effects of prenatal exposure to extremely low electro-magnetic field on in vivo derived blastocysts of mice

background: indisputable population exposure to widespread electromagnetic fields, has grown concerns over the probable health effects of these fields. objective: the present study was aimed to examine the possible effects of 50 hz extremely low frequency electromagnetic field (elf-emf) exposure on the number and quality of mice blastocysts. materials and methods: in present study, 66 nmri pregnant females divided into two treated and non-treated groups. the treated group exposed to elf-emf (50 hz and 6×10-3 t). subsequently, embryos were collected by flushing the uterine horn and fallopian tubes on the day 3 of gestation. number of trophoectoderm (te) and inner cell mass (icm) cells in blastocysts were determined after differential nuclei staining using a modified method. furthermore, number of all flushed blastocysts calculated in each group. results: there was no significant difference in mean number of blastocysts in treated (6.64±1.34) and none treated (8.22±1.59) groups. in treated group, there were significant decreased in total cell number of blastocysts (p=0.000), number of icm cells (p=0.000), and number of te cells (p=0.001) whereas the ratio of icm/te cells increased (p=0.002). conclusion: the data indicate that elf-emf is able to affect cellular composition of blastocysts, but it can't omit total volume of blastocysts.