Effect of Exposure to Ionizing Radiation on Reproductive System

As spermatogonia cells are in continuous cycle and have a long cell cycle. As spermatogonia cells are the most resistant cells of the spermatogonial types. Differentiating cells are distributed at random over the tubules. After irradiation, the repopulation index (RI), which indicates the fraction of repopulated seminiferous tubules, is directly proportional to the number of surviving stem cells (UNSCEAR, 1977). The form of the dose-effect curve is characteristic with an ascending part with total doses below 6 Gy, a plateau at 6–8 Gy, and a descending part with high total dose such as 10 Gy. This humped dose-effect relationship suggests that later doses have less effect than earlier ones, due to progression of the spermatogonial cell population into a more resistant stage (UNSCEAR, 1977). On the other hand, it should be noted that there is a reverse fractionation effect. Dose fractionation decreases the number of surviving As spermatogonia.

After first dose irradiation, stem cells pass to a more sensitive cell cycle stage, assuming cell synchronization. At this point, the surviving As spermatogonia cells are more sensitive than formerly, both to killing and genetic damage (UNSCEAR, 1977). Therefore, a period of sterility is a direct consequence of stem cell killing and dose fractionation determines a detectable delay in the rate of repopulation of germinal epithelium. At 1.8 Gy per fraction, whole A spermatogonia (As and A1-A4) shows an initial decrease—within the first weeks of irradiation— due to A1-A4 reduction, followed by a new level of steady-state growth, since the As spermatogonia remain at near-control levels during the entire 7 weeks of RT (UNSCEAR, 1977). Spermatocytes and spermatid are damaged after receiving a 2–3 Gy and 4–6 Gy dose, respectively.

These doses can determine permanent damage to spermatogenesis (Maltaris et al., 2006). Considering that physiologically spermatocyte and spermatid lifetime is 46 days and that globally the time needed for spermatogenesis is approximately 70 days, the sperm count is dramatically reduced even to azoospermia after that period. A dose of 8 Gy produces azoospermia in nearly all men. Figure 1 depicts radiation effect on spermatogenesis. After RT, seminiferous epithelium repopulation is supported by an increase in As cell proliferation. Return to fertility is a slow process, and it is dependent on the radiation dose (Maltaris et al., 2006). Usually, following dose of 2–3 Gy, recovery occurs in 10–24 months, whereas at doses of 4–6 Gy, it may required up to 10 years (Biedka et al., 2016).

Despite recovery of the sperm count, infertility may occur due to low-quality sperm production or genetic anomalies. After 6 Gy, there is a high risk of permanent sterility. Doses of irradiation >0.35 Gy cause azoospermia, which may be reversible. The time taken for recovery increases with larger doses; complete recovery takes place within 9–18 months following radiation with

Ahmad et al. (2017) reported that Damage to the testes is directly proportional to the dose and time of exposure to artificial radiation or treatment. Evidence exists for sperm count reduction after treatment with low-dose testis irradiation. Moderate- to high-dose irradiation can lead to prolonged drastic decline in sperm count or even azoospermia. The human testes appear to be more sensitive, and the recovery of spermatogenesis after radiotherapy is significantly delayed compared to most other rodents. This delay suggests that during the treatment period, spermatogonial stem cells become arrested at a point of their differentiation; however, the underlying mechanism of the spermatogenesis arrest and subsequent recovery in human is not known. This raises an important question about the posttreatment fertility of the patients and also the consequences of IR exposure on the reproductive health in medical professionals. Ermakova et al. (2020) assessed reproductive parameters in a population exposed to radiation over many generations, two experiments have been performed at an interval of 25 years (in 1984 and 2009). The observed intensification of reproductive processes is evidence for an adaptive response of the population to chronic low-intensity irradiation that is aimed to counterbalance high embryonic and postnatal mortality. However, the results of inbred crossing confirm that heritable genetic damage caused by exposure to environmental HNRs is detected in the population even after 100 generations. Alexander et al. (2018) noted that exposure to low-dose ionizing radiation can have positive impacts on biological performance—a concept known as hormesis. Although radiation hormesis is well-documented, the predominant focus has been medical. In comparison, little research has examined potential effects of early life radiation stress on organismal investment in life history traits that closely influence evolutionary fitness (eg, patterns of growth, survival, and reproduction). Evaluating the fitness consequences of radiation stress is important, given that low-level radiation pollution from anthropogenic sources is considered a major threat to natural ecosystems. Using the cricket (Acheta domesticus), we tested a wide range of doses to assess whether a single juvenile exposure to radiation could induce hormetic benefits on lifetime fitness measures. Consistent with hormesis, we found that low-dose juvenile radiation positively impacted female fecundity, offspring size, and offspring performance. Remarkably, even a single low dose of radiation in early juvenile development can elicit a range of positive fitness effects emerging over the life span and even into the next generation.

Turid et al. (2011) reported that ionizing radiation requires knowledge about the responses of individuals and populations to chronic exposures, including situations when exposure levels change over time. The investigated processes such as recovery and the adaptive response with respect to reproduction endpoints in the earthworm Eisenia fetida exposed to (60) Co γ-radiation. Furthermore, a crossed experiment was performed to investigate the influence of F0 parental and F1 embryonic irradiation history on the response of irradiated or non-irradiated F1 offspring. Recovery: The sterility induced by sub-chronic exposure at 17 m Gy/h (accumulated dose: 25 Gy) was temporary, and 8 weeks after irradiation the worms had regained their reproductive capacity (number of viable offspring produced per adult per week). Adaptive response: Adult worms were continuously exposed at a low priming dose rate of 0.14 mGy/h for 12 weeks (accumulated dose: 0.24 Gy), followed by 14 weeks exposure at a challenge dose rate of 11 mGy/h. The results suggest a lack of adaptive response, since there were no significant differences in the effects on reproduction capacity between the primed and the unprimed groups after challenge doses ranging from 7.6 to 27 Gy. Crossed experiment: The effects of exposure at 11 mGy/h for 21 weeks on growth, sexual maturation and reproduction of offspring, derived either from parent worms and cocoons both exposed at 11 mGy/h, or from non-irradiated parents and cocoons (total accumulated dose 44 and 38 Gy, respectively) were compared. There were no significant differences between the two exposed offspring groups for any of the endpoints. The reproduction capacity was very low for both groups compared to the controls, but the reproduction seemed to be maintained at the reduced level, which could indicate acclimatization or stabilization. Finally, parental and embryonic exposures at 11 mGy/h did not affect reproduction in the F1 offspring as adults.

The research conducted by Kavindra et al. (2018) found that male infertility has to be attributed to an array of environmental, health and lifestyle factors. Male infertility is likely to be affected by the intense exposure to heat and extreme exposure to pesticides, radiations, radioactivity and other hazardous substances. Population was surrounded by several types of ionizing and non-ionizing radiations and both have recognized causative effects on spermatogenesis. Radiation deriving from cell phones, laptops, Wi-Fi and microwave ovens contributed to the cause infertility pattern of male due to effect of exposure to radiofrequency radiations. From currently available studies it is clear that radiofrequency electromagnetic fields (RF-EMF) have deleterious effects on sperm parameters (like sperm count, morphology, motility), affects the role of kinases in cellular metabolism and the endocrine system, and produces genotoxicity, genomic instability and oxidative stress. The study concludes that the RF-EMF may induce oxidative stress with an increased level of reactive oxygen species, which may lead to infertility. This has been concluded based on available evidences from in vitro and in vivo studies suggesting that RF-EMF exposure negatively affects sperm quality (Samaila et al., 2023 and Samaila et al., 2023). In a similar investigation done by James et al. (2023) highlighted that for procedures utilizing ionizing radiation for which the conceptus is not included in the primary radiation beam, Typical doses are well below the threshold for causing tissue reactions and the risk of induction of childhood cancer is low as well, while for procedures that include the conceptus in the primary radiation field, longer fluoroscopic interventional procedures or Multiphase/multiple exposures potentially could exceed thresholds for tissue reactions and the risk of cancer Induction. Gonadal Shielding is no longer considered best practice. Emerging technologies such as whole-body DWI/MRI, dual-energy CT and Ultralow dose studies are gaining importance for overall dose reduction strategies. The ALARA principle, considering potential benefits and risks should be followed with respect to the use of Ionizing radiation. Nevertheless, as Wieseler et al. (2010) state, “no examination should be withheld when an important Clinical diagnosis is under consideration.” Best practices require updates on current available technologies and guidelines. Shayenthiran et al. (2017) Used mouse and rat models to examined prenatal ionizing radiation effects in postnatal development of the offspring. long-term effects of prenatal radiation exposure are important factors to consider when assessing radiation risk, since these effects are of relevance even in the low-dose range. Meng et al. (2019) provide the first evidence that prenatal exposure to a continuous low-level dose of radiation significantly reduces gestational length and increases the probabilities of prematurity and low birth weight.

Hyeyeun et al. (2015) studied association between maternal occupational exposure to IR and birth defects. 38,009 mothers who participated in the National Birth Defects Prevention Study and delivered between 1997 and 2009 were involved in the study. 39 birth defects were assessed, observing that maternal occupations with potential exposure to IR were associated with a significantly increased risk for 4 birth defects and a significantly protected risk for 1 birth defect. Roger and McClellan. (2022) carried out a cohort study and observed small dose-related increase in cancer, chronic cardiovascular and respiratory diseases while using thousands of mice irradiated with high doses of radiation indicated a small heritable effect. Also, some dose-related health effects were observed in individuals exposed in utero. Chi et al. (2021) showed that the radiation could alter the expression of gene cluster related to DNA damage responses through the control of MYC, leading to transgenerational reproductive impairments. Soma et al. (2021) examined the influence of radiation on female fertility and fertility preservation. The findings demonstrated that radiation exposure can result in impairment of tissue integrity and sometimes, leading to organs dysfunction, the impact of radiations on organs depends on site of irradiation, patient age and total radiation dose. Female patients who are treated with radiation have an increased rate of uterine dysfunction, ovaries dysfunction, impaired fertility, incidence of pregnancy complications, premature birth and miscarriage. Pre-pubertal uterus is more vulnerable to the effect of radiation, compared with the pubertal uterus due to arising ovarian estrogen production and uterus enlarges. To reduce the effects of radiations on female reproductive organ, fertility preservation procedures such as ovarian transposition, reproductive gland protection and oocyte cryopreservation should be carried out before and/or during radiotherapy. Roberto et al. (2018) overviewed various effects of radiotherapy on female reproductive function and current fertility preservation. The results showed that ionizing radiations have a gonadotoxic action with long-term effects that include ovarian insufficiency, pubertal arrest and subsequent infertility. Cranial irradiation may lead to disruption of the hypothalamic-pituitary-gonadal axis, with consequent dysregulation of the normal hormonal secretion. The uterus might be damaged by radiotherapy, as well. In fact, exposure to radiation during childhood leads to altered uterine vascularization, decreased uterine volume and elasticity, myometrial fibrosis and necrosis, endometrial atrophy and insufficiency. As radiations have a relevant impact on reproductive potential, fertility preservation procedures should be carried out before and/or during anticancer treatments. Fertility preservation strategies have been employed for some years now and have recently been diversified due to advances in reproductive biology.

Kausik et al. (2017) identified many factors that can affect reproductive health of men and women, and irradiation that caused a profound effect on reproductive functions. The findings  indicated that there’s large number of experimental data available on the adverse effects of radiation on reproductive health, which included infertility, sexual dysfunction, miscarriage, spontaneous abortion, birth defects, and perinatal mortality due to exposure to ionizing radiation. Aurora et al. (2012) reviewed the current knowledge of radiobiology and reproduction, paying attention to mammalian females. The results showed that radio-induced DNA damage occurs in germ cells during spermatogenesis and produced chromosomal reorganizations associated with meiosis malfunction, abortions, as well as hereditary effect.

Kausik and Rajani, (2011) discussed radiation dose and risk, the reproductive consequences of exposure to radiation, some historical perspectives and new details on involvement of novel regulatory inputs in reproductive functions as potential targets to preserve fertility after radiation exposure. The findings reported that Radiation exposures affected the development of sperm and eggs or potentially exposed the fetus/embryo to radiation that led to birth defects and genetic diseases. Reproduction in both the male and female was controlled by a complex series of hormonal interactions that begin in the hypothalamus–pituitary–gonadal (HPG) axis located at the base of the brain. The testicle is one of the most radiosensitive organs and the damage depends on the radiation dose. In general, the degree of testicular damage to the germinal epithelium and Leydig cell is dependent on the radiation dose and the age and puberty stage of boys. For women exposed to radiation during diagnostic procedures or when undergoing chemotherapy and radioactive therapy in the treatment of cancer and other illnesses, the major side effects of these treatments are ovarian failure and infertility. Ovarian toxicity is an important and common long-term side effect of curative chemotherapy and radiotherapy.

Michal et al. (2019) systematized the current state of knowledge concerning the effect of IR on the female reproductive system. A considerable part of studies concerning the effect of IR on female germ cells have been conducted on animals. Their extrapolation to humans is hindered because in animal studies high acute exposures are applied, which do not reflect human environmental exposures characterized by chronic low dose exposure. Studies on animals provide a heterogenous image, which hinders the formulation of unequivocal conclusions and indicates that radiosensitivity depends, i.a. on IR dose, stage of development of oocytes, the applied marker of the effects of IR, or on the species. LD50 of human oocytes is estimated to be below 2 Gy. The effect of IR depends, i.a. on the dose fractionation and the age (older women are more radiosensitive). In females, the effective sterilizing dose is: at birth 20.3 Gy, at 10 years 18.4 Gy, at 20 years 16.5 Gy, whereas at 30 years 14.3 Gy, which is associated with the available pool of ovarian follicles. Within the range of low doses received as a result of environmental exposure to IR, there is no evidence for the occurrence of either adverse pregnancy outcomes, nor fertility disorders in females. These effects may be related to the cancer radiotherapy, or exposure to high IR doses during nuclear accidents.

Artur et al. (2019) investigated the state of knowledge concerning the effect of IR on the male reproductive system. The results showed that there is no basis for the application of the hypothesis of hormesis in the area of male reproductive health. Regarding the impact of IR on spermatogenesis, spermatogonia was less susceptible to the occurrence of DNA damage after exposition to IR, but are characterized by slower DNA repair compared to somatic cells. Damage to the genes after exposure to IR was possible at each stage of spermatogenesis; however, haploidal spermatids display the highest radiosensitivity in this respect. The genetic risk of the cells differentiating during spermatogenesis was limited to one cycle of spermatogenesis, whereas the genetic instability persisted for the whole period of life, and DNA damage induced by IR may be transmitted to future generations. The minimum dose causing detectable DNA damage was 30 Gy. While exceeding this dose, the number of single-strand DNA breaks increases. Among males exposed to IR, a decrease was observed in sperm motility and in the percentage of morphologically normal spermatozoa as well as in an intensification of vacuolization. The genetic material in the sperm of these males showed higher fragmentation and methylation of genomic DNA. In the context of the epidemiological situation concerning the prevalence of infertility, while assessing the health effects of exposure to IR from artificial, including medical sources, the reproductive risk should be considered.

Embryogenesis and radiation effect

Embryogenesis is a complex process and is divided between pre-implantation, embryo, and fetal period. This process is highly susceptible to various external factors such as teratogenic drugs, alcohol, smoking, radiation, and even the lack of appropriate nutrition. Ionizing radiation way more than non-ionizing has known effects in developing fetus with fatal outcomes. Malignancy is relatively uncommon during pregnancy, with a low incidence of 0.02 to 0.1%. The most common malignancies found are breast, skin including melanoma, gynecological (uterine, cervix, and ovarian), and hematological. Rahul and Orlando (2021) Reported that patients who received surgical monotherapy, survivors who underwent abdominopelvic radiation with or without surgery were more likely to have infants that were premature, low–birth weight, and even associated with perinatal mortality in few cases. Various studies have demonstrated an increased risk of unfavorable pregnancy and neonatal outcomes with prior history of abdominopelvic irradiation, possibly due to radiation-induced uterine damage. Since high-dose uterine irradiation can restrict the pregnant uterus' growth and cause vascular changes that impair uterine blood flow, preterm birth, fetal growth restriction, and stillbirth is common. Signorello et al. observed that infants of patients treated with high-dose radiotherapy (>5 Gy) to the uterus were at a heightened risk of preterm delivery, low birth weight, and small for gestational age when compared with offspring of patients who did not receive radiotherapy. Green et al. observed that the incidence of fetal malposition, early or threatened labor, low birth weight, and prematurity were higher with elevated radiation doses. When compared to radiotherapy, chemotherapy does not appear to have harmful effects on the uterus. Hence it generally has favorable pregnancy outcomes in patients treated only with chemotherapy. Those who conceived ≥ one year after post-chemotherapy without radiation or ≥ two years after chemotherapy with radiation displayed no elevated risks to pregnancy outcomes. Fetal Risks from Ionizing Radiation Significant potential harmful effects of ionizing radiation can be summarized into four main categories: Pregnancy loss (miscarriage, stillbirth) Malformation Disturbances of growth or development Mutagenic and carcinogenic effects While treating cancer in pregnant patients with radiotherapy, the goal is to improve the mother overall survival; however, specific considerations are vital to reduce the fetus's possible adverse implications. Earlier, the norm was to terminate the ongoing pregnancy, regardless of the trimesters. Fortunately, because of the advent of the latest developments of evidence and technology in the last two decades, we have steered away from this blanket policy.

Since the 1990s, various technological and technical advancements in modern radiotherapies, such as 3D-conformal radiotherapy, intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy, have made it possible to give high doses to the tumor while sparing the surrounding healthy tissues or organs in the vicinity, hence improving radiotherapy in terms of effectiveness and tolerability. Furthermore, IMRT techniques using on-board cone-beam computed tomography have evolved to ensure a precise dose delivery. The detrimental principle of all radiation is that it should be "as low as reasonably achievable" (ALARA) as the effects of radiation are linearly cumulative. In practice, even though the fetus is excluded from the direct radiation field, the fetus gets radiation leaking from the accelerator and collimator dispersions. To cut down this radiation, we use lead blocks and shields to achieve ALARA. Childhood malignancy in the context of prenatal diagnostic and assessment X-ray was first reported by Giles et al. in 1956. Their survey of childhood cancers established that the risk increased linearly with the number of films exposed. The relative risk of developing a childhood cancer-associated was significantly higher if the exposure was during the first trimester, about 2.5 times greater than the third trimester. This study became the working model of various radiation-induced teratogenesis studies. A defining study was by Kato et al., where they followed up the survivors of the Hiroshima and Nagasaki atomic bombs. It was the most extensive cohort study of intrauterine radiation exposure; interestingly, only 2 cases had childhood cancer before the 14th birthday out of 1630 children exposed without a single case of leukemia. Broadly, radiation effects are expressed as being either deterministic or stochastic. Deterministic effects have a cause-and-effect relationship such that below a certain threshold, the effect will not occur. However, once the threshold has been crossed, the effect of significance will increase linearly with every next dose. Deterministic effects on a fetus range from congenital malformations, lower intelligence quotient (IQ), mental retardation, microcephaly, various neurobehavioral dysfunctions leading to increased risk of seizures and growth retardation, fetal death, and increased cancer risk. A threshold dose of 0.1Gy has been reported on several occasions. The risks are uncertain between 0.05 Gy to 0.1Gy and deemed negligible when below 0.05Gy. Pathologically, these effects occur when a large number of cells are irradiated during a critical developmental stage of organogenesis. The stochastic effect represents the radiation effects that may occur by chance, such as cancer induction. For this to occur, there is no threshold dose observed, and the risk manifolds in a linear-quadratic manner of the dose. Childhood cancers are primarily the result of the stochastic effect, as seen in the post-Chernobyl disaster with the increased thyroid cancer occurrence. Ionizing radiation induces these effects by causing structural changes at the cellular and molecular levels. Non-ionizing radiation (which is not associated with medical imaging or radiotherapy) causes damage through heat transfer, such as microwave heating. Furthermore, by producing free radicals, ionizing radiation causes cellular damage by interfering with chemical bonds between molecules regulating critical cellular processes and events. This process generally leads to DNA mutation or cell death and sometimes causes damage to essential cellular enzymes. Susceptibility to radiation injury depends on the rate of cellular proliferation and differentiation of exposed tissues. Hence lymphoproliferative tissues with rapid cell turnover are the most susceptible, while nervous tissue with little or no cell turnover is the least affected.

Melony et al., (2005) assessed the reproductive capacity of adult Penaeus (Marsupenaeus) japonicus (Bate) after exposure to ionizing gamma radiation from a cobalt-60 source. Males and females were each exposed to 0, 10 and 20 Gray (Gy) of ionizing radiation (IR) and reciprocally crossed to give nine mating combinations. Fecundity and hatch rate of resulting spawning were used as measures of reproductive capacity. IR significantly (P<0.05) reduced the fecundity of females when treated at 20 Gy compared to 0 and 10 Gy. The mean number of eggs per female for the 0 and 10 Gy crosses was 24,280+/-4680 and 47,000+/-9670 respectively, compared to 11,600+/-6840 for the 20 Gy crosses. Hatch rates from spawning of females crossed with irradiated males were significantly lower (P<0.05) than for females crossed with non-irradiated males. The mean hatch rate of spawning from females crossed with 0 Gy males was 64.02+/-8.85% compared to 20.77+/-5.46% for 10 Gy and 11.95+/-6.13% for 20 Gy male crosses. These results indicate that IR has a negative impact on the reproductive capacity of females at 20 Gy, and males at 10 and 20 Gy. However, IR was not found to be 100% effective at preventing the production of viable offspring using the reported treatment regimes. (C) 2005 Elsevier B.V. All rights reserved. Daniel et al. (2010) determined the effect of treatment for childhood cancer on male fertility. Findings indicated that 6,224 survivors age 15 to 44 years who were not surgically sterile were less likely to sire a pregnancy than siblings (hazard ratio [HR], 0.56; 95% CI, −0.49 to 0.63). Among survivors, the HR of siring a pregnancy was decreased by radiation therapy of more than 7.5 Gy to the testes (HR, 0.12; 95% CI, −0.02 to 0.64), higher cumulative alkylating agent dose (AAD) score or treatment with cyclophosphamide (third tertile HR, 0.42; 95% CI, −0.31 to 0.57).

Effects of radiation exposure on Pregnancy

Exposure to ionizing radiation during pregnancy can have potential effects on the conceptus. The risk of tissue reactions and induction of childhood cancer is low for procedures where the conceptus is not included in the primary radiation beam. However, for procedures that include the conceptus in the primary radiation field, longer fluoroscopic interventional procedures or multiple exposures could approach or exceed thresholds for tissue reactions and increase the risk of cancer induction (James et al.,2023). Pregnant women should be aware of the hazards and risks associated with radiation exposure, and it is important to educate them about dental radiation hazards and the need to reveal their pregnancy status before undergoing dental radiographic procedures (Anand and Sharma, 2022). The effects of radiation exposure on the developing embryo/foetus are still not fully understood, but severe foetal malformations/death, future cancer risk, and impact on cognitive function are among the key health endpoints of concern (Sivasankari et al.,2022). The fetus is most sensitive to radiation between two weeks and 18 weeks of pregnancy, and health problems may include miscarriage, stunted growth, malformations, brain dysfunction, and cancer (Kimberly et al., 2021).

Sundus et al. (2021) investigated Forty pregnant women patients in Al Karama Educational Hospital, Al-Shaheed Dari Al-Fayad Hospital, Baghdad, Iraq, and Al_Hindiya general hospital, Karbala, Iraq. The results showed that most of these patients were exposed to radiation between the second and third weeks of pregnancy. Women exposed to ionizing radiation during pregnancy, where the advice from an official in charge of radiation protection was considered, in addition to the fact that the dose had several limitations, including the type of device used and the procedures used. Therefore, the calculation of the received amount was more accurate if it was calculated for each device correctly individual in some cases. For most cases of radiation exposure, the radiation dose in which the fetus is exposed is less than that to which the mother is exposed, and the stomach of the pregnant mother works in part to protect the fetus from the sources of radiation outside the body. Health problems on the fetus may be from exposure Radiation is dangerous, even at the low radiation doses that May does not cause disease to the mother. Health problems may include miscarriage and stunted growth Malformations, brain dysfunction, and cancer. The fetus is most sensitive to radiation at two weeks of age to 18 weeks of pregnancy, and the fetus is less susceptible to radiation during the stage’s Subsequent pregnancy. Cynthia et al. (2007) examined Forty pregnant women patients from Al Karama Educational Hospital, Al-Shaheed Dari Al-Fayad Hospital, Baghdad, Iraq, and Al_Hindiya general hospital, Karbala, Iraq. The results showed that most of these patients were exposed to radiation between the second and third weeks of pregnancy. Women exposed to ionizing radiation during pregnancy, where the advice from an official in charge of radiation protection was considered, in addition to the fact that the dose had several limitations, including the type of device used and the procedures used. Therefore, the calculation of the received amount was more accurate if it was calculated for each device correctly individual in some cases. For most cases of radiation exposure, the radiation dose in which the fetus is exposed is less than that to which the mother is exposed, and the stomach of the pregnant mother works in part to protect the fetus from the sources of radiation outside the body. Health problems on the fetus may be from exposure Radiation is dangerous, even at the low radiation doses that May does not cause disease to the mother. Health problems may include miscarriage and stunted growth Malformations, brain dysfunction, and cancer. The fetus is most sensitive to radiation at two weeks of age to 18 weeks of pregnancy, and the fetus is less susceptible to radiation during the stage’s Subsequent pregnancy.