CT Scan during Pregnancy: Risks and Sid Effects

CT Scan During Pregnancy – Is It Risky?

Medically Reviewed By
Dr. Rima Sonpal (Gynecologist/Obstetrician)
View more Gynecologist/Obstetrician Our Panel of Experts

A CT scan or a CAT scan is the common name for an imaging technique called Computed Axial Tomography scan. It is a procedure that uses a computer to combine several X-ray images to generate a cross-sectional, three-dimensional image of the internal organs of the body. Many women worry about getting a CT scan during pregnancy and the side effects it could pose. If you’re an expectant mother who also has these queries, your questions will be answered in this post. Beyond that, your doctor would be able to explain to you the risks and benefits of a CT scan, if you ever need to have one during your pregnancy.

Is It Safe to Perform CAT Scan During Pregnancy?

CAT scans use a focused beam of X-rays to generate imagery of the body, and this high energy radiation does have the potential to cause harm to a foetus depending on its intensity and exposure range. Ionising radiations such as X-rays are known carcinogens, and their utilisation has been speculated as a potential cause for the increase of cancer in developed countries. When CAT scans are performed during pregnancy, there is also a concern about the carcinogenic and teratogenic effects of the ionising radiation on the growing foetus. The highest risk, however, is for foetuses that are under 15 weeks old and at a radiation threshold greater than 50 mGy.

The risk goes up when the pregnant woman’s uterus comes under the field of scanning, or a scan is performed in a region in the abdominal or pelvic cavity. When radiation shields are applied, scans expose the foetus to a dose of 1 mGY to 3.5 mGy of radiation. In contrast, the radiation exposure of foetuses from the background radiation (from the sun and space) is 0.5 to 1 mGy for a period of 9 months. The typical dosage the foetus is exposed to during a routine CAT scan of the abdomen and pelvis is about 25 mGy. CAT scans of the head or chest expose the foetus to almost no radiation. Advanced scanners with automated exposure control bring down the radiation exposure to 13 mGy.

Is It Safe to Perform CAT Scan During Pregnancy?

Why Are CT Scans Performed?

Pregnant women can sometimes experience non-obstetrical conditions or emergencies that may require the use of CAT scans, some of these conditions, include renal colic, appendicitis, hemorrhagic ovarian cysts, ovarian torsion, pulmonary embolism, and trauma. The utilisation of CAT scans in these instances is highly useful for diagnosis, and sometimes it might be the only tool that can be used to gain a proper insight into the condition. CT scans form a three-dimensional image of the internal organs where doctors can get a clear picture of the exact cause of the problem. However, CT scans are not the only tool used for diagnosis; an MRI scan is also commonly used and is equally effective.

The primary diagnostic tool for pregnant women is the ultrasound, but it cannot always give a detailed view of the organs. When the safer modes of scan such as ultrasound and MRI scans cannot provide a definitive answer, or there is a time constraint, CAT scans are used as the best imaging option. As a rule of thumb, CT scans are not recommended to pregnant women unless the benefits outweigh the risks of exposing the foetus to the radiation.

Risks of Getting a CAT Scan During Pregnancy

Here are some of the common concerns about getting a CAT scan done during pregnancy.

  • A CT scan involves ionising X-ray radiation that is a little higher than the ambient radiation we receive every day. The radiation dose from CT scans can be about 10 mSv, which is about the same radiation the average person receives from the background radiation in 3 years.
  • CT scan during the first trimester of the pregnancy poses the highest risk to the developing foetus, due to the carcinogenic and teratogenic effects of the ionising radiation.
  • An abdominal condition that requires a CAT scan exposes the foetus to high levels of radiation.

Can CAT Scan During Pregnancy Cause Cancer in the Child?

CAT scans use radiation levels that are very low to cause severe damage to the mother or the foetus. Most scans operate within the ranges of 10 to 25 mGy, and the exposure needs to be higher to cause cancer. Teratogenic effects are known to occur when the exposure goes over the threshold of 50 mGy to 100 mGY. A single scan is not of concern; however,  multiple scans raise the risk of radiation exposure. If the exposure goes over 100 mGy to 150 mGy, the risk is serious enough to consider abortion of the foetus.

CAT scans carry certain risks, and it is best to talk to your doctor or care provider about the risks and benefits if you ever need to have one.

Also Read: Are Ultrasound Scans Safe?

Previous article «
Next article »