胎儿为分娩三大要素之一。胎儿的大小与分娩直接相关,尤以胎头更为重要。近年来,国内外因头盆不称而行剖腹产者有上升趋势,我院统计近四年半剖腹产指征中,头盆不称为第二位,占剖腹产总数25％。所以,对足月眙儿体重、身长及胎头各径线进行生理常数调查,有重要意义。 The fetus is one of the three major elements of childbirth. The size of the fetus is directly related to childbirth, especially fetal head is more important. In recent years, caesarean at home and abroad due to cephalopelvic disproportion, there is an upward trend in our hospital statistics nearly four and a half years of caesarean section indications, cephalopelvic disproportionate second, accounting for 25% of the total number of caesarean section. Therefore, the full-term infant body weight, length and fetal diameter of the physiological constant survey, is of great significance.