Protective factors for gestational weight gain

The adverse health effects of excessive gestational weight gain (GWG) have been documented for both mother and baby. Research has shown that GWG is influenced by several risk factors; however, there is limited research indicating protective factors for GWG. We assessed the protective factors associated with gaining within the recommended GWG guidelines according to the 1990 and 2009 IOM guidelines. We conducted a secondary analysis on data from a prospective cohort study of WIC participants based on interview and birth certificate data of women from 5 rural counties in the “bootheel” of Missouri and St. Louis city. The primary outcome was whether or not women had met the guidelines for GWG based on their pre-pregnancy BMI. Adjusted odds ratios and 95% confidence intervals (CI) were calculated using logistic regression analysis. Multiparous women were more likely to meet the 1990 (aOR=0.49;95%CI=0.31-0.77) and 2009 guidelines (aOR=0.57;95%CI=0.36-0.89). Pre-pregnancy BMI was also a significant protective factor for the 1990 guidelines. For every 1 unit increase in BMI, the odds of meeting the guidelines were 1.13 times higher (95%CI=1.09-1.16) compared to those with no change in BMI, suggesting that women entering pregnancy with greater weight for height are less likely to gain excessively than those with a lower BMI. These analyses suggest that pre-pregnancy weight should be targeted to reduce excessive GWG and women having a first birth should be education of a greater risk of excessive GWG. Further prospective studies should conduct a large-scale analysis to investigate additional protective factors for GWG.