Cytogenetic effects of oral Contraceptive pills during pregnancy on some aspects of fetus and newborn in mice

The cytogenetic effects of taking oral contraceptive pills OCPs that contain steroid hormones (estrogen and progesterone) during pregnancy on some aspects of fetus and newborn have been previously reviewed. The objectives of this study are to detect the effect of using different doses of progestin and estrogen by pregnant female mice on the chromosomal aberration CAs and mitotic index MI in their male fetuses. Thirty female mice were divided equally into three major groups: two experimental G1 and G2 and control group according to the level of the dose. Administration of COCPs (either 0.034 or 0.068 mg/kg b. wt. /d dissolved with 0.1ml distilled water) orally once a day, were started at the first day of gestation and continued till day 14 for the experimental groups G1and G2 respectively. When the new pups in each experimental and control group reach two weeks of age, those male offspring 10animals/ group were used for chromosome preparation, while the control group divided into two groups: ten animals represented a negative control given distilled water only, while the other ten animals injected intra peritoneal with mitomycin–C 2mg/Kg represented positive control (once dose). The statistical analysis of mice bone marrow cells have no significant decrease in the mitotic index of the pups belongs to G1 mothers in comparison with negative control group, but it shows a highly significant differences P<0.01 as compared with that of positive control group . Although the pups belong to G2 mothers showed a slight decrease in the mitotic index in comparison with negative control group. Differences were non- significant with negative control and highly significant P<0.01 with positive control group. In addition, the mitotic index of spleen cells of the pups belongs to G1 mothers noticed no significant decrease in comparison with negative control group, however, it shows a significant differences P< 0.05 as compared with positive control group. In the pups belongs to G2 mothers there were significant decrease P< 0.05 in mitotic index in comparison with negative and positive control groups. The results showed that the COCPs caused an increase in chromosomal aberrations CAs with increasing of steroid hormones concentration. In G1 group the CA equal to 19.91%. This reducing in CA was not significant in comparison with those of the negative control which gave 14.33%; this percentage was increased in the result of CAs of the mice treated with mitomycin –C (MMC) which was 48.58%. Treatment with 0.068 mg/kg B wt. of COCPs gave CA equal to 17.18%. This value was not significant in comparison with those of the negative control which was 19.91%. Higher doses of OCPs may cause cytogenetic effects in chromosomal aberrations CAs and decrease the mitotic index (MI) in the bone marrow cells and spleen cells of offspring belonged to mothers treated with oral contraceptive during their pregnancy for 14 days.