Objective To establish neonate rate models induced by high-fat diet so as to explore the effect of high-fat diet before and during pregnancy on growth and serum insulin-like growth factor-1 (IGF-1) level in neonate offspring.Methods Forty female SD rats were divided into high-fat group and control group that were fed with 35％ high-fat diet and standard chow,respectively.After 8 weeks,8 rats from each group were euthanatized for liver pathology and the other female rats were mated with male rats and fed continuously with 35％ high-fat diet and standard chow throughout gestation,respectively.Offspring from both groups were studied within 24 hours after birth.Their birth weight and body length (from apex nasi to end of tail) were measured.Enzyme-linked immunosorbent assay was used to detect serum IGF-1 level.Serum biochemical indexes were tested by biochemical analyzer.Liver pathologic changes were observed under the light microscope.The expression of IGF-1 in liver samples was detected by Western blot.Results 1.Rats in the high-fat group showed a significant less birth weight and shorter body length compared with those in the control group(all P ＜ 0.05).2.The level of serum IGF-1 of offspring in the high-fat group decreased by 20.1％ in comparison to offspring in the control group,but there was no significant difference between the 2 groups (P ＞ 0.05) because of the limited sample sizes.3.The aspartate transaminase(AST) of offspring in the high-fat group increased compared with those from control group(P ＜ 0.05),while other serum biochemical indexes between the 2 groups showed no significant differences(all P ＞0.05).4.Fatty degeneration could be found in livers of both dams and offspring in the high-fat group under light microscope,while the samples of both dams and offspring from the control group all showed normal.5.The IGF-1 expression in livers of offspring from high-fat group increased in comparison to that from control group(P ＜ 0.05).Conclusions A maternal high-fat diet before and during pregnancy decreases the birth weight and body length of offspring in utero,which may be associated with the decreased IGF-1.However,the pathogenesis of decreased IGF-1 in this study can not been found.Further study is needed to clarify the mechanism of intrauterine growth retardation induced by high-fat diet.