title: Gestational weight gain according to number of fetuses in Japanese women.
abstract: OBJECTIVE
  It is unknown whether weekly maternal weight gain differs between Japanese women with singleton, twin, and triplet pregnancies.
  
  
  METHODS
  Gestational weight gain defined as net weight gain during pregnancy was analyzed in 135,036 pregnant Japanese women, including 128,838 with singletons, 5573 with twins, and 132 with triplets, who gave birth at ≥22 weeks of gestation between 2007 and 2009. Weekly weight gain was defined as follows: gestational weight gain÷[gestational week (GW) at Delivery-2].
  
  
  RESULTS
  Length of gestation (weeks, mean±SD) decreased significantly (38.2±2.6, 35.3±3.0, and 32.7±2.8) with increasing number of fetuses, while overall gestational weight gain (kg) was significantly smaller in women with singletons than in those with either twins or triplets (9.6±4.4 vs. 10.9±4.8 or 10.9±5.2, respectively). Thus, weekly maternal weight gain (kg/week) increased significantly with increasing number of fetuses (0.26±0.12, 0.33±0.13, and 0.35±0.16). Among women with delivery at or after GW 34, difference in gestational weight gain (kg) was prominent between the three groups (9.8±4.4, 11.4±4.7, and 13.0±5.1 for singleton, twin, and triplet pregnancies, respectively, P<0.001 between any two groups).
  
  
  CONCLUSIONS
  Weekly maternal weight gain increases with increasing number of fetuses. Our figures may be useful for advising Japanese women with multifetal pregnancies regarding gestational weight gain.
authors: Mamoru
authors: M
authors: Morikawa
authors: Takahiro
authors: T
authors: Yamada
authors: Rina
authors: R
authors: Akaishi
authors: Takashi
authors: T
authors: Yamada
authors: Ryutaro
authors: R
authors: Nishida
authors: Shoji
authors: S
authors: Sato
authors: Masanori
authors: M
authors: Kaneuchi
authors: Hisanori
authors: H
authors: Minakami
mesh_terms: D000328:Adult; D001724:Birth Weight; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D036861:Delivery, Obstetric; D005260:Female; D005865:Gestational Age; D006801:Humans; D007564:Japan; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000502:physiology*; D059286:Pregnancy, Triplet / Q000502:physiology; D059285:Pregnancy, Twin / Q000502:physiology; D014310:Triplets; D014427:Twins; D015430:Weight Gain