Low pregnancy weight gain and small for gestational age: a comparison of the association using 3 different measures of small for gestational age.
OBJECTIVE
The purpose of this study was to assess associations between pregnancy weight gain (PWG) and small for gestational age (SGA) defined by birthweight < 10th percentile and 2 more restrictive definitions and to assess the proportion of SGA attributed to low PWG.


METHODS
This was a retrospective cohort study of 104,980 singleton, term births from the 2000-2005 Pregnancy Risk Assessment Monitoring System (PRAMS).


RESULTS
Compared with women who gained 15-25 lbs during pregnancy, women who gained 1-14 lbs had 1.5 greater odds (95% confidence interval, 1.2-1.8) of SGA for the most restrictive definition and 1.2 greater odds (95% confidence interval, 1.1-1.4) for the least restrictive definition, after adjustments for confounders. Depending upon the definition used, PWG below current Institute of Medicine recommendations contributed to 10-15% of SGA, representing 0.8-1.2% of all singleton term infants.


CONCLUSIONS
Associations between low PWG and SGA varied little by definition of SGA and contributed to only a small proportion of term SGA infants.
Dietz
Patricia M
PM
Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Callaghan
William M
WM
Smith
Ruben
R
Sharma
Andrea J
AJ
D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000502:physiology*; D009752:Nutritional Status; D016017:Odds Ratio; D011247:Pregnancy; D011256:Pregnancy Outcome; D012016:Reference Values; D012189:Retrospective Studies; D015430:Weight Gain / Q000502:physiology*