ABSTRACT
Objective To observe the correlation between mating days and pregnancy rate, the vaginal pessary number and the embryos number in female rats, for facilitating the whole planning of the relevant experiments. Methods 70 female Wistar rats were randomly mated with 20 male Wistar rats separately. Mating days and vaginal pessary were recorded. In late stage of the experiment, the number of pregnant rats and embryos were confirmed by post-mortem anatomy. Results Person correlation coefficient of the mating days and pregnancy rate in exhausting pessary rats was 0.83, P<0.05 (P=0.005); person correlation coefficient of the vaginal pessay number and the embryos was 0.16, P>0.05(P=0.18). Conclusion There was linearly dependent relationship between the mating days and pregnancy rate, the pregnancy rate of female rats become 100% when the mating days reached 4 days. But there was no such relationship between the vaginal pessary and the embryo number.