Organ malformations and mental retardation (the sensitivity is high from 2 to 8 weeks, and 8 to 25 weeks after conception, respectively) are the most serious results of fetal exposure to radiation that are observed after birth and probably arise above a threshold dose of 0.1–0.2 Gy. This threshold dose is not generally reached with curative radiotherapy during pregnancy, because most of the tumors are located sufficiently far from the fetus and that precautions have been taken to protect the unborn child against leakage radiation and collimator scatter.
Generally, pregnant women with malignant diseases are advised to delay the radiotherapy until after delivery. If a pregnant patient necessitates radiotherapy the physician should inform the risk of the fetus and the benefits of the mother. Subjects like week of pregnancy, stage of the disease and radiation safety must be discussed in details and the final decision should be taken by the patient. In this review, patients who were exposed to radiation during pregnancy because of radiotherapy and their fetal exposure were discussed.
Key Words: Radiotherapy; Pregnancy; Fetal Exposure.
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