Ionizing Radiation Exposure in NICU.

The authors prospectively studied ionizing radiation exposure in consecutive 107 very low birth weight (VLBW) neonates, admitted to their Level III neonatal intensive care unit (NICU). Number of X-rays, their indications and calculated dose of radiation were documented. Their mean birth weight (+SD) and gestational age (+SD) were 1077 (±219.8) g and 29.7 (+2.57) wk respectively. Extremely low birth weight (ELBW) neonates underwent significantly higher radiographs when compared with VLBW neonates; 7.5(5-13.25) vs. 2(1-6); p < 0.0001. ELBW neonates received 3 times higher dose of radiation, when compared with VLBW neonates; 139.4 µsv (81.6-256.15) vs. 46.6 µsv (14.4-115.7); p < 0.0001. Seven percent of ELBW neonates received >1msv radiation. Lifetime risk associated with high radiation exposure during neonatal period is unknown. Every effort should be taken to reduce number of radiographs. Imaging modalities without radiation exposure such as, point of care ultrasound should be used wherever possible.

Artificially extended photoperiod administered to pre-partum mares via blue light to a single eye: Observations on gestation length, foal birth weight and foal hair coat at birth.

In seasonally breeding animals, photoperiod perception is crucial for timing of important physiological events. In the horse, long day photoperiod influences the onset of ovulation and cyclicity, shedding of the heavier winter coat and the timing of parturition. In this compilation of studies, conducted across three breeding seasons and two countries, the impact of artificially extended day length was investigated on gestation length, foal birth weight and foal hair coat at birth. The light therapy was administered to pre-partum mares via mobile head worn masks which provided short wavelength blue light to a single eye. In Study 1, reductions in gestation lengths were observed following administration of artificially extended day length (124.8 ± 15.11 days) in the final months of pregnancy to a group of Thoroughbred mares compared to controls (P < 0.05; 339.7 ± 9.56 days vs 350.6 ± 9.13). Study 2 revealed that pre-partum exposure to artificially extended day length (104.6 ± 9.89 days) increased foal birth weight compared to controls (47.13 ± 2.93 kg vs 43.51 ± 6.14 kg; P < 0.05) in mares bred early in the year. In Study 3, artificially extended day length (87.53 ± 19.6 days) administered to pre-partum mares affected the coat condition of foals at birth with respect to hair weight (P < 0.0001) and hair length (P < 0.0001) compared to controls (0.34 ± 0.20 µg vs 0.59 ± 0.12 µg and 1.93 ± 0.56 cm vs 2.56 ± 0.32 cm, respectively). Collectively, these studies serve to highlight the influential role of the circa-annual changes in photoperiod length on the pre-partum mare for normal foetal development during the natural breeding season. It also emphasizes the potential that exists to improve breeding efficiency parameters by artificially simulating this important environmental cue in the latter stages of gestation against the backdrop of an economically driven early breeding season.

Pediatric Outcome after Maternal Cancer Diagnosed during Pregnancy.

BACKGROUND: Data on the long-term outcome of children who are exposed to maternal cancer with or without treatment during pregnancy are lacking. METHODS: In this multicenter case-control study, we compared children whose mothers received a diagnosis of cancer during the pregnancy with matched children of women without a cancer diagnosis. We used a health questionnaire and medical files to collect data regarding neonatal and general health. All children were prospectively assessed (by means of a neurologic examination and the Bayley Scales of Infant Development) at 18 months, 36 months, or both. A cardiac assessment was performed at 36 months. RESULTS: A total of 129 children (median age, 22 months; range, 12 to 42) were included in the group whose mother had cancer (prenatal-exposure group) with a matching number in the control group. During pregnancy, 96 children (74.4%) were exposed to chemotherapy (alone or in combination with other treatments), 11 (8.5%) to radiotherapy (alone or in combination), 13 (10.1%) to surgery alone, 2 (1.6%) to other drug treatments, and 14 (10.9%) to no treatment. Birth weight was below the 10th percentile in 28 of 127 children (22.0%) in the prenatal-exposure group and in 19 of 125 children (15.2%) in the control group (P=0.16). There was no significant between-group difference in cognitive development on the basis of the Bayley score (P=0.08) or in subgroup analyses. The gestational age at birth was correlated with the cognitive outcome in the two study groups. Cardiologic evaluation among 47 children at 36 months of age showed normal cardiac findings. CONCLUSIONS: Prenatal exposure to maternal cancer with or without treatment did not impair the cognitive, cardiac, or general development of children in early childhood. Prematurity was correlated with a worse cognitive outcome, but this effect was independent of cancer treatment. (Funded by Research Foundation-Flanders and others; ClinicalTrials.gov number, NCT00330447.).

Safety of MR Imaging at 1.5 T in Fetuses: A Retrospective Case-Control Study of Birth Weights and the Effects of Acoustic Noise.

PURPOSE: To evaluate the effects of exposure to routine magnetic resonance (MR) imaging at 1.5 T during pregnancy on fetal growth and neonatal hearing function in relation to the dose and timing of in utero exposure in a group of newborns at low risk for congenital hearing impairment or deafness. MATERIALS AND METHODS: This retrospective case-control study was approved by the local ethics committee, and written informed consent was waived. Between January 2008 and December 2012, a group of 751 neonates exposed to MR imaging in utero and a group of control subjects comprising 10 042 nonexposed neonates, both groups with no risk factors for hearing impairment at birth, were included. Neonatal hearing screening was performed by means of otoacoustic emission testing and auditory brain stem response according to national guidelines, and the prevalence of hearing impairment in the two groups was compared by using a noninferiority test with Wilson score confidence intervals. The effect of MR exposure on birth weight percentile was examined between the singleton neonates in the exposed group and a randomly chosen subset of 1805 singleton newborns of the nonexposed group by performing an analysis of variance. RESULTS: The rate of hearing impairment or deafness was found to be 0% (0 of 751) in the neonates in the exposed group and was not inferior to that in the nonexposed group (34 of 10 042 [0.34%], P < .05). There was no between-group difference in birth weight percentiles (50.6% for exposed vs 48.4% for nonexposed; P = .22). CONCLUSION: This study showed no adverse effects of exposure to 1.5-T MR imaging in utero on neonatal hearing function or birth weight percentiles.

Telomere length in the two extremes of abnormal fetal growth and the programming effect of maternal arterial hypertension.

We tested the hypothesis that leukocyte telomere length (LTL) is associated with birth weight in both extremes of abnormal fetal growth: small (SGA) and large for gestational age newborns (LGA). Clinical and laboratory variables of the mothers and the neonates were explored; 45 newborns with appropriate weight for gestational age (AGA), 12 SGA and 12 LGA were included. Whether the differences might be explained by variation in OBFC1 (rs9419958) and CTC1 (rs3027234) genes associated with LTL was determined. A significant association between birth weight and LTL was observed; LTL was significantly shorter in LGA newborns (1.01 ± 0.12) compared with SGA (1.73 ± 0.19) p < 0.005, mean ± SE. Maternal (Spearman R = -0.6, p = 0.03) and neonatal LTL (R = -0.25, p = 0.03) were significantly and inversely correlated with maternal history of arterial hypertension in previous gestations. Neonatal LTL was not significantly associated with either rs9419950 or rs3027234, suggesting that the association between neonatal LTL and birth weight is not influenced by genetic variation in genes that modify the interindividual LTL. In conclusion, telomere biology seems to be modulated by abnormal fetal growth; modifications in telomere length might be programmed by an adverse environment in utero.

Residential proximity to electromagnetic field sources and birth weight: Minimizing residual confounding using multiple imputation and propensity score matching.

Studies have suggested that residential exposure to extremely low frequency (50 Hz) electromagnetic fields (ELF-EMF) from high voltage cables, overhead power lines, electricity substations or towers are associated with reduced birth weight and may be associated with adverse birth outcomes or even miscarriages. We previously conducted a study of 140,356 singleton live births between 2004 and 2008 in Northwest England, which suggested that close residential proximity (≤ 50 m) to ELF-EMF sources was associated with reduced average birth weight of 212 g (95%CI: -395 to -29 g) but not with statistically significant increased risks for other adverse perinatal outcomes. However, the cohort was limited by missing data for most potentially confounding variables including maternal smoking during pregnancy, which was only available for a small subgroup, while also residual confounding could not be excluded. This study, using the same cohort, was conducted to minimize the effects of these problems using multiple imputation to address missing data and propensity score matching to minimize residual confounding. Missing data were imputed using multiple imputation using chained equations to generate five datasets. For each dataset 115 exposed women (residing ≤ 50 m from a residential ELF-EMF source) were propensity score matched to 1150 unexposed women. After doubly robust confounder adjustment, close proximity to a residential ELF-EMF source remained associated with a reduction in birth weight of -116 g (95% confidence interval: -224:-7 g). No effect was found for proximity ≤ 100 m compared to women living further away. These results indicate that although the effect size was about half of the effect previously reported, close maternal residential proximity to sources of ELF-EMF remained associated with suboptimal fetal growth.

Ultrasonographic weight estimation in large for gestational age fetuses: a comparison of 17 sonographic formulas and four models algorithms.

OBJECTIVE: To evaluate the accuracy of different formulas and role of fetal parameters (cephalic, abdominal, femur) used for estimation fetal weight (EFW) in large for gestational age (LGA) fetus in diabetic and non-diabetic mothers. METHODS: Seventeen formulas were assessed individually and clustered in four algorithms (X, Y, Z, W) on the basis of fetal biometric parameters using the mean absolute % error, standard deviation (SD), prediction within +/-5%, +/-10%, +/-15% of error and introducing new variable hypotenuse test (HPT) that can sum up precision and accuracy of formulas employed. For predicting fetal macrosomia (BW > or = 4200 g) a receiver-operating characteristic curve was constructed. RESULTS: Warsof2 formula showed the lowest mean % error, SD and HPT (p < 0.01) with overall prediction +/-5, +/-10%, +/-15% of birth weight in 68, 94 and 98%. The formulas that were only based on abdominal measurement (Warsof2, Hadlock1, Campbell) showed the best ability to identify fetal macrosomia. The X algorithm confirming primary role of abdominal circumference for EFW in diabetic mothers. CONCLUSIONS: Accuracy of EFW in LGA fetuses is attributable to the biometric parameters used. Our findings show that the best formulas for EFW are those which only consider the abdominal measurements, especially in diabetic mothers. The new variable that we propose (HPT) confirms this result.

Ionizing radiations in pregnancy and teratogenesis: a review of literature.

The present paper is a review of the data available in the literature concerning the prenatal exposure to radiation evaluating the reported teratogenic effect. We have particularly focused on the fetal effects of maternal ionising radiation exposure, both diagnostic and occupational, particularly in terms of congenital anomalies and birth weight. Ionising radiation represents a possible teratogen for the fetus, but this risk has been found to be dependent on the dosage and the effects correlatable to the gestational age at exposure. Recently, of particularly note is the fact that maternal thyroid exposure to diagnostic radiation has been associated with a slight reduction in the birth weight. Inadvertent exposure from diagnostic procedures in pregnancy doesn't usually increase the natural risk of congenital anomalies but creates a considerable state of maternal anxiety. Diagnostic radiological procedures should be avoided in pregnant women unless the information cannot be obtained by other techniques.

Pregnancy outcome of female survivors of childhood cancer: a report from the Childhood Cancer Survivor Study.

OBJECTIVE: This study was undertaken to determine the effect, if any, of prior treatment with radiation therapy or chemotherapy for cancer diagnosed during childhood or adolescence on pregnancy loss, live births, and birth weight. STUDY DESIGN: We reviewed pregnancy outcome among female participants in the Childhood Cancer Survivor Study (CCSS) who returned a questionnaire. Eligibility for the CCSS included 5-year survivors who were <21 years old at diagnosis and who were diagnosed with an eligible cancer between January 1, 1970, and December 31, 1986, at the 25 participating CCSS institutions. The questionnaire included items regarding attempts to become pregnant, the occurrence of pregnancy, and the outcome of pregnancy (ie, live birth, stillbirth, miscarriage, abortion). Medical records of all members of the cohort were abstracted to obtain chemotherapeutic agents administered, the cumulative dose of drug administered for several drugs of interest, and the doses, anatomic regions, and dates of administration of all radiation therapy. RESULTS: One thousand nine hundred fifteen females reported 4029 pregnancies (63% live births, 1% stillbirths, 15% miscarriages, 17% abortions, 3% unknown or in gestation). There were no significant differences in pregnancy outcome by treatment. A higher, but not statistically significant, risk of miscarriage was present among women whose ovaries were in the radiation therapy field (relative risk [RR] 1.86, P =.14), were near the radiation therapy field (RR 1.64, P =.06), or were shielded (RR 0.90, P =.88). The rate of live birth was not lower for the patients treated with any particular chemotherapeutic agent. The offspring of the patients who received pelvic irradiation were more likely to weigh <2500 g at birth (RR 1.84, P =.03). CONCLUSIONS: This large study did not identify adverse pregnancy outcomes for female survivors treated with most chemotherapeutic agents. The offspring of women who received pelvic irradiation are at risk for low birth weight.

The influence of low doses 131I-induced maternal hypothyroidism on the development of rat embryos.

The aim of our research was to create and verify a model for studying the effects of a low dose of 131I and 131I-induced maternal hypothyroidism on the development of the embryo's thyroid gland and brain. The given dose (150 microCi) corresponds to the absorbed dose of 0.5 Gy. This dose is similar to that dose received by large numbers of the population of the C.I.S. regions polluted by radioactive isotopes of iodine as a result of the Chernobyl accident in 1985. Thirty-five female Wistar rats and their 168 newborn pups were used for observation. The females were divided into a control group and four experimental groups (each distinguished by the time of 131I injection: group I - no less than 12 days before mating; groups II, III and IV - on 5th, 10th and 16th days of gestation, respectively). In all the experimental female groups the incorporate dose of 131I led to hypothyroidism accompanied by a 43% reduction in the thyroxin level and by a nearly 8-fold increase in the TSH level. However, the influence of maternal hypothyroidism on the development of the thyroid gland and brain of embryos depends on the time when 131I took effect. There is a reduction in the weight of the newborns' brain and thyroid gland, total body mass. The hormonal status of the newborns' thyroid gland also changes. The proposed model will allow us to study many aspects of induced changes in the brain and thyroid gland of the embryos which develop under conditions of maternal hypothyroidism resulting from a low dose of 131I, administered at the critical times of development.

Is there an association between preconception paternal x-ray exposure and birth outcome? The ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood.

Diagnostic x-rays are performed commonly on men of reproductive age, yet little is known about the potential effects of these x-rays on the future unborn children of such men. This study examines the possibility that preconception diagnostic x-ray studies of fathers may adversely effect their newborns. The authors used prospectively collected data from the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) for 7,678 birth records for women who gave birth in the County of Avon, England, in 1991-1992. Birth weight, gestational age, and fetal growth of infants whose fathers received diagnostic x-ray examinations likely to deliver significant gonadal doses within one year prior to conception were compared with infants whose fathers did not receive such x-rays. The mean birth weight of babies of exposed fathers was 3,358 g compared with a mean of 3,437 g in the unexposed group (p = 0.055). A similar difference was noted for intrauterine growth, 3,374 g exposed versus 3,437 g unexposed (p = 0.078). The downward trend in birth weight and fetal growth (birth weight adjusted for gestational age) persisted despite control for infants' sex and important parental variables such as age, height, race, education, occupational exposure, parity, and maternal smoking. Because medical x-rays are the largest controllable source of man-made ionizing radiation, more detailed study of the potential effect of paternal x-irradiation on progeny seems justified.

Effect of a 12 Hz and of a 460 Hz pulsed magnetic field on the weight of AKR mice.

AKR mice were exposed to a 6 mT, 12 Hz or 460 Hz pulsed magnetic field (PMF) 30 minutes twice a week. The exposure took place in utero and/or during the life span for four consecutive generations. The adult mice exposed to the 460 Hz PMF only after the birth time were lighter than the controls; for the two frequencies the decrease in weight with the ageing was less pronounced than in the controls. When the exposure took place in utero the exposed new-born mice were heavier than the controls. The difference in weight progressively disappeared when the mice were exposed to the 12 Hz PMF, persisted when the mice were exposed to the 460 Hz PMF.

Differential effects of chronic ingestion of tritiated water on prenatal brain development.

Female rats were given tritiated drinking water (3 microCi/ml) from 30 days before mating up to and throughout pregnancy. At this low dose, the course and the outcome of pregnancy were normal. The differences between newborn body and cerebral weights of the treated rats and those of control animals were on the borderline of significance. In contrast, cerebral DNA and cerebral protein were highly significantly lower. In 30-35% of the treated population the DNA and protein values were more than 2 standard deviations (SD) below the mean values for the control population. Thus the number of the progeny of the mothers exposed to tritiated water that were considered to have "outstandingly low" levels of DNA and protein was 14-17 times greater than in the control group. The irradiated population also had 3-5% of severely affected individuals with cerebral DNA and protein values more than 2 SD below the mean of the experimental population. However, even in this irradiated population, a certain number of individuals did not show the effects of radiation as indicated by DNA and protein values that were not lower than the mean values of the control population. These animals may represent those individuals in which normal (control) populations would have cerebral DNA and protein levels well above the average (by 1 to 2 SD), but here, because of prenatal irradiation, were about average. If so, this lack of effect of irradiation cannot be caused by protection against radiation. However, at present, a differential repair mechanism of protection in those animals (or their mothers) that showed little or no effect of irradiation cannot be excluded.

Evaluation of reproductive function of female rats exposed to radiofrequency fields (27.12 MHz) near a shortwave diathermy device.

In recent years, there has been increased concern regarding effects of operator exposure to the electromagnetic (EM) field associated with shortwave diathermy devices. The present study was designed to investigate the effects, on rats, of repeated exposure to such an EM field. Following repeated exposure for 5 wk, a reduction in fertility occurred as indicated by a reduced number of matings in exposed rats compared to sham-irradiated rats and a reduction in the number of rats that conceived after mating. The data suggest that female operators could experience reduced fertility, if they remained close to the console for prolonged periods. This has particular significant for the physiotherapy profession.

[Characteristics of the descendants of male dogs exposed to chronic combined gamma-irradiation and in the postradiation period]. / Kharakteristika potomstva sobak-samtsov v protsesse khronicheskogo, sochetannogo gamma-oblucheniia i v postradiatsionnyi period.

A study was made of the descendants of 12 male dogs subjected to gamma-irradiation during six years at dose-rates of 0.0034 Gy/day and 0.0017 Gy/day + additional annual exposures to gamma-radiation three times a year each of 0.42 Gy. The observations were made during 3 years after the end of irradiation. It was shown that the descendants reflected the regularities of the disorders revealed in fathers' spermatogenesis. The radiobiological effects were function of dose--rate and cumulative radiation dose. The changes were mainly noted during embryogenesis and manifested by the sterility, mortinatality and the decreased number of puppies in the postreity.

Decreased weight, DNA, RNA and protein content of the brain after neutron irradiation of the 18-day mouse embryo.

Pregnant mice were irradiated with 0.5 Gy fission neutrons on the eighteenth day of their gestation. The average litter size at birth was unchanged but mortality increased 5-6 fold in the first 3 days. The irradiated mice were the same weight as control mice at birth but showed a progressively increasing weight deficiency up to at least 36 days as compared to controls. Brain weight was 37, 45 and 25 per cent less in 2-, 3- and 52-week old irradiated animals, respectively, and the ratio of brain weight to body weight was 25, 27 and 13 per cent less. The concentrations of DNA, RNA and protein (mg/g wet tissue) were the same in irradiated and control mice in both brain and liver at all three ages. Total DNA, RNA and protein contents of whole brain after irradiation were 56-75 per cent of the control levels. No definite decrease was observed in liver. Histological study at 6 hours after irradiation showed nuclear pyknosis in the central nervous system from definite to very severe according to the part examined. It is concluded that damage to the central nervous system of the 18-day mouse foetus after neutron irradiation is mainly due to killing and/or inhibition of the differentiation of neuroblasts.

Neutron irradiation of late mouse embryos (15-19 days) in utero.

Pregnant female C57B1/6 mice were irradiated with a single whole-body dose of 0.5 Gy neutrons. The F1 hybrid embryos were exposed to the neutrons in utero on Day 17 +/- 2 of gestation. 178/439 (40.6%) of the irradiated fetuses and 26/217 (12%) of the control mice died within 2 weeks after birth. In both irradiated and control mice, most deaths (95 and 77%, respectively) occurred within 3 days of birth: most animals in both groups died on Day 2. There was no significant difference in the number of living young born per litter (7.2) between the neutron-irradiated mothers and their unirradiated controls. The irradiated mice weighed significantly less than their controls. On the first day after birth, body weights of mice irradiated in utero averaged only 85% of control weights. Body weights did not reach control levels until 6 months after birth. Several organs were weighed at regular intervals in both irradiated and control mice. Spleens and thymus glands showed no significant differences between the two groups. The livers and kidneys of the irradiated mice weighed slightly less than their controls. The brain weight of 21-day-old neutron-irradiated mice was 30-35% less than control brains. The weight loss of the brain was not only a relative loss, but also an absolute one, based on brain weight/body weight ratios. Histological analysis of the central nervous system showed pycnotic nuclei, inhibition of mitosis in neuroblasts, and cell death in the irradiated brains. The weight reduction of the brain was not due to water loss. Our hypothesis is that the early mortality after birth is related to the killing of the radiation-sensitive neuroblasts. When newborn mice (1-7 days old) were irradiated in vivo with the same neutron dose of 0.5 Gy, neither the reduction in brain weight nor the early mortality was observed. The early deaths of the neutron-irradiated mouse embryos does not appear to be caused by either the hematological or the gastrointestinal radiation syndrome.