title: Risk factors for preeclampsia in twin pregnancies.
abstract: OBJECTIVE
  Twin pregnancy is associated with an increased incidence of preeclampsia. However, it is unknown if the risk factors for preeclampsia in twin pregnancies are the same as those in singleton pregnancies.
  
  
  METHODS
  Case-control analysis of all twin pregnancies managed by one maternal-fetal medicine practice from 2005 to 2012. Patients with chronic hypertension were excluded, as were monochorionic-monoamniotic twins. We compared patient and pregnancy characteristics between patients who did and did not develop preeclampsia, according to standard American College of Obstetricians and Gynecologists definitions. Odds ratios, adjusted odds ratios (aORs), and 95% confidence intervals (CIs) were obtained using chi-square analysis and logistic regression.
  
  
  RESULTS
  Of the patients with twin pregnancies, 513 were included, and 76 (14.8%) patients developed preeclampsia. On univariable analysis, the risk factors associated with preeclampsia in twin pregnancies were egg donation, nonwhite race, nulliparity, prepregnancy obesity, and gestational diabetes. On adjusted analysis, the risk factors independently associated with preeclampsia were egg donation (aOR 2.409, 95% CI 1.051, 5.524) and prepregnancy obesity (aOR 2.367, 95% CI 1.079, 5.192).
  
  
  CONCLUSIONS
  In twin pregnancy, the risk factors independently associated with preeclampsia are egg donation and prepregnancy obesity.
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Science, Mount Sinai School of Medicine, New York, New York.
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Fox
authors.affiliation: Department of Obstetrics and Gynecology, NYU School of Medicine, New York, New York.
authors.forename: Ashley S
authors.initials: AS
authors.lastname: Roman
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Science, Mount Sinai School of Medicine, New York, New York.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Saltzman
authors.affiliation: Maternal Fetal Medicine Associates, PLLC, New York, New York.
authors.forename: Tanya
authors.initials: T
authors.lastname: Hourizadeh
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Science, Mount Sinai School of Medicine, New York, New York.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Hastings
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Science, Mount Sinai School of Medicine, New York, New York.
authors.forename: Andrei
authors.initials: A
authors.lastname: Rebarber
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D016640:Diabetes, Gestational; D005260:Female; D006801:Humans; D016015:Logistic Models; D009765:Obesity / Q000150:complications*; D018587:Oocyte Donation / Q000009:adverse effects*; D010298:Parity; D011225:Pre-Eclampsia / Q000453:epidemiology* / Q000208:ethnology; D011247:Pregnancy; D059285:Pregnancy, Twin; D012307:Risk Factors