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Background and Objective: Low electromagnetic fields (LEMF) are produced by instruments which are works with electricity. This study was done to determine the effect of LEMF on fetal death and bone marrow megakaryocytes in NMRI mouse neonates. Materials and Methods: In this experimental study 64 females’ mice with 6-8 old weeks were used. 2 female mice coupled with one male, and positive vaginal plaque was interpreted as the zero day of pregnancy (GD=0). The pregnant mice were randomly categorized into control and experimental groups. The experimental group were exposed to50HZ, 0.5 mT Low electromagnetic fields on 7-11 days of pregnant period (8h/d). The weight of neonate and death fetus were studied after delivery. The live neonates were dissected on 15th day, and 1 ml of bone marrow was extracted from Tibia and vertebral column, by pressing method. The bone marrow cells suspended in 1:1 IMDM in 15cc (FULCON) tubule and cells was counted with neobar lam. The data were tested by t-student test significance was set up at p<0.05. Results: There was significant differences between the mean weight of one day neonate in cases with controls (P<0.05). The mean of dead fetus in experimental group was higher than controls (P<0.05). The mean of megakaryocytes numbers higher than controls, but this differences was not significant. Conclusion: This study showed that the number of megakaryocytes and fetal death were increased by low electromagnetic fields exposure during pregnancy.

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Background and Objective: Electromagnetic waved generated by electronic industries and the increasing use of electrical appliances have led to higher rise in chronic exposure to extremely-low-frequency electromagnetic field (ELF-EMF). This study was done to investigate the effects of low electromagnetic field on mice embryos development. Materials and Methods: In this experimental study, eighty female NMRI mice were super ovulated and coupled with male mated over the night. Next morning the female mice with a vaginal plug were identified as pregnant mice. Animals allocated into 2 groups control group was not exposed to EMF and animals in case group exposed to 50 Hz and amp 1.2 mT EMF the pregnant mice were scarified by cervical dislocation at 24, 72, 81, 96, 110 and 120 hours. Embryos were subsequently obtained from the mice by flashing the fallopian tubule and uterus horn. Data were analyzed using SPSS-13.5, ANOVA and student’s t-tests. Results: The number of 2, 3-4 cells and 5-8 of embryo cells and blastocyst decreased in case group compared to controls, but these reduction were not significant. The number of morula in cases significantly reduced in comparison with control group (P<0.05). The average number of fragmented blastocyst in experimental groups siginficantly increased compared to control group (P<0.05). The number of inner cell mass and trophoectoderm in experimental group significantly reduced in comparison with controls (P<0.05). Conclusion: The exposure of extremely-low electromagnetic field in pregnancy reduces the number of morula, inner cell mass and trophoectoderm.