1. Ahmed Group Lecture 28 Effects of Radiation on the Embryo and Fetus Lecture 28

2. Ahmed Group Lecture 28 Intrauterine death Congenital abnormalities and neonatal death Microcephaly, mental retardation Growth retardation Dose, dose rate, and stage in gestation Human experience of pregnant women exposed to therapeutic dose

3. Ahmed Group Lecture 28 Three important stages of development 1.Pre-implantation 2.Organogenesis 3.Fetal development Newly fertilized mouse egg 3 rd day –mouse embryo

4. Ahmed Group Lecture 28 Classic effects of radiation on Embryo and Fetus 1.Lethal effects pre-implantation death intra-uterine death neonatal death 2.Malformations Teratogenic effects 3.Growth disturbances Effects depend on: Dose, Stage of gestation and dose rate

5. Ahmed Group Lecture 28 Dose= 2 Gy

6. Ahmed Group Lecture 28 Intrauterine death Congenital abnormalities and neonatal death Microcephaly, mental retardation Growth retardation Dose, dose rate, and stage in gestation Human experience of pregnant women exposed to therapeutic dose

7. Ahmed Group Lecture 28 (1 Gy) Congenital malformations

8. Ahmed Group Lecture 28 Resorbed fetuses Irradiation during the period of organogenesis Normal

9. Ahmed Group Lecture 28 Irradiation during the period of organogenesis Eye defects

10. Ahmed Group Lecture 28 Intrauterine death Congenital abnormalities and neonatal death Microcephaly, mental retardation Growth retardation Dose, dose rate, and stage in gestation Human experience of pregnant women exposed to therapeutic dose

11. Ahmed Group Lecture 28 Experience in humans 1.Medical exposures 2.Atomic bomb survivors Effects: 1.Microcephaly 2.CNS defects 3.Growth retardation For period 16-25 weeks Absorbed fetal dose (Rads)

12. Ahmed Group Lecture 28 Medical Radiation effects on Embryo and Fetus 1.Less severe abnormalities in human embryo exposed before 2-3 weeks of gestation was observed, although an increase abortion was reported. 2.Severe abnormalities observed between 4 and 11 weeks of gestation. 3.Abnormalities involving eye, skeleton, genital organs and stunted growth, microcephaly and mental retardation was observed between 11 and 16 weeks of gestation. 4.Weeks 16-20 showed mild stunted growth, microcephaly and mental retardation. 5.Irradiation after 30 weeks caused functional disabilites.

13. Ahmed Group Lecture 28 Intrauterine death Congenital abnormalities and neonatal death Microcephaly, mental retardation Growth retardation Dose, dose rate, and stage in gestation Human experience of pregnant women exposed to therapeutic dose

14. Ahmed Group Lecture 28 Comparison of human and animal data

15. Ahmed Group Lecture 28

16. Ahmed Group Lecture 28

17. Ahmed Group Lecture 28