Pre‐Pregnancy Obesity and Weight Gain During Pregnancy: Relationship to the Development of Gestational Diabetes Mellitus and the Birth of a Large for Gestational Age Neonate

Abstract

Poster Presentation Objective To compare the prevalence of gestational diabetes mellitus (GDM) and large for gestational age (LGA) neonates in pregnant obese women who gain less than, within, and greater than the 2009 recommended weight gain guidelines of the Institute of Medicine (IOM). Design A retrospective cohort study. Setting Data from the University of North Carolina (UNC) Perinatal Database. Sample Women with singleton pregnancies and body mass indices (BMI kg/m2) ≥ 30 delivering between January 2012 and December 2012 who underwent routine screening for GDM at UNC Women's Hospital. Methods We measured the association between early weight gain (EWG) and diagnosis of GDM and the association between total gestational weight gain (TWG) and LGA neonate. To determine EWG and TWG, respectively, we subtracted prepregnancy weight from weight at GDM screening or weight at last prenatal visit >37 weeks. We calculated and classified EWG as less than, greater than, and within based on IOM guidelines for first trimester (1.1 pounds) and second trimester weekly weight gain (0.4‐0.6 pounds; 0.6 = above). Women were separately classified as gaining less than ( 20 pounds) IOM guidelines for TWG. We compared maternal demographics and medical history data using Pearson chi‐square and t test. We reported unadjusted and adjusted risk ratios (RR, aRR) with 95% confidence intervals (95%CI) for GDM and LGA with women gaining less than IOM guidelines as reference. Final adjusted models included prepregnancy BMI, EWG within guidelines, and gestational age at 1‐hour screening. Results Among 778 obese women, 67% (524/778) had full data for EWG analysis; 33% (171/524) gained less than, 17% (90/524) within, and 50% (263/524) greater than IOM recommendations. EWG adherence was not associated with a GDM diagnosis (p = .9). Seventy‐one percent (549/778) had full data for TWG analysis; 24% (130/549) gained less than, 20% (108/549) within, 55% (304/549) greater than IOM guidelines. Compared with women gaining less than, those gaining within IOM guidelines were more likely to have an LGA neonate (RR = 2.88, 95% CI 1.05‐7.95; aRR=3.36, 95% CI 1.10‐10.31). Compared with women gaining less than, those gaining greater than IOM recommendations were more likely to have an LGA neonate (RR = 3.25, 95% CI 1.30‐8.08; aRR=3.54, 95% CI 1.10‐11.79). Conclusion/Implications for Nursing Practice Among obese women, EGW adherence to IOM guidelines did not affect GDM diagnosis in our data. Total gestational weight gain within and greater than the IOM recommendations was associated with birth of LGA neonate. Using arenas of practice, health policy, and education nurses can assist in decreasing the incidence of LGA and GDM.