Diagnostic imaging procedures during pregnancy
- Jonathan B Kruskal, MD, PhD
Jonathan B Kruskal, MD, PhD
- Section Editor — Kidney Disease
- Professor of Radiology
- Harvard Medical School
- Section Editors
- Louise Wilkins-Haug, MD, PhD
Louise Wilkins-Haug, MD, PhD
- Section Editor — Prenatal Diagnosis and Genetics
- Professor of Obstetrics, Gynecology, and Reproductive Biology
- Harvard Medical School
- Deborah Levine, MD
Deborah Levine, MD
- Section Editor — Imaging
- Professor of Radiology
- Director of Ob/Gyn Ultrasound
- Department of Radiology
- Beth Israel Deaconess Medical Center
Preconceptional ovarian exposure to diagnostic levels of ionizing radiation has no measurable effect on future pregnancies. Therefore, the ideal time to schedule radiologic procedures in women of reproductive age is during the first 10 days of the menstrual cycle, if possible. At the time of the radiologic examination, all women of childbearing potential should be asked if they could be pregnant . If any doubt exists, the results of a pregnancy test should be obtained before proceeding.
Sometimes diagnostic imaging is necessary during pregnancy, and utilization rates appear to be increasing . Sonographic examination of the uterus and its contents is a common occurrence in pregnant women, but other types of radiological evaluation may also be required. Although the safety of radiation exposure during pregnancy is a common concern, a missed or delayed diagnosis can pose a greater risk to the woman and her pregnancy than any hazard associated with ionizing radiation . In many cases, the perception of fetal risk is higher than the actual risk [4,5]. For the woman herself, the effects of ionizing radiation are the same whether or not she is pregnant, and will not be dealt with in this topic.
Multiple national and international organizations have written guidelines on imaging the pregnant patient. A comprehensive resource including the names of 17 of these organizations and their 33 reports was published in 2011 . The following discussion includes information derived from several of these reports.
Any discussion of the effects of radiation requires background knowledge of radiation nomenclature and dosimetry. The absorbed dose of radiation is the amount of energy deposited per kilogram of tissue and is measured in "rads." One rad is the energy transfer of 100 ergs per gram of any absorbing material. The following relationships apply to diagnostic X-rays in soft tissue:
●1 rad = 0.01 gray (Gy) = 0.01 sievert (Sv) = 1 rem (roentgen-equivalent man)
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- RADIATION BASICS
- EFFECTS OF IONIZING RADIATION ON THE FETUS
- Exposure less than 0.05 Gy (5 rads)
- - Carcinogenesis
- Exposure 0.05 to 0.50 Gy (5 to 50 rads)
- - First 14 days after conception
- - After the first 14 days
- Genetic effects
- FETAL EXPOSURE FROM COMMON PROCEDURES
- ISSUES BY TYPE OF DIAGNOSTIC IMAGING PROCEDURE
- Procedures using ionizing radiation
- - Plain films
- - Fluoroscopy and angiography
- - Intravenous pyelography
- - Computed tomography
- - Dental x-rays
- - Mammography
- Iodinated contrast materials
- - Breastfeeding women
- Nuclear medicine
- - Ventilation-perfusion and helical CT
- - Thyroid scan
- - Positron emission tomography
- - Breastfeeding women
- Magnetic resonance imaging
- - Gadolinium
- Breastfeeding women
- SUMMARY AND RECOMMENDATIONS