Objective     To investigate the effects of nordihydroguaiaretic acid (NDGA) on the embryos growth and decidualization of rat by intrauterine perfusion and to investigate the new medication for planned parenthood.      Methods     Fifty-six pregnant SD rats were randomly divided into NDGA-treated group (N) and PBS-treated control group (P) and blank control group (B). By intubation

NDGA or PBS was perfused into the uterus on embryonic day 1 (E1) and day 7 (E7). Rats were killed on E9 to calculate the number and measure the diameter of the embryos

as well as the number and weight of litters. The expression of VEGF

PCNA and FⅧRAg in deciduas and placenta were detected by immunohistochemistry and image analysis. The serum concentration of progesterone on E9 was measured.      Results     In comparison with two control groups

the number and the diameter of embryos after perfusion were decreased with NDGA treatment on E1 (P0.05). The number of full-term fetus was decreased (P0.05).The diameter of embryos after perfusion with NDGA  on E7 was significantly diminished (P0.05).The expression of VEGF

PCNA and FⅧRAg in the deciduas and placenta were all reduced (P0.01). The serum concentration of progesterone on E9 was not significantly different from that of control groups (P0.05).       Conclusion     NDGA can inhibit the growth of early embryo and interfere with the progress of decidualization obviously by intrauterine perfusion

but has little effect on the serum concentration of progesterone.