813: Changes of body composition in women with BMI≥25 included in a lifestyle program. Correlation with birthweight’s centile

Abstract

To evaluate if changes of body composition could affect the birthweight’s centile in overweight/obese women enrolled in an early lifestyle program. Two hundred and fourteen women with BMI≥25 were enrolled in an interventional study at 9th week, receiving a lifestyle program (hypocaloric, low-glycaemic index, low-saturated fat diet + specific physical activity recommendations). The tetrapolar bioelectrical impedance analysis (BIA) measured the gestational weight gain (GWG), the whole and regional fat mass (FM) and fat free mass (FFM), at enrolment and at 36th week. The primary outcome was the birthweigh’s centile. Age was 31.9±5.1 years (20-44). Most of women (78.6%) were Caucasian, pluriparous (61.9%) with a BMI of 43.6±5.9 (25.1-55.4). Obese of class I and II prevailed (62.4%) and 38 cases (17.7%) presented with BMI≥40. Those exceeding IOM recommendations (39.7%) had a significantly higher FM compared with those remaining into the ranges (5.5±3.6 vs 1.3±3.4 kg, p<0.001). Pre-pregnancy BMI didn’t show any correlation with birthweight’s centile. Both the GWG (p=0.01) and the changes in the FFM (p=0.002) (Figure), while not in the FM, at 36th week were correlated with the birthweight’s centile. The occurrence of GDM was 38.7% and these women had babies with significantly higher birthweight’s centile (p<0.001). After correcting for confounders (age, parity and pre-pregnancy BMI), the birthweight’s centile was independently associated with GDM (CR:14.9, p<0.0001), changes in FFM (CR:1.8, p=0.002) and, to a lesser extent, with GWG (CR:0.9, p=0.025). The rate of large for gestational age (LGA) and small for gestational age (SGA) babies are reported in the table. A reduction in FFM is associated with an increased risk of SGA babies (OR= 5.75, 95% CI: 1.59-20.87). GWG is a poor predictor of birthweight’s centile. Body composition changes, namely the decrease of the whole FFM, predict SGA babies in women submitted to a lifestyle program.View Large Image Figure ViewerDownload Hi-res image Download (PPT)