title: A model for preconceptional prediction of recurrent early-onset preeclampsia: derivation and internal validation.
abstract: OBJECTIVE
  To develop a model to identify women at very low risk of recurrent early-onset preeclampsia.
  
  
  METHODS
  We enrolled 407 women who had experienced early-onset preeclampsia in their first pregnancy, resulting in a delivery before 34 weeks' gestation. Preeclampsia was defined as hypertension (systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg) after 20 weeks' gestation with de novo proteinuria (≥300 mg urinary protein excretion/day). Based on the previous published evidence and expert opinion, 5 predictors (gestational age at previous birth, prior small-for-gestational-age newborn, fasting blood glucose, body mass index, and hypertension) were entered in a logistic regression model. Discrimination and calibration were evaluated after adjusting for overfitting by bootstrapping techniques.
  
  
  RESULTS
  Early-onset disease recurred in 28 (6.9%) of 407 women. The area under the receiver operating characteristic (ROC) curve of the model was 0.65 (95% CI: 0.56-0.74). Calibration was good, indicated by a nonsignificant Hosmer-Lemeshow test (P = .11). Using a predicted absolute risk threshold of, for example, 4.6% (ie, women identified with an estimated risk either above or below 4.6%), the sensitivity was 100%, with a specificity of 26%. In such a strategy, no women who developed preeclampsia were missed, while 98 of the 407 women would be regarded as low risk of recurrent early-onset preeclampsia, not necessarily requiring intensified antenatal care.
  
  
  CONCLUSIONS
  Our model may be helpful in the identification of women at very low risk of recurrent early-onset preeclampsia. Before widespread application, our model should be validated in other populations.
authors.affiliation: Department of Obstetrics and Gynecology, Maastricht University Medical Center, Maastricht, Netherlands. sander.vankuijk@epid.unimaas.nl
authors.forename: Sander M J
authors.initials: SM
authors.lastname: van Kuijk
authors.forename: Marie-Elise
authors.initials: ME
authors.lastname: Nijdam
authors.forename: Kristel J M
authors.initials: KJ
authors.lastname: Janssen
authors.forename: Simone J S
authors.initials: SJ
authors.lastname: Sep
authors.forename: Louis L
authors.initials: LL
authors.lastname: Peeters
authors.forename: Denise H J
authors.initials: DH
authors.lastname: Delahaije
authors.forename: Marc
authors.initials: M
authors.lastname: Spaanderman
authors.forename: Hein W
authors.initials: HW
authors.lastname: Bruinse
authors.forename: Arie
authors.initials: A
authors.lastname: Franx
authors.forename: Michiel L
authors.initials: ML
authors.lastname: Bots
authors.forename: Josje
authors.initials: J
authors.lastname: Langenveld
authors.forename: Joris
authors.initials: J
authors.lastname: van der Post
authors.forename: Bas B
authors.initials: BB
authors.lastname: van Rijn
authors.forename: Luc
authors.initials: L
authors.lastname: Smits
mesh_terms: D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D005215:Fasting; D005260:Female; D005865:Gestational Age; D006801:Humans; D006973:Hypertension; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D016015:Logistic Models; D011225:Pre-Eclampsia / Q000175:diagnosis*; D016742:Preconception Care; D011247:Pregnancy; D012372:ROC Curve; D012008:Recurrence; D015203:Reproducibility of Results
chemical_list: D001786:Blood Glucose