Risk factors for preeclampsia in twin pregnancies

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.