To analyze influencing factors of fetal macrosomia in order to predict fetal macrosomia and select the appropriate mode of delivery.

From January to December 2012,a total of 429 cases of fetal macrosomia (birth weight ≥ 4 000g ) were analyzed retrospectively as research group (n= 429). Meanwhile 429 cases normal newborn (birth weight 2 500g~4 000g ) delivered in the same time were selected as control group(n = 429). The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Hospital of Maternity and Children of Foshan. Informed consent was obtained from each participants. Clinical data of maternal age, height, gestational weeks at delivery, parity, maternal body weight in the 20th gestational week and before delivering, height of uterus, maternal abdominal circle, biparietal diameter (BPD), femur length (FL), gender of fetus, whether combined with hydramnion and gestational diabetes mellitus(GDM) or not,and delivery pattern were compared between two groups.

There were significant differences between two groups in macrosomia, maternal age, height, gestational weeks at delivery, parity, maternal body weight in the 20th week pregnancy and before delivering, weight gain during pregnancy, height of uterus, maternal abdominal circle, BPD and FL(P< 0.05). The incidence rate of male fetal macrosomia was 1.84 times as much as female in research group. The incidence rates of hydramnion and GDM were obviously higher than those of control group (P <0.05). There was significant difference in cesarean section rate between two groups ( P < 0.05 ).

Maternal age, height, weight, gestational weeks at delivery, parity, height of uterus, maternal abdominal circle, combined with hydramnion or GDM are influencing factors of fetal macrosomia. Gravidogram and ultrasound may contribute to prenatal diagnosis of fetal macrosomia.