Background
: Low birth weight and high birth weight are closely related to prenatal complications. The purpose of this study is to estimate the association of prepregnancy weight, maternal weight gain and infant birth weight.

Methods : The effect on birth weight in 724 live births after 38~42 weeks gestation was studied at Taegu Medical Center, between January, 1997, and August, 1998. Pregnant women with hypertension, diabetes mellitus, multiple pregnancy and drug abuse were excluded because of their possible influence on birth weight. To study the effect on infant birth weight, multiple regression analysis was carried out.

Results : We evaluated 724 pregnant women and their babies. Mean prepregnancy weight was 52.2±6.9kg, mean maternal weight gain was 13.0±4.6kg, and mean BMI(Body Mass Index) was 20.5±w.5kg/m². Mean gestational age was 278±7.3days and mean birth weight was 3,320.5±405.2gm. Cor-relation coefficient between birth weight and prepregnancy weight was 0.347(p<0.01), and maternal weight gain was 0.248(p<0.01), and BMI(Body Mass Index) was 0.261(p<0.01). Birth weight was significantly correlated with prepregnancy weight(p<0.01) and maternal weight gain(p<0.01), but prepregnancy weight was not significantly correlated with maternal weight gain(p≥0.05). Prepregnancy weight had most apparent influence on birth weight.

Conclusion : Prepregnancy weight and maternal weight gain was positively related to birth weight. These results suggest that there are good effects of properly controlling prepregnancy weight and maternal weight gain in pregnant women and their babies.