Radiation and Pregnancy ©Health Physics Society

Medical X-Ray Exams Radiation exposure that is extra- abdominal will not contribute significant radiation dose to the developing embryo/fetus. Radiation exposure that is extra- abdominal will not contribute significant radiation dose to the developing embryo/fetus. For most extra-abdominal exams, including CT, the radiation dose to the embryo/fetus is less than 0.1 mSv (10 mrem). For most extra-abdominal exams, including CT, the radiation dose to the embryo/fetus is less than 0.1 mSv (10 mrem).

Medical X-Ray Exams Abdomen Exposed Uterus estimated doses 1 – typical values Uterus estimated doses 1 – typical values Upper GI1 mSv (0.1 rem) Upper GI1 mSv (0.1 rem) L-spine4 mSv (0.4 rem) L-spine4 mSv (0.4 rem) Pelvis2 mSv (0.2 rem) Pelvis2 mSv (0.2 rem) Hips/Upper femur3 mSv (0.3 rem) Hips/Upper femur3 mSv (0.3 rem) Abdomen2.5 mSv (0.25 rem) Abdomen2.5 mSv (0.25 rem) Barium enema10 mSv (1.0 rem) Barium enema10 mSv (1.0 rem) IVP6 mSv (0.6 rem) IVP6 mSv (0.6 rem) Abdominal CT30 mSv (3.0 rem) Abdominal CT30 mSv (3.0 rem) 1 Estimated doses can vary significantly, especially when fluoroscopy is used. Adapted from Wagner, et al. Exposure of the pregnant patient to diagnostic radiations

Nuclear Medicine Exams Most of the radiopharmaceuticals used will cross the placental barrier. Most of the radiopharmaceuticals used will cross the placental barrier. In general, the conceptus dose from most diagnostic nuclear medicine exams, other than the radioiodines, will be less than 10 mSv (1 rem). In general, the conceptus dose from most diagnostic nuclear medicine exams, other than the radioiodines, will be less than 10 mSv (1 rem). Adapted from Wagner, et al. Exposure of the pregnant patient to diagnostic radiations

Nuclear Medicine Exams Doses to conceptus from sodium 131 iodide: Doses to conceptus from sodium 131 iodide: Thyroid Thyroid Less than 8 or 9 weeks: thyroid not functional Less than 8 or 9 weeks: thyroid not functional 3-5 months: Sv to conceptus from one MBq administered to mother (960-2,400 rem/mCi) 3-5 months: Sv to conceptus from one MBq administered to mother (960-2,400 rem/mCi) 6-9 months: Sv to conceptus from one MBq administered to mother (1,600-3,100 rem/mCi) 6-9 months: Sv to conceptus from one MBq administered to mother (1,600-3,100 rem/mCi) Whole Body Whole Body Less than 3 months: µSv to conceptus from one MBq administered to mother ( rem/mCi) Less than 3 months: µSv to conceptus from one MBq administered to mother ( rem/mCi) 3-9 months: <55 µSv to conceptus from one MBq administered to mother (<0.2 rem/mCi) 3-9 months: <55 µSv to conceptus from one MBq administered to mother (<0.2 rem/mCi) Adapted from Wagner, et al. Exposure of the pregnant patient to diagnostic radiations

Radiation and Pregnancy Talking Points (if conceptus exposure occurred)

Talking Points Childhood cancer from in utero exposure Childhood cancer from in utero exposure Likelihood of not developing cancer with no radiation exposure is percent. Likelihood of not developing cancer with no radiation exposure is percent. Likelihood of not developing cancer with a 50 mSv (5 rem) dose is percent. Likelihood of not developing cancer with a 50 mSv (5 rem) dose is percent. Conclusion: the chance of developing childhood cancer due to in utero radiation exposure from most medical exams is theoretical. Conclusion: the chance of developing childhood cancer due to in utero radiation exposure from most medical exams is theoretical. Adapted from Wagner, et al. Exposure of the pregnant patient to diagnostic radiations

Talking Points “Specifically, exposure to less than 50 mSv (5 rem) has not been associated with an increase in fetal anomalies or pregnancy loss.” “Specifically, exposure to less than 50 mSv (5 rem) has not been associated with an increase in fetal anomalies or pregnancy loss.” American College of Obstetricians and Gynecologists Policy

Talking Points The general population’s total risk of spontaneous abortion, major malformation, mental retardation, and childhood malignancy for a given pregnancy is just under 30 percent. The general population’s total risk of spontaneous abortion, major malformation, mental retardation, and childhood malignancy for a given pregnancy is just under 30 percent. Statistically, 3 in 10 pregnancies will result in an adverse outcome with no additional radiation exposure. Statistically, 3 in 10 pregnancies will result in an adverse outcome with no additional radiation exposure. A radiation dose of 50 mSv (5 rem) increases this by about 0.17 percent. A radiation dose of 50 mSv (5 rem) increases this by about 0.17 percent. Brent RL. Utilization of developmental basic science principles in the evaluation of reproductive risks from pre- and postconception environmental radiation exposure. Teratology 59:182; 1999.

Talking Points “The risk of abnormality is considered to be negligible at 50 mSv (5 rem) or less when compared to other risks of pregnancy.” “The risk of abnormality is considered to be negligible at 50 mSv (5 rem) or less when compared to other risks of pregnancy.” “The risk of malformation is increased only at levels above 150 mSv (15 rem).” “The risk of malformation is increased only at levels above 150 mSv (15 rem).” Adapted from NCRP Report 54. Medical exposure of pregnant and potentially pregnant women

Talking Points If the radiation dose is received between the second and eighth post-conception weeks, therapeutic abortion based solely on radiation exposure is not advised for doses less than 150 mSv (15 rem). If the radiation dose is received between the second and eighth post-conception weeks, therapeutic abortion based solely on radiation exposure is not advised for doses less than 150 mSv (15 rem). Adapted from Wagner, et al. Exposure of the pregnant patient to diagnostic radiations

Disclaimer In our efforts to create an understandable, easy to read and use program, we have chosen to use the radiation effective dose terms rem or sievert. In some case, for technical precision, the radiation absorbed dose terms rad or gray may be most appropriate. We do not believe that scientific accuracy is lost because of our choice of dose term.