recommends the use of phase IV,1 …