Imaging tests such as X-rays and CT scans have become an integral part of clinical medicine. Many parents are concerned that the “radiation” from these tests may harm the fetus, causing deformities or leukemia later in life. Some pregnant women, knowing that they have been “exposed,” bite the bullet and have an abortion in order to have a healthy baby.
Large doses of ionizing radiation are scary, but what’s scarier is ignorance.
The radiation dose from x-rays is well below the minimum dose that causes fetal problems, and in practice doctors do not usually recommend abortion outright, but rather leave the choice to the pregnant woman with her informed consent.
Many women who are unintentionally pregnant and do not realize it because they think they have irregular menstrual periods, or who have undergone x-ray imaging such as a fluoroscopy or chest x-ray during a medical checkup, are concerned about whether the pregnancy will affect the fetus or whether it should be terminated. The effects of X-rays on the embryo or fetus are as follows:
During the 33 days of pregnancy (counted from the beginning of the last menstrual period) is the “all or nothing” period for external risk factors to affect the embryo or fetus, during this time, the embryo can receive too many X-rays and miscarriage can occur, But this type of very early miscarriage may not be obvious, also known as “biochemical pregnancy”, the woman may only feel that her period is delayed for a few days, if the woman is careful, a urine test will reveal a positive HCG (chorionic gonadotropin); If there is no miscarriage, the risk of other problems with the fetus is not significantly increased, i.e. there is usually no problem.
The sensitive period leading to fetal malformations is from 33 days of gestation to the end of the third month, during which a large number of fetal organs develop intensively, but there are some organs for which the sensitive period for malformations lasts until late in pregnancy. Studies in Japan have found that pregnant women exposed to radiation after the atomic bombings of Hiroshima and Nagasaki are more likely to give birth to babies with microcephaly, mental retardation, or other systemic delays. Fetuses between 4 and 22 weeks of gestation are most susceptible to malformations caused by ionizing radiation. Theoretically, a fetal malformation can occur if a pregnant woman receives a radiation dose of 5 to 15 rad.The radiation dose of common X-ray examination is as follows: Chest X-ray is 0.00007rad for a single time, and it is necessary to take 71429 times to exceed the minimum standard of 5rad; the radiation dose of chest X-ray is about 5-10 times of chest X-ray, and it is necessary to take more than 7000 times to exceed the standard by the most 10 times calculation; Dental X-ray is 0. 0001rad for a single time, and it is necessary to take 50,000 times to exceed the standard; barium enema X-ray The single time of barium enema X-ray examination is 3.986rad, and it takes two times to exceed the standard; the single time of abdominal CT is 2.6rad, and it takes two times to exceed the standard.
X-rays may increase the risk of malignancies (such as childhood leukemia) to which the fetus is susceptible after birth. According to a study by the University of Oxford in the United Kingdom, the risk of developing malignant tumors in early, mid, and late pregnancy was 3.19, 1.29, and 1.30 times higher, respectively, compared with those who were not exposed to radiation. Note that this is a “relative risk” and the incidence of malignant tumors is usually very low, e.g. 1 in 100,000, so a 3-fold relative risk is only an increased incidence of 3 in 100,000, which is actually very low.
Decision-making: Pregnant women need to make their own decisions once they understand the risks of X-rays.
Pregnant women would like their doctors to give them a “yes or no” or “yes or no” answer to the risk of X-rays. In fact, doctors can only assess the risk, and it is generally impossible to answer whether it will be okay, because the risk is calculated theoretically and there is only a yes or no possibility for the individual. Doctors can never promise that the fetus will never be a problem, and the choice is ultimately made by the patient.
Patients should be aware of the following：
1.Even if a pregnant woman is not taking medications, receiving radiation, or having other risk factors, there is still a “background” risk.
For example, the overall risk of spontaneous abortion, fetal malformation, abnormal fetal development, and malignant tumors in children in the general population is 2.86 per 1,000, and most of these cases are very early spontaneous abortions, often manifested as “delayed menstruation” or “irregular menstruation.When a pregnant woman is exposed to a risk factor such as radiation, the total risk of fetal abnormalities is equal to the sum of the additional risk from radiation plus the “background risk. Therefore, this issue must be analyzed objectively, and the cause of fetal problems cannot be attributed to radiation in general.
2.X-rays are not as scary as most people think.
Some studies have shown that after exposure to 0.5 rad, the chance of adverse effects increases by only 0.17 parts per thousand of the original risk, or about 1 in 6,000 fetuses exposed to this dose of x-ray radiation will have an adverse outcome.
3.Whether to terminate a pregnancy?
Doctors may recommend an abortion if the fetus receives a grossly excessive dose of radiation, but this is very rare. The American Congress of Obstetrics and Gynecology guidelines state that exposure to X-rays during pregnancy is not an indication for therapeutic abortion. In other words, doctors will not recommend a therapeutic abortion or induction of labor because a pregnant woman has had an x-ray.