title: Maternal weight gain in twin-twin transfusion syndrome.
abstract: OBJECTIVE
  To examine the association between maternal weight gain and twin-twin transfusion syndrome (TTTS).
  
  
  METHODS
  Retrospective observational study in two tertiary care centers.
  
  
  METHODS
  All 124 women with monochorionic diamniotic twin pregnancies who gave birth at ≥ 16 gestational weeks between 2002 and 2010.
  
  
  METHODS
  Analysis of chronological relation between maternal weight gain per week (weekly gain) and the diagnosis of TTTS.
  
  
  METHODS
  Sonographic diagnosis of TTTS.
  
  
  RESULTS
  A weekly weight gain ≥ 1.4 kg occurred in 45 women, preceded the diagnosis of TTTS in 22 (78.6%) of the 28 women with TTTS, and was associated with TTTS [women with one weekly weight gain ≥ 1.4 kg vs. women with no weekly weight gains ≥1.4 kg who were diagnosed as having TTTS: 48.9% (22/45) vs. 7.6% (6/79); RR, 6.44; 95%CI, 2.82-14.69]. At given gestational weeks between 16 and 27, the mean (± SD) prospective risk of the development of TTTS within three weeks was 52.0 ± 33.8% among women who showed a weekly weight gain ≥ 1.4 kg for the first time, whereas the risk of the development of TTTS within one week was 1.6 ± 1.7% among women who never showed a weekly weight gain ≥ 1.4 kg.
  
  
  CONCLUSIONS
  Excessive maternal weight gain ≥ 1.4 kg/week is likely to occur during the development of TTTS.
authors.affiliation: Department of Obstetrics and Gynecology, Hokkaido University Graduate School of Medicine, Sapporo, Japan. mmamoru@med.hokudai.ac.jp
authors.forename: Mamoru
authors.initials: M
authors.lastname: Morikawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamada
authors.forename: Emi
authors.initials: E
authors.lastname: Hirayama-Kato
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamada
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Okuyama
authors.forename: Hisanori
authors.initials: H
authors.lastname: Minakami
mesh_terms: D000328:Adult; D005260:Female; D005330:Fetofetal Transfusion / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D006831:Polyhydramnios / Q000175:diagnosis / Q000209:etiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D014463:Ultrasonography; D015430:Weight Gain