title: Clinical usefulness of maternal body mass index in twin pregnancies.
abstract: OBJECTIVE
  We examined whether maternal body mass index (BMI) during prepregnancy is useful for prediction of maternal preeclampsia in twin pregnancies.
  
  
  METHODS
  We studied 250 dichorionic twin pregnancies and 3196 singleton pregnancies. Maternal BMI was calculated during prepregnancy in both twin and singleton pregnancies. The incidence of maternal preeclampsia was compared among three groups, low-BMI [< -1.5 standard deviations (SD)], normal-BMI, and high-BMI (> + 1.5 SD) groups, in both singleton and twin pregnancies.
  
  
  RESULTS
  In singleton pregnancies, the incidence of maternal preeclampsia in the high-BMI group was significantly higher than that in the normal-BMI group (p < 0.05). The relative risk by high BMI was 8.5 (95% confidence interval: 5.6-12.0). However, in twin pregnancies, no significant differences were observed in these values.
  
  
  CONCLUSIONS
  Body mass index during prepregnancy was not useful for the prediction of preeclampsia in twin pregnancies. Mechanisms other than maternal weight may be associated with the beginning of preeclampsia in twin pregnancies.
authors: Department of Obstetrics and Gynecology, Nippon Medical School, Tokyo, Japan.
authors: S
authors: S
authors: Suzuki
authors: Y
authors: Y
authors: Yoneyama
authors: R
authors: R
authors: Sawa
authors: S
authors: S
authors: Shin
authors: T
authors: T
authors: Araki
mesh_terms: D000328:Adult; D001724:Birth Weight; D015992:Body Mass Index; D005260:Female; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D009017:Morbidity; D009035:Mothers; D010298:Parity; D011225:Pre-Eclampsia / Q000175:diagnosis* / Q000209:etiology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology; D011379:Prognosis; D012306:Risk; D012307:Risk Factors; D014430:Twins, Monozygotic