Is a foot X-ray (radiograph) indicated during pregnancy at 26 weeks gestation?

From the Guidelines

A foot X-ray can be performed during pregnancy at 26 weeks, but only if medically necessary, as the radiation exposure to the fetus is minimal, especially with proper shielding, as stated in the 2022 guidelines for the management of urgent obstetric situations in emergency medicine 1. When considering a foot X-ray during pregnancy, it's essential to weigh the benefits of diagnosing a foot injury or condition against the very small potential risk to the fetus. The estimated increase of cancer incidence following fetal exposure to 50 mGy is 1.1 to 3 by 1000, which is minimal, as noted in the 2022 study 1. Some key points to consider:

• Inform the radiologist about the pregnancy so they can take extra precautions, such as using a lead apron to shield the abdomen and pelvis.
• Consider alternative imaging methods like MRI or ultrasound, which don't use ionizing radiation, as recommended in the 2016 Toronto consensus statements for the management of inflammatory bowel disease in pregnancy 1.
• The American College of Radiology (ACR) provides guidance on screening for pregnancy prior to performing a diagnostic test involving ionizing radiation, as outlined in the 2018 acc/hrs/nasci/scai/scct expert consensus document on optimal use of ionizing radiation in cardiovascular imaging 1.
• The benefits of diagnosing a foot injury or condition should outweigh the very small potential risk to the fetus, and if the X-ray is not urgent, it may be prudent to delay it until after delivery. It's crucial to consult with an obstetrician before proceeding with any radiological examination during pregnancy, as they can provide guidance on the best course of action, taking into account the individual patient's situation and the latest evidence, such as the 2022 guidelines 1.

From the Research

Diagnostic Radiography During Pregnancy

• The use of X-rays during pregnancy is a source of anxiety for patients and doctors, but most diagnostic radiation procedures will lead to a fetal absorbed dose of less than 1 mGy for imaging beyond the abdomen/pelvis and less than 10 mGy for direct or nuclear medicine imaging 2.
• Potential adverse outcomes related to radiation exposure during pregnancy include teratogenicity, genetic damage, intrauterine death, and increased risk of malignancy, but the only adverse effect statistically proven at the dose levels associated with diagnostic radiation procedures is a very small increase in childhood malignancy 2.

Foot and Ankle Pathologies During Pregnancy

• Foot and ankle pain and oedema are common complaints among pregnant women, and radiological evaluation may be used to diagnose foot and ankle pathologies, but it could pose a risk to the fetus depending on the gestational age 3.
• The main foot and ankle pathologies encountered in pregnancy are progressive collapsing foot deformity, plantar fasciitis, heel pain, oedema, and fractures, and treatment plans range from symptomatic conservative to surgical options 3.

Guidelines for Diagnostic Imaging During Pregnancy

• Ultrasonography and magnetic resonance imaging are not associated with risk and are the imaging techniques of choice for the pregnant patient, but they should be used prudently and only when use is expected to answer a relevant clinical question or otherwise provide medical benefit to the patient 4, 5.
• With few exceptions, radiation exposure through radiography, computed tomography scan, or nuclear medicine imaging techniques is at a dose much lower than the exposure associated with fetal harm, and if these techniques are necessary, they should not be withheld from a pregnant patient 4, 5.

Foot X-ray During Pregnancy at 26 Weeks Gestation

• There is no specific evidence to suggest that a foot X-ray is contraindicated during pregnancy at 26 weeks gestation, but diagnostic radiography during pregnancy not involving direct abdominal/pelvic high dosage is not associated with any significant adverse events 2.
• The decision to perform a foot X-ray during pregnancy should be based on the available human data and the minimal impact of such procedures, and it should be used prudently and only when use is expected to answer a relevant clinical question or otherwise provide medical benefit to the patient 2, 4, 5.