Embryonic development is an extraordinary process that requires carefully regulated cell proliferation, the formation of distinct cell lineages that adopt unique cellular functions, and ultimately the concerted interaction between cell types to produce tissues complex. These events take place in the mother's uterus after the implantation of the conceptus, this characteristic requires that the conceptus composes additional events, in addition to its own development, related to the control of maternal physiological functions, the growth of the uterus and the provision of nutrients and oxygen through the formation of the placenta; these processes are among the first events to occur during embryogenesis. The following discussion paper will provide a brief description of multiple myeloma. We will then discuss the history of thalidomide, its pathogenesis, usefulness and side effects on embryonic and fetal development. In addition, the factors influencing teratogenicity, the diagnostic process for detecting any defects in the fetus and general recommendations to the patient will be discussed. Multiple myeloma Multiple myeloma is a clonal disease characterized by neoplastic transformation, proliferation and accumulation of plasma cells in the bone marrow. Normally, plasma cells develop from B lymphocytes (also known as B cells), which are a major class of white blood cells, are responsible for producing antibodies that help encounter foreign bodies or infections. In multiple myeloma, however, plasma cells begin to multiply abnormally within the bone marrow and release excessive immunoglobulins into the bones and blood, causing damage to several organs in the body. It is true that the concomitance of multiple myeloma and pregnancy remains relatively rare, g...... middle of paper ......, it is necessary to describe them in detail to the patient and give a prognosis, as far as available medical knowledge allows , regarding pregnancy outcome and postnatal development. To help the patient make a decision about the outcome of the pregnancy, the prognosis should include medically documented risk data. Ethically, termination of pregnancy should not be recommended to the patient, her family and significant others. This option should be discussed, but the final decision whether to continue the pregnancy should be left to the patient, her family, and significant others. Furthermore, I think it is best to refer her to the teratogenic or genetic counselor to help her by providing the patient with as much information as possible and encouraging her to make her own decision whether to continue the pregnancy.