How to Cite: Ali, A. R. M., & Abood, A. H. (2022). Histopathological effects of retinol on blastocyst implantation in pregnant rats. International Journal of Health Sciences, 6(S5), 11622–11631. https://doi.org/10.53730/ijhs.v6nS5.11999 International Journal of Health Sciences ISSN 2550-6978 E-ISSN 2550-696X © 2022. Manuscript submitted: 9 April 2022, Manuscript revised: 18 June 2022, Accepted for publication: 27 July 2022 11622 Histopathological effects of retinol on blastocyst implantation in pregnant rats Ashraf Raoof Mohammed Ali Department of Biology, Faculty of Sciences, University of Kufa, Iraq Email: alassadi.ashraf@yahoo.com Ali Hassan Abood Department of Biology, Faculty of Sciences, University of Kufa, Iraq Email: aliha.alkhafaji@uokufa.edu.iq Abstract---Retinol is lipid soluble vitamin widely used during pregnancy as a food supplement.The study has been conducted in Animal House/Faculty of Sciences/University of Kufa between December 2021 and February 2022, fifteen female Albino Rats are used. The present study has been intended to show the histolopathologiacl effects of retinol on blastocyst implantation in female Albino Rats. The females Rats are randomly divided into three main groups, comprising five rats for each group. The control group is given orally injection of physiological normal saline and the second and third group are given orally injection of retinol doses ten, twenty μcg/kg/day respectively for seven days from the first day to the end of experimental allocated for each female.The rats are sacrificed in 7 th (dpc) to study the implantation of embryos in decidual tissues. Retinol doses ten, twenty μcg/kg/day caused macroscopic malformations in embryos of female rats compare to control group. The histopathlogical study of female rats embryos treated with ten, twenty μcg/kg/day of retinol have shown deformations of decidual tissues zonation.In conclusion; retinol caused malformations of embryos in 7 th (dpc) and histopathlogical effects in decidual tissue zonations of blastocyst. Keywords---Rats, Retinol, Implantation, Embryos. Introduction Retinol is the generic term for a variety of fat-soluble substances including retinol, retinyl palmitate and the provitamin A carotenoids such as all-trans-β- caroteneits, its commonly known as the anti-infective vitamin and has an essential role in vision and cellular differentiation, the latter providing a unique core mechanism helping to explain the influence of vitamin A on epithelial