The impact of pre‐eclampsia definitions on the identification of adverse outcome risk in hypertensive pregnancy – analyses from the CHIPS trial (Control of Hypertension in Pregnancy Study) Academic Article uri icon

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  • OBJECTIVE: To examine the association between pre-eclampsia definition and pregnancy outcome. DESIGN: Secondary analysis of Control of Hypertension in Pregnancy Study (CHIPS) trial data. SETTING: International multicentre randomised controlled trial (RCT). POPULATION: In all, 987 women with non-severe non-proteinuric pregnancy hypertension. METHODS: We evaluated the association between pre-eclampsia definitions and adverse pregnancy outcomes, stratified by hypertension type and blood pressure control. MAIN OUTCOME MEASURES: Main CHIPS trial outcomes: primary (perinatal loss or high-level neonatal care for >48 hours), secondary (serious maternal complications), birthweight <10th centile, severe maternal hypertension, delivery at <34 or <37 weeks, and maternal hospitalisation before birth. RESULTS: Of 979/987 women with informative data, 280 (28.6%) progressed to pre-eclampsia defined restrictively by new proteinuria, and 471 (48.1%) to pre-eclampsia defined broadly as proteinuria or one/more maternal symptoms, signs or abnormal laboratory tests. The broad (versus restrictive) definition had significantly higher sensitivities (range 62-79% versus 36-50%), lower specificities (range 53-65% versus 72-82%), and similar or higher diagnostic odds ratios and 'true-positive' to 'false-positive' ratios. Stratified analyses showed similar results. Addition of available fetoplacental manifestations (stillbirth or birthweight <10th centile) to the broad pre-eclampsia definition improved sensitivity (74-87%). CONCLUSIONS: A broad (versus restrictive) pre-eclampsia definition better identifies women who develop adverse pregnancy outcomes. These findings should be replicated in a prospective study within routine healthcare to ensure that the anticipated increase in surveillance and intervention in a larger number of women with pre-eclampsia is associated with improved outcomes, reasonable costs and congruence with women's values. TWEETABLE ABSTRACT: A broad (versus restrictive) pre-eclampsia definition better identifies the risk of adverse pregnancy outcomes.


  • Magee, LA
  • Singer, J
  • Lee, T
  • Rey, E
  • Asztalos, E
  • Hutton, Eileen Katherine
  • Helewa, M
  • Logan, AG
  • Ganzevoort, W
  • Welch, R
  • Thornton, JG
  • Woo Kinshella, ML
  • Green, M
  • Tsigas, E
  • Dadelszen, P

publication date

  • July 2021