Association Between Pre-pregnancy Body Mass Index and Maternal Weight Gain and Birth Weight

Abstract

Objective To analyze the relationship among pre-pregnancy body mass index(BMI), gestational weight gain and birth weight. Methods From July 2006 to June 2007, 2734 pregnant women who delivered in the department of Obstetrics and Gynecology, West China Second Hospital of Sichuan University were enrolled in this study. They were divided into low BMI group(BMI 23.71 kg/m2,n=353) based on the pre-pregnancy body mass index. In normal BMI group, patients were further divided into 3 subgroups according to the gestational weight gain, 20.25 kg group. The relationship among pre-pregnancy body mass index, gestational weight gain and birth weight in each group were analyzed. Results The correlation coefficient(r) of body mass index to birth weight in low BMI group, normal BMI group and high BMI group was 0.128(P>0.05), 0.138(P 0.05), so did the association between the incidence of muaorosomia and gestational weight gain in high BMI group (P>0.05). Conclusion Pre-pregnancy body mass index and gestational weight gain had a positive correlation to birth weight. In order to decrease the incidence of macrosomia, gestational weight gain should be limited below 20.25 kg. Key words: pre-pregnancy body mass index(pre-pregnancy BMI); gestational weight gain; birth weight