CT in pregnancy: is it possible, what are the consequences?
A woman carrying a wanted child, very kind to your health and the health of the future baby. But sometimes it happens that a pregnant woman should perform additional examination of the abdomen or CT scan was made before the woman found out about their situation. How dangerous is CT scan during pregnancy if it is appropriate to do and what the consequences might be? In order to answer this question, we need to know more about the principle of operation of the scanner and on the effects of ionizing radiation on the human body.
How does the apparatus for computed tomography?
CT is the modern name of the study. Initially, the technique was called x-ray computed tomography due to the use of ionizing radiation for the scan. Scanner to diagnose is a large device similar to a cube or cylinder with a tunnel and a mobile couch in the center. In the case of the imager are many cathode ray tube, generating x-ray radiation during the examination. During a CT scan is a rotation of the sensor around the patient’s body generates rays passing through the patient’s body. On the reverse side is the reader, trapping the modified rays and converts them into an image.
It is known that the human embryo is very sensitive to negative environmental influences at the stage of laying of all organs and systems. Ionizing radiation used in CT, is able to exert a powerful teratogenic effects while the higher radiosensitivity of the fetus at the earliest stages of development.
Teratogenic effects is the occurrence of various malformations when exposed to radiation in utero.
In the first trimester of pregnancy all the body’s cells are actively dividing – there is a rapid differentiation of tissues, the basis for all critical organs. Passing through the dividing cells, x-rays destroy them by damaging the DNA chain – the main carrier of genetic information. Ionizing intracellular fluid, the radiation contributes to the accumulation of free radicals inside the cell, disrupts the structure of proteins and intracellular amino acids – all this leads to the death or mutation of cells, increasing the likelihood of anomalies.
The negative effect of the CT study, especially the examination of the abdominal cavity of a woman during pregnancy depends on at what period was the study. For example, in the first weeks of fetal development is the formation of the nervous system, so the exposure at this time may cause malformation of the brain – hydrocephalus or microcephaly, which entails a decline in mental abilities in the child. At the stage of laying the cardiovascular system the CT scan of the abdomen may cause valvular defects or heart muscle. By the end of the first trimester, the negative impact of x-ray radiation is reduced, but there is still the likelihood of developing pathologies – at a later date formed the circulatory system and gastro-intestinal tract, the research on this period could contribute to the development of anemia and disorders in the digestive tract of the child after birth.
An important fact to consider is the area where survey was conducted. For example, if you did a head CT, and a pregnant belly was closed by a lead apron, the likelihood of developing pathologies reducing. Do CT of abdomen during pregnancy is highly undesirable.
Possible abnormalities depending on the timing of pregnancy
The data obtained in the study of pregnant women who are in the early stages and exposed to x-ray irradiation of the abdominal cavity in doses exceeding 1 mSv (100 µr / h).
- 1-2 weeks – stop development, the death of the embryo.
- 2-5 weeks – possible termination of pregnancy due to malformations nazaralieva structures that support its viability. Malformations of the heart, liver, thyroid.
- Week 6 – pathology in the nervous system, the hematopoietic system, the sex glands, malformations of the limbs, pituitary gland, thymus.
- 7 weeks – formation disorder of the adrenal glands and abdominal organs in the fetus — the small and large intestine and liver, which leads to failure of the hematopoietic system.
- 8 weeks – cleft palate and upper lip.
- 9 weeks developmental abnormalities of the bronchi.
- 10 weeks – pathology of the dental system.
- 11 weeks – disorders of smell and touch.
- 12 weeks – pathology of the thyroid gland, the consequences of this delayed growth and slow metabolism.
Is it possible to do a CT scan during pregnancy?
Safe level of radiation, which can be applied to the fetus – less than 1 µsv (microsieverts). CT of the abdomen, this figure rises to 11 mSv. Doctors strongly recommend not to do the CT scan during pregnancy. If necessary, the abdominal safe and less informative method is a MRI, in some cases, the abdominal cavity can be examined by ultrasonography.
If a woman got pregnant after a CT scan was performed, you can consult a gynecologist, watching the pregnancy. It is necessary to consider all the conditions – the period of gestation in which the woman was examined, localization of radiation (CT abdominal and chest cavity early on is detrimental to the fetus), the time of exposure to harmful radiation, the data of ultrasonic examination. Doctors in many cases are advised to have an abortion, but you can wait for the results of the first prenatal screening to assess the development in this period many of the defects already visible during the ultrasound examination. Often triggered natural selection is not a viable fetus itself rejected by the body early on.