X-rays & CT Scans
Everyday exposureMedical tests & proceduresAlso called · 6 names▾▴
CT scan, CAT scan, diagnostic x-ray, dental x-ray, mammogram, radiology scan
Imaging test
General information · effects depend on amount, timing, and how it is used. About these sources
Research strength: 4 / 5
FDA explains that CT and radiography use ionizing radiation; MotherToBaby says a typical diagnostic X-ray is not expected to expose the fetus to levels linked with pregnancy complications. ACOG also says fetal exposure from radiography and CT is usually below levels associated with fetal harm, and clinically needed imaging should not be withheld. ACOG notes that fetal effects depend on dose and pregnancy stage. MotherToBaby reports that typical diagnostic X-rays have not been linked with higher chances of miscarriage or birth defects. CDC says the imaging team may consider the body area, pregnancy stage, and ways to limit exposure, including changing or delaying a scan when appropriate. Ask your provider about your situation.
Last reviewed: 2026-10-14
Research strength: 4 / 5
MotherToBaby says typical diagnostic X-rays are not expected to increase pregnancy complications, while very high exposure can affect fetal growth or learning. ACOG says effects depend on dose and stage, with the greatest central nervous system sensitivity from exposure at weeks 8 through 15. ACOG also says clinically needed X-rays or CT should not be withheld, and multiple diagnostic X-rays rarely reach levels associated with fetal effects. FDA says imaging should answer a medical question and radiation settings should be optimized to limit exposure. CDC notes that the body area scanned and how far along pregnancy is can affect exposure assessment. Ask your provider about your situation.
Last reviewed: 2026-10-14
Research strength: 4 / 5
MotherToBaby says typical diagnostic X-rays are not expected to increase pregnancy complications. ACOG includes both radiography and CT in its guidance and says medically needed imaging should not be withheld. ACOG says fetal effects depend on dose and pregnancy stage, with the greatest central nervous system sensitivity from exposure at weeks 8 through 15. ACOG says multiple diagnostic X-rays rarely reach doses linked with growth restriction or small head size. CDC and FDA describe dose assessment by body area and medical need, with efforts to limit exposure. Ask your provider about your situation.
Last reviewed: 2026-10-14
X-rays & CT Scans — Breastfeeding
Research strength: 4 / 5
MotherToBaby says diagnostic X-rays produce radiation only while the image is taken and do not leave radioactivity in the body or milk; it reports no expected effect on milk production. ACOG says external diagnostic X-rays do not pose a lactation risk. For CT with intravenous iodinated contrast, ACOG says breastfeeding can continue without interruption, and LactMed says iodinated contrast is poorly transferred to milk and poorly absorbed by infants orally. These conclusions do not apply to every nuclear medicine test: ACOG says radionuclide excretion into milk varies by substance and recommends expert input. Ask your provider about your situation.
Last reviewed: 2026-10-14
Pregnancy
ACOG Committee Opinion 723 says fetal exposure from radiography and CT is usually below levels associated with fetal harm and says clinically needed imaging should not be withheld. It also says fetal effects depend on dose and gestational age. MotherToBaby reports that typical diagnostic X-rays are not expected to increase miscarriage, birth defects, preterm delivery, or low birth weight, while very high doses may affect growth or learning; its fact sheet does not provide a CT-specific fetal-dose table. FDA and CDC emphasize a clinical question, body-area assessment, and dose limitation. A 2026 phantom study compared two X-ray pelvimetry techniques with one low-dose CT protocol; the measured fetal-region dose was lower for the specific CT protocol, but the experiment used a late-pregnancy phantom and did not measure pregnancy outcomes. A 2026 cohort paper was a protocol for studying first-trimester abdominopelvic CT, with no outcome results in the PubMed record.
Breastfeeding
MotherToBaby says external diagnostic X-rays do not leave radiation or radioactivity in the body or milk and do not affect milk production. ACOG says external diagnostic X-rays do not pose a lactation risk and that breastfeeding can continue after iodinated contrast. LactMed's 2022 iodixanol record says intravenous iodinated contrast is poorly excreted into milk and poorly absorbed orally; it reports no relevant published information on infant levels, infant effects, or effects on lactation as of its revision date. ACOG says radionuclide excretion into milk varies by substance and recommends expert input. LactMed's 2026 sodium iodide I 131 record describes a specific radioactive agent with different breastfeeding restrictions; this is not evidence about external X-rays or CT.
X-rays and CT are diagnostic imaging procedures, not medicines. FDA says radiography and CT use ionizing X-ray radiation. Radiography records an image, while CT uses X-rays to produce cross-sectional images. External X-ray equipment produces radiation while the machine is active; MotherToBaby says X-ray procedures do not make the body radioactive. Nuclear medicine studies use radiopharmaceuticals and are a different type of imaging.
What was tested
A 2026 study used a realistic late-pregnancy phantom to measure fetal-region dose distributions for two X-ray pelvimetry methods and one low-dose CT protocol. It measured specific protocols and dose locations, not pregnancy outcomes or every type of X-ray and CT examination. The study's lower measured dose for its tested low-dose CT protocol does not establish a general comparison between all CT and X-ray exams. A separate 2026 first-trimester CT article was a cohort-study protocol, not a report of results.
How to balance limiting radiation exposure with clinically needed imaging during pregnancy
- Source A says
- CDC emphasizes limited exposure and says the clinician may cancel, postpone, or modify an imaging procedure after considering pregnancy and the body area. FDA says imaging should answer a clinical question and dose should be minimized. (CDC: Facts About Radiation in Healthcare for Parents, FDA: Medical X-ray Imaging)
- Source B says
- ACOG says radiography or CT should not be withheld when it is needed for the diagnosis or more readily available than an alternative. (ACOG Committee Opinion 723: Guidelines for Diagnostic Imaging During Pregnancy and Lactation)
- Why they differ
- CDC emphasizes limiting exposure and lists possible case-specific changes. ACOG emphasizes avoiding delay or omission of a needed diagnosis. FDA also says a medically needed exam should proceed when lower or no-radiation alternatives are less appropriate.
- What the evidence shows overall
- The sources share a clinical-need framework: consider the diagnostic question, use an alternative only when it can answer that question appropriately, and limit exposure when imaging is performed. The difference is emphasis, not a reason to change the rating for indicated imaging.
- CDC says the provider may decide to cancel, postpone, or modify imaging to reduce exposure after considering pregnancy status and the clinical question. (CDC)
- FDA says X-ray imaging should answer a medical question or guide treatment, and radiation settings should be optimized to limit exposure. (FDA)
- ACOG says clinically needed radiography or CT should not be withheld and notes that a radiologist can help modify technique to reduce dose. (ACOG)
General research, not specific to pregnancy.
FDA's general guidance also applies outside pregnancy: X-ray imaging should answer a medical question, and dose should be minimized while preserving clinical value.
- FDA says X-ray imaging should be performed only when the referring clinician judges it necessary to answer a clinical question or guide treatment, with efforts to minimize dose. (FDA: Medical X-ray Imaging)
- MotherToBaby: X-raysTeratology serviceSecondary
- ACOG Committee Opinion 723: Guidelines for Diagnostic Imaging During Pregnancy and LactationProfessional societySecondaryIndependent check
- CDC: Facts About Radiation in Healthcare for ParentsUS governmentSecondaryPage dated 2026-07-16Independent check
- FDA: Medical X-ray ImagingUS governmentSecondaryPage dated 2023-08-15Independent check
- LactMed: IodixanolUS governmentSecondaryPage dated 2022-11-30Independent check
- LactMed: Sodium iodide I 131US governmentSecondaryPage dated 2026-09-15Independent check
- Hwang et al. 2026: Abdominopelvic computed tomography during pregnancy and the risk of congenital malformations, study protocolUS governmentPrimary
- Matsunaga et al. 2026: Measured fetal-region dose in X-ray pelvimetry and low-dose computed tomography using a realistic pregnant phantomUS governmentPrimaryIndependent check
Last reviewed 2026-10-14
Independent check 2026-10-14
Not yet clinician-reviewed
Ask your provider about your situation.