Outcomes
The primary outcome was late-onset preeclampsia, defined as new-onset hypertension accompanied by proteinuria after gestational week 34 (gestational day 237) irrespective of severity.18Details on the diagnostic criteria for hypertensive disorders of pregnancy in The Netherlands are outlined in Text S1.19 Data on the diagnosis of preeclampsia were obtained from previously validated questionnaires (sensitivity 88%, specificity 100%).20 In case of loss to follow-up, outcome data were extracted from obstetric records whenever possible.