Tooth formation of the primary teeth begins at 11 to 14 weeks of fetal life and is completed postnatally. The enamel of the primary teeth begins to develop at 10 weeks and gradually continues to develop throughout pregnancy; enamel development on the permanent teeth starts in week 28 and begins to mineralize at the time of birth. It is known that both tetracycline and antiepileptic medications use during pregnancy can affect tooth development. For example, prenatal exposure tetracycline induces discoloration of deciduous teeth, while exposure to antiepileptic drugs increases the risk of enamel opacities and hypoplasia. Enamel hypoplasia increases susceptibility for primary dental caries due to an increased risk for bacterial colonization. Peretz et al in 2003 reported the dental examination of 2 children exposed to Doxorubicin+/-Cyclophosphamide during the third trimester for breast cancer. Both children at 18 and 30 months of age had normal primary teeth. Three women in the Cancer and Pregnancy Registry have reported dental issues in their young children including under developed primary teeth and early childhood caries. The effect of in utero exposure to chemotherapy on amelogenesis requires further study.