Objectives: To examine the association between small for gestational age (SGA) and inadequate gestational weight gain (GWG) in obese women (compared with Institute of Medicine [IOM] guidelines) stratified by obesity classes.
Methods: We conducted a meta-analysis of original researches with sufficient information about inadequate GWG in obese women stratified by obesity classes. SGA as the chief outcome was extracted and assessed in our analysis. MEDLINE and EMBASE were searched through Ovid from 28 May 2009 to 1 December 2015. Quality was assessed using a modified Newcastle-Ottawa scale.
Results: 480 citations were screened and 13 studies (437 512 obese women) were included. Obese women who gained weight below the guidelines had higher risks of SGA than those who gained weight within the guidelines (OR 1.28; 95% CI 1.14-1.43). The same conclusions were also confirmed in Class I, Class II and Class III of obese women: Class I (OR 1.37; 95% CI 1.22-1.54); Class II (OR 1.38; 95% CI 1.24-1.54); Class III (OR 1.25; 95% CI 1.14-1.36).
Conclusions: From our analysis, the guidelines of IOM can be applied to all the classes of obesity. More accurate boundaries for each obesity class should be established to evaluate the maternal and fetal risks. Diverse populations are thus necessary for more studies in the future.
Keywords: Gestational weight gain; meta-analysis; obesity; small for gestational age.