Abstract: Objective: To investigate the relationship between visfatin levels in maternal serum and umbilical core serum and birth weight. Methods: According to newborn birth weight, sixty cases of pregnancy ｗｏｍｅｎ ｉｎ ｌａｔｅ ｔｒｉｍｅｓｔｅｒ ｗｅｒｅ ｄｉｖｉｄｅｄ ｔｏ ｔｈｒｅｅ ｇｒｏｕｐｓ： ｓｍａｌｌ ｆｏｒ ｇｅｓｔａｔｉｏｎａｌ ａｇｅ（ＳＧＡ）， ａｐｐｒｏｐｒｉａｔｅ ｆｏｒ ｇｅｓｔａｔｉｏｎａｌ ａｇｅ（ＡＧＡ）， ｌａｒｇｅ ｆｏｒ ｇｅｓｔａｔｉｏｎａｌ ａｇｅ（ＬＧＡ）． Ｆａｓｔ?鄄ｂｌｏod samples were collected on the day of elective caesarean section, sera visfatin was analysed by ELISA. Newborn birth weight was recorded. Statistical analysis was made by SPSS17.0. Results: The visfatin concentrations in maternal serum of SGA， AGA and LGA group were statistically significant（Ｆ＝５００．０４， Ｐ＜０．０５）； similar increase of visfatin level was found in umbilical core serum of SGA, AGA and LGA group（Ｆ＝３５４．６９， Ｐ＜０．０５）． The positive correlation was found between newborn birth weight and the visfatin concentration in maternal serum or umbilical core（ｒ＝０．５２８ ａｎｄ ｒ＝０．６０９， ｒｅｓｐｅｃｔｉｖｅｌｙ， Ｐ＜０．０５）. Conclusions: Visfatin, a new fat factor, participates in the regulation of fetal growth in uterus. It can be used as a marker of fetal weight.

Key words: Pregnancy, Nicotinamide phosphoribosyltransferase, Birth weight, Enzyme?鄄linked immunosorbent assay