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.