Fluorography in pregnancy: effects on the fetus, consequences than dangerous
Around the question - you can do fluorography during pregnancy? - the medical environment is quite a lot of disputes, because with fluorography, which is an X-ray method of visual examination of the lungs, the body is exposed to ionizing radiation. And most of all, this radiation can damage the embryonic stem cells.
Is fluorography essential for pregnancy?
Nevertheless, in our realities there is one more question: is fluorography mandatory in pregnancy? And the answer is the following: in the list of tests and medical examinations, which require in female consultations when taking pregnant women for obstetrics, chest X-ray does not appear. At least, this is not in the official document - Order of the Ministry of Health of Ukraine No. 417 "On the organization of outpatient obstetric-gynecological assistance in Ukraine" of July 15, 2011.
But problems are still possible. At the primary address of the pregnant woman to the women's consultation they can suggest filling out the Form of Information, where consent is given, we quote in translation: "to pass all the methods of examination offered to me in time (laboratory, physical, ultrasound), if necessary, be examined by other specialists (if there are indications) ".
And further: "I confirm that the possible harm from medical interventions is less important to me than the circumstances that prompted me to agree to them, and therefore I voluntarily and knowingly give my consent to the application of the proposed set of medical interventions to me, as well as other medical interventions that will complement and provide an adequate treatment process. Nevertheless, below I indicate medical interventions that I refuse to do under any circumstances, except in the case of an immediate threat to my life and the life of my child or reconciliation with me. " And there must be a medical intervention, from which the woman flatly refuses.
However, a woman should bring an obstetrician-gynecologist an extract from her outpatient card, which is given by the district therapist or family doctor. It contains item 8 - Tuberculosis in the family, with subparagraph 8.1 - the result of a fluorographic / radiographic examination (indicating the date of its passage). If there is no result, then there is an occasion to conduct fluorography during pregnancy ...
But for detection of tuberculosis - and every doctor should know it - blood is shed and its enzyme-linked immunosorbent assay (ELISA) and PCR analysis are done; A sample of the patient's sputum is also examined under a microscope using the Tsily-Nielsen method, which allows detecting mycobacterium tuberculosis (Mycobacterium tuberculosis or Koch sticks).
In addition, it is useful for pregnant women to know (and do not forget the doctors) that the hormonal changes in the period of gestation are reflected in the upper respiratory tract: swelling and hyperemia of the mucosa, increased secretion of mucus from the bronchial tubes, and as the gestation period increases The chest becomes wider, and the diaphragm rises a few centimeters up.
Fluorography in the planning of pregnancy
To make sure beforehand that there are no problems with the lung, in particular, to exclude tuberculosis, obstetrician-gynecologists are advised to undergo digital fluorography when planning pregnancy. With her, as with normal fluorography, no preparation is required.
If there is no digital fluorograph in the medical institutions of your locality, radiologists recommend taking a chest X-ray. Firstly, the X-ray image of the lung tissue is much more clearly visible, and it is easier for the doctor to make a diagnosis. Secondly, a single effective equivalent dose of ionizing radiation in X-rays is significantly lower than in conventional fluorography - 0.1-0.3 mSv.
A conception is better to plan at least three months after passing a woman's fluorography.
Technique of the fluorography in pregnancy
Other experts argue that the technique of conducting fluorography in pregnancy involves the use of a special shielding apron, which serves as the protection of the uterus and organs of the abdominal cavity and small pelvis.
There is also the opinion of doctors that any examination using X-rays during pregnancy can be carried out solely for life reasons.
And vital indications during pregnancy are situations that threaten the life of the future mother, which arise: with anaphylactic reactions; pneumo- and hydrothorax (ingress of air or exudate into the pleural cavity) and developing lung atelectasis; embolism of the lungs with amniotic fluid; thromboembolism of the lung (in pregnant women prone to deep vein thrombosis); cardiogenic shock (with hypervolemia, venous congestion in the lungs, generalized edema and tissue hypoxia); with peripartal cardiomyopathy (associated with the state of preeclampsia), etc.
But in none of these situations, fluorography is not used. You will ask why? Because fluorography is not a diagnostic method. Western medicine, on the recommendation of WHO, in the mid-1990s brought fluorography out of the scope of the diagnostic examination - due to insufficient information that the doctor gives the image on a fluorographic photograph. In our country and in 13 other European countries, this radiological method is used only to identify the primary (screening) of tuberculosis in the population. But, even after detecting a change in lung tissue in the form of blackouts in the picture, a chest x-ray and corresponding tests are needed to make the diagnosis.
Contraindications to the procedure
It should be borne in mind that during routine chest X-ray (with image retention on film) a single dose of radiation (the so-called effective equivalent dose of ionizing radiation) is 0.7-0.8 mSv (millisieverts), and a year the cumulative dose is not should exceed 1 mSv.
At the same time, some experts believe that fluorography during pregnancy in the early stages is absolutely contraindicated, and it is permissible to conduct it only after the 20th week of gestation. In addition, it should be a digital fluorography during pregnancy, that is, a survey conducted on more modern equipment. With digital fluorography, the image is fixed not to the film, but to an electronic photodiode array, and a single dose of irradiation is 0.05-0.06 mSv.
The harmfulness of fluorography in pregnancy
How does fluorography affect pregnancy? According to studies conducted under the auspices of the American Academy of Family Physicians (AAFP), the teratogenic effect of X-rays accounts for about 2% of all congenital intrauterine defects of the fetus.
However, there is not enough reliable, scientifically proven evidence of the harmful effects of fluorography during pregnancy on the fetus. Especially since the embryo (fetus) is protected in the uterus, and the dose of its irradiation during X-ray examinations is usually lower than the dose received by the pregnant woman. And how to measure it, do not know yet.
Embryo and fetal tissues, as stem cells are in the process of constant division and differentiation, are especially sensitive to X-rays. The consequences of fluorography - according to the concept of the no-threshold action of ionizing radiation - can be quite serious even at low doses. Although, for possible long-term effects, precise doses of radiation are not determined, and even the terms after conception (or gestational age) are approximate.
Pregnancy and radiation dose are the most important factors in predicting the potential impact on the fetus. In the report of the International Commission on Radiological Protection (ICRP) Pregnancy and Medical Radiation, it was noted that the radiation consequences for the embryo state are detected at approximate doses below 50 mSv (0.05 Gy) at all stages of pregnancy. Studies on rodents have shown that there may be malformations and lesions of the central nervous system. It is assumed that a dose of 100 mSv (1 Gy) is likely to kill 50% of embryos, and five times a large dose will result in the death of 100% of human embryos or fetuses at 18 weeks gestation.
Experts from the American National Council for Radiation Protection and Measurement (NCRP) in the report "Radionuclide Exposure of the Embryo / Fetus" note that long-term (stochastic) effects associated with prenatal radiation include fetal death, malformations or an increased risk of oncological diseases in more late age.
Complications after the procedure
Scientific information on the effect of small doses of radiation on a fertilized egg before its implantation in the uterine cavity and in the first 3-4 weeks after conception is extremely limited. For some women who did not know about their pregnancy at the time of the X-ray examination of the lungs, the possible consequences and complications of fluorography during pregnancy for about two weeks are miscarriages. The embryo consists of only a few cells, and damage to even one of them leads to its non-viability. But if the embryo survives, the risk of gene mutations that can lead to the development of congenital anomalies is great. Therefore, doctors recommend in such cases to pass a survey of geneticists, and at the beginning of the second trimester to undergo a fetal examination on ultrasound.
From the third to the ninth week, the frequency of major malformations can increase, so at this time there is an intensive organogenesis - the laying and formation of the fetal organs; possibly slowing growth.
Most researchers agree that during the 16-25 weeks of pregnancy, the dose-dependent threshold of X-ray irradiation, which has a teratogenic effect (especially on brain function), rises to 100-500 mSv (0.1-0.5 Gy), so during this period the central nervous system of the fetus is less sensitive to irradiation .. But this is only a theoretical assumption.
Studies are underway to determine the risk of oncology in children after prenatal exposure to ionizing radiation.