A Case-control Study Of Influencing Factors Of Low Birth Weight And Macrosomia

Objective: To explore influencing factors of low birth weight (LBW) and macrosomia. The objective of our research is to decrease the risk of LBW and macrosomia.Methods: The 1: 2 matched case-control study were conducted to research theinfluencing factors for LBW and macrosomia. 205 LBW and 212 macrosomia as cases were chosed with the questionnaire survey. And the controls were matched with cases by hospital, sex, area and the birth time within a week. We analyzed the data by conditional logistic regression. To adjust confounding factors, multivariate analysis was used for the statistical significant variables in single factor analysis. Final main effect functions were built through stepwise regression.Results: LBW related to maternal factors: BMI before pregnancy, weight gainduring whole pregnancy, mother's education level, exposure to poisonous and harmful material, smoking, chronic disease, age of menarche, abnormal pregnancy, gestational hypertension, gynecological inflammation, anomaly of placenta, premature rupture of membrane, anomaly of umbilical core, intake of nutritional supplement, points of exercise, daily intake of staple food, intake of increasing meat, intake times of fish and shrimp, hours of sleep, whether or not being single birth and gestational weeks. In addition, LBW related to paternal factors: occupation, smoking and chronic disease. Besides, family income is also a factor of LBW. Macrosomia related to maternal factors: BMI before pregnancy, weight gain during whole pregnancy, exposure to poisonous and harmful material, age of menarche, age of primiparity, gestational hypertension, whether or not being multiparity, gestational diabetes, polyhydramnios, daily intake of staple food, daily intake of meat, intake of oil per month and gestational weeks. In addition, smoking of father is also a factor of macrosomia. With stepwise regression, we found premature rupture of membrane, anomaly of placenta, gestational hypertension, whether or not being single birth, abnormal pregnancy, maternal BMI before pregnancy, weight gain during whole pregnancy, family income, smoking of mother, intake of nutritional supplement and mother's education level inter into final main effect functions of LBW. On the other hand, we found weight gain during whole pregnancy, daily intake of staple food, gestational weeks, gestational diabetes, BMI before pregnancy, smoking of father, whether or not being multiparity, daily intake of meat and age of menarche inter into final main effect functions of macrosomia.Conclusions: The potential factors include premature rupture of membrane, anomaly of placenta, gestational hypertension, whether or not being single birth, abnormal pregnancy, maternal BMI before pregnancy, weight gain during whole pregnancy, family income, smoking of mother, intake of nutritional supplement and mother's education level. These factors may be the influencing factors of LBW. And the factors including weight gain during whole pregnancy, daily intake of staple food, gestational weeks, gestational diabetes, BMI before pregnancy, smoking of father, whether or not being multiparity, daily intake of meat and age of menarche may be the influencing factors of macrosomia. We should take some effective ways to control the expose of these factors to decrease the occurrence LBW and macrosomia.