Objective To investigate the effect of in utero intraperitoneal injection of human tumor HepG2 cells on the growth and development of fetal mice. Methods Pregnant mice were randomly divided into five groups and various densities of HepG2 cell suspensions were injected into the fetus by intrauterine injection at embryonic day 14. Sham operation and control groups were included. Pregnancies and the body weight of offspring were recorded, and developmental indicators were evaluated. Adult mice were selected and dissected to observe malformations and pathological changes in major organs including the liver, lungs, and kidneys. Results There was no significant difference in the growth or development of offspring in HepG2 cell injection and control groups. There were no lesions in major organs based on macroscopic and microstructural observations. Conclusions In utero intraperitoneal injection of human tumor HepG2 cells has no effect on the development of fetal mice.