title: Timing of Excessive Weight Gain During Pregnancy Modulates Newborn Anthropometry.
abstract: OBJECTIVE
  Excessive gestational weight gain (GWG) is associated with increased birth weight and neonatal adiposity. However, timing of excessive GWG may have a differential impact on birth outcomes. The objective of this study was to compare the effect of early and mid/late excessive GWG on newborn anthropometry in the context of the Canadian clinical recommendations that are specific for first trimester and for second/third trimesters based on maternal pre-pregnancy BMI.
  
  
  METHODS
  We included 607 glucose-tolerant women in our main analyses, after excluding women who had less than the recommended total GWG. Maternal body weight was measured in early pregnancy, mid-pregnancy, and late pregnancy. Maternal and fetal clinical outcomes were collected, including newborn anthropometry. Women were divided into four groups according to the Canadian guidelines for GWG in the first and in the second/third trimesters: (1) "overall non-excessive" (reference group); (2) "early excessive GWG"; (3) "mid/late excessive GWG"; and (4) "overall excessive GWG." Differences in newborn anthropometry were tested across GWG categories.
  
  
  RESULTS
  Women had a mean (±SD) pre-pregnancy BMI of 24.7 ± 5.2 kg/m(2) and total GWG of 15.3 ± 4.4 kg. Women with mid/late excessive GWG gave birth to heavier babies (gestational age-adjusted birth weight z-score 0.33 ± 0.91) compared with women in the reference group (0.00 ± 0.77, P = 0.007), whereas women with early excessive GWG gave birth to babies of similar weight (gestational age-adjusted z-score 0.01 ± 0.86) to the reference group (0.00 ± 0.77, P = 0.84). When we stratified our analyses and investigated women who gained within the recommendations for total GWG, mid/late excessive GWG specifically was associated with greater newborn size, similar to our main analyses.
  
  
  CONCLUSIONS
  Excessive GWG in mid/late pregnancy in women who did not gain weight excessively in early pregnancy is associated with increased birth size, even in those who gained within the Canadian recommendations for total GWG.
authors.affiliation: Department of Biochemistry, Université de Sherbrooke, Sherbrooke QC; ECOGENE-21, Chicoutimi Hospital, Chicoutimi QC.
authors.forename: Stephanie-May
authors.initials: SM
authors.lastname: Ruchat
authors.affiliation: Department of Mathematics, Université de Sherbrooke, Sherbrooke QC.
authors.forename: Catherine
authors.initials: C
authors.lastname: Allard
authors.affiliation: Centre de recherche du CHUS, Sherbrooke QC.
authors.forename: Myriam
authors.initials: M
authors.lastname: Doyon
authors.affiliation: Department of Medicine, Université de Sherbrooke, Sherbrooke QC.
authors.forename: Marilyn
authors.initials: M
authors.lastname: Lacroix
authors.affiliation: Department of Medicine, Université de Sherbrooke, Sherbrooke QC.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Guillemette
authors.affiliation: Department of Medicine, Université de Sherbrooke, Sherbrooke QC.
authors.forename: Julie
authors.initials: J
authors.lastname: Patenaude
authors.affiliation: Department of Medicine, Université de Sherbrooke, Sherbrooke QC.
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Battista
authors.affiliation: Department of Medicine, Université de Sherbrooke, Sherbrooke QC.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Ardilouze
authors.affiliation: ECOGENE-21, Chicoutimi Hospital, Chicoutimi QC; Department of Medicine, Université de Sherbrooke, Sherbrooke QC.
authors.forename: Patrice
authors.initials: P
authors.lastname: Perron
authors.affiliation: Department of Biochemistry, Université de Sherbrooke, Sherbrooke QC; ECOGENE-21, Chicoutimi Hospital, Chicoutimi QC.
authors.forename: Luigi
authors.initials: L
authors.lastname: Bouchard
authors.affiliation: Department of Medicine, Université de Sherbrooke, Sherbrooke QC; Department of Population Medicine, Harvard Pilgrim Health Care Institute, Boston MA; Massachusetts General Hospital, Boston MA.
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Hivert
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000502:physiology*; D001835:Body Weight / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy / Q000706:statistics & numerical data*; D011446:Prospective Studies; D015430:Weight Gain / Q000502:physiology*; D055815:Young Adult
keywords: Gestational weight gain; excessive; newborn anthropometry; timing