Pregnancy can be a crucial juncture in a woman’s life, where doing what is best for the baby takes center stage. The idea of getting an X-ray during pregnancy can invoke a sense of fear about its harmful effect on the fetus.
While it is usually advised to steer clear of getting an X-ray while pregnant, certain medical conditions can make an X-ray inevitable, especially when it can provide crucial information in the diagnosis and management of the condition.
Is X-ray safe during pregnancy?
X-rays are electromagnetic radiation that can pass through the body to produce images of the body’s internal structures including tissues, bones and organs. X-rays are primarily used for diagnostic purposes, which include detecting fractures, infections and tumors. As X-rays pass through the body, they tend to get absorbed in different amounts by different body tissues.
“X-rays are physically ionizing radiations, which means that when high doses of X-ray beams fall on the human cells, it can alter the DNA of the cells, causing genetic mutations. There is also a risk of the fetus developing anomalies,” says Dr Pradeep Srinivasan, director of radiology and fetal medicine, Fortis Hospital, Bannerghatta Road, Bangalore.
However, the effects of X-rays on the fetus depend on the following factors:
- Dose of radiation
- The gestational age of the fetus
- The body part being X-rayed.
X-rays use low-dose radiation
According to the American College of Radiation, no diagnostic X-ray has a radiation dose significant enough to cause adverse effects in the developing embryo or fetus.
“The dose of radiation used in diagnostic X-rays falls below 50 mGy (milligray) and is considered safe for the fetus. When the dose exceeds 100 mGy and especially 150 mGy, it can cause developmental malformations and bone malignancies like leukemia,” says Dr Bandita Sinha, chief consultant, department of obstetrics and gynaecology, Kokilaben Dhirubhai Ambani Hospital, Mumbai.
According to a study published in StatPearls, most of the data on the impact of high-level radiation exposure on the fetus is obtained from observations of people who suffered from Japan’s Hiroshima bombing and the Chernobyl nuclear power plant disaster.
Based on the observations, the consequences of high radiation exposure can be categorized into four broad groups, including pregnancy loss, malformation, developmental delay or retardation and carcinogenesis.
Shedding light on the radiation exposure through security scanners in airports and metros, Dr Pradeep says the low dose does not harm the fetus.
Is an X-ray of the pelvis unsafe?
Certain body parts are considered more vulnerable than others, due to their proximity to the reproductive organs.
“It is advisable to avoid X-rays on the pelvic region during the first eight weeks of pregnancy, as the uterus is located within the pelvis, thereby causing direct exposure on the fetus,” says Dr Pradeep.
X-rays of the abdomen, stomach, lower back and kidneys may also expose the fetus to the radiation.
Dr Pradeep opines that while it is advisable to wait until the third month, an X-ray of other body parts like chest, arms, legs and teeth can be done if urgent. “A lead apron is worn over the abdomen to prevent the reproductive organs from getting exposed to the beams.”
He adds that abdominal X-rays are considered safe after the third month of pregnancy.
The stage of pregnancy matters
The fetus’s gestational age at the time of exposure also plays a key role.
“Direct exposure to X-ray radiations during the first two weeks of conception can pose a risk of pregnancy loss,” says Dr Sinha.
Further, she says that between 2 to 8 weeks is the period when the organs form (organogenesis) and there are possibilities of malformations and developmental defects.
“Between 8 to 16 weeks, the neurological development of the fetus can get hampered,” says Dr Sinha.
According to Dr Sinha, X-rays are generally avoided during the first trimester unless necessary. The second trimester is considered relatively safe.
Dr Pradeep says that some women may accidentally get an X-ray without knowing that they are pregnant. “Before doing an X-ray, we inquire about their last period and sexual activity to rule out any possibilities of pregnancy.”
When is an X-ray during pregnancy inevitable?
While abdominal X-rays are to be avoided in the initial weeks of pregnancy, certain situations like trauma and cancers may deem it mandatory.
“If the woman has had a fall and broken her hip, the diagnosis and management of the fracture depends on the X-ray reports. In this situation, the risks and benefits are weighed. If the benefit of getting an X-ray outweighs the risks, a go-ahead is given,” says Dr Sinha.
During the COVID-19 pandemic, chest x-rays have become common among pregnant women infected with the virus. “The only way to find out if lungs were infected by the virus was by getting an X-ray or CT scan,” says Dr Pradeep.
He says that in pregnant women who are beyond 13 weeks of pregnancy, one or two chest X-rays or a CT scan of the chest will not harm their fetus.
“In pregnant women with fetuses less than 13 weeks, the chest X-rays were done by covering the abdomen and pelvis with a lead apron,” adds Dr Pradeep.
Is ultrasound better than X-rays during pregnancy?
Ultrasound is a safe alternative to an X-ray, as it does not pose any harm to the baby.
“Ultrasound uses high-frequency sound waves which bounce off the fetus and go back to create an image of the baby,” says Dr Sinha.
Takeaways
The effect of an X-ray on a fetus depends on the dose of radiation, gestational age and the body part being X-rayed. Unless it is a certain medical condition that makes an X-ray inevitable, it is advisable to wait until the second trimester.
