THE DEFINITION OF PREECLAMPSIA

Background Redman and Jefferies have proposed a revised definition of pre-eclampsia which is based on absolute blood pressure levels and an increment from the baseline in the first half of pregnancy. There is n o requirement for proteinuria. This definition should facilitate the d istinction between nonproteinuric pre-eclampsia and other causes of no nproteinuric gestational hypertension, such as chronic essential hyper tension. Objectives 1. To determine whether the blood pressure criteri a of Redman and Jefferies can select women with characteristics of pre -eclampsia from the group of women with gestational hypertension by th e current criteria of the International Society for the Study of Hyper tension in Pregnancy (ISSHP). 2. To determine the level of agreement b etween the classification system proposed by Redman and Jefferies and that of the ISSHP. Design A prospective study. Setting Obstetric unit, Dudley Road Hospital, Birmingham, UK. Subjects Six hundred and ninety -two healthy nulliparous women and 11 women with chronic hypertension antedating pregnancy. Main outcome measures 1. Differences in maternal characteristics and obstetric outcome among women with gestational (n onproteinuric) hypertension by the ISSHP criteria, meeting (and failin g to meet) the Redman and Jefferies' blood pressure criteria. 2. The p roportion of women classified as normal, proteinuric pre-eclampsia, an d chronic hypertension on the basis of both Redman and Jefferies' crit eria and the current ISSHP criteria. Results There were 55 women with gestational hypertension alone by the ISSHP criteria, of whom 33 met R edman and Jefferies' blood pressure criteria for pre-eclampsia. This g roup of 33 women had characteristics of nonproteinuric pre-eclampsia, compared with the remaining 22 women in the ISSHP gestational hyperten sion category who had characteristics of chronic hypertension. The gro up of 33 were significantly younger and less obese, had significantly lower blood pressure at their first antenatal visit and their obstetri c outcome was poorer. The Redman and Jefferies' blood pressure criteri a identified as normal 99.5 % (95 % CI, 98.6 % to 99.9 %) of women who were also characterised as normal on the basis of the ISSHP criteria (622/625). There were 12 women with proteinuric pre-eclampsia by the I SSHP criteria of whom 11 (92 %; 95 % CI, 62 % to 99.8 %) met Redman an d Jefferies' blood pressure criteria for pre-eclampsia. None of the 11 women with chronic hypertension antedating pregnancy met these criter ia. Conclusions In this population the blood pressure criteria for pre -eclampsia proposed by Redman and Jefferies select women with features of pre-eclampsia (i.e., proteinuria and relatively poor outcome) and, in particular, they enable a distinction to be made between nonprotei nuric preeclampsia and other causes of gestational hypertension.