A diagnosis of pre-eclampsia identifies women and babies who could benefit from close follow-up, medication (including that to lower blood pressure), and/or earlier birth. In 2019, UK guidelines for high blood pressure in pregnancy changed the definition of pre-eclampsia, from one that required new protein in the urine to one that could include new protein in the urine, but did not have to if there is evidence of other relevant problems (such as high liver tests). Using data from 987 women with chronic (pre-existing) or gestational (pregnancy-induced) high blood pressure in pregnancy from a large international trial of blood pressure management – CHIPS (Control of Hypertension In Pregnancy Study) – we found that more women were diagnosed with pre-eclampsia by the new definition (48%) than with the old (29%). However, the new definition better identified mothers and babies who developed pregnancy complications. What do you think of these results? Tweet: @LauraAMagee1