What is the risk of abdominal X-ray (XR) in pregnancy?

From the Guidelines

Abdominal X-rays during pregnancy are generally considered safe when medically necessary, with the radiation dose typically being less than 0.1-0.3 mGy, well below the threshold of concern for fetal harm (50-100 mGy) 1. The risk of abdominal X-ray in pregnancy is a concern due to the potential effects of ionizing radiation on the developing fetus. However, the benefits of obtaining diagnostic information to guide maternal treatment must be weighed against the minimal but present radiation risk.

Key Considerations

• The gestational age is a consideration, with the first trimester (particularly weeks 2-15) being the period of highest radiosensitivity for the developing fetus 1.
• Alternative imaging modalities such as ultrasound or MRI should be considered first when appropriate, as they do not use ionizing radiation 1.
• If an abdominal X-ray is deemed necessary, proper shielding of the abdomen and pelvis with lead aprons should be used when possible, and the radiation dose should be optimized by using the lowest effective settings 1.
• Patients should be counseled that a single diagnostic X-ray does not significantly increase the risk of birth defects or pregnancy loss, but unnecessary radiation exposure should still be avoided 1.

Radiation Exposure

• The currently accepted cumulative dose of ionizing radiation to the fetus is less than 50 mGy 1.
• The risk of teratogenicity occurs between weeks 2 and 8, and there is an association with intellectual deficit between weeks 8 and 25, but this is considered a lower risk after week 15 1.
• Healthcare providers should follow the ALARA principle (As Low As Reasonably Achievable) to minimize radiation exposure 1.

From the Research

Risk of Abdominal X-ray in Pregnancy

The risk of abdominal X-ray (XR) in pregnancy is a significant concern due to the potential harm it can cause to the fetus.

• Ionizing radiation from X-rays can pose a health risk to fetuses, including growth retardation, organ malformations, neurological effects, fetal death, and cancer 2.
• Approximately 1% of all pregnant women are given abdominal X-rays during the first trimester of pregnancy, and the resulting radiation risks are usually small compared with other risks of pregnancy 3.
• However, the use of conventional imaging methods, including X-rays, is restricted due to the risks to the fetus, and imaging techniques not involving ionizing radiation are preferred 4.
• The patient must be kept informed, and any potential risks to the patient and fetus should be clearly explained 4.

Alternatives to Abdominal X-ray

Alternative imaging methods, such as sonography and MRI, are preferred over X-rays due to the lack of ionizing radiation.

• Sonography remains the first line of imaging, but anatomical visualization can be limited due to displacement of adjacent structures by the gravid uterus 4.
• MRI provides excellent cross-sectional soft-tissue assessment of the abdomen and pelvis, and no study to date has demonstrated significant deleterious effects to the fetus at any gestation 4.
• However, there remains a theoretical risk of tissue heating by radiofrequency pulses, and there must be consideration of benefit versus potential risk for any use of MRI in pregnancy 4.

Minimizing Radiation Exposure

To minimize diagnostic X-ray exposure of the fetus, procedures such as using a limited protocol of sequences and evaluating the radiation dose and risk estimation are discussed 3.

• The use of abdominopelvic CT in pregnant patients with abdominal pain and a negative or inconclusive abdominal MRI is also presented as an option, but with consideration of the radiation risks to the developing fetus 5, 6.