A specialized, enlarged, connective tissue cell of the decidua with enlarged nucleus, dense membrane‐bound secretory granules and cytoplasmic accumulation of glycogen and lipid droplets. These cells develop by the transformation of endometrial stromal cells during decidualization. [ http://www.ncbi.nlm.nih.gov/pubmed/30013421 BTO:0002770 Wiki:Decidualization&oldid=908981933 NCIT:C32429 http://www.ncbi.nlm.nih.gov/pubmed/30429548 Wiki:Decidual_cells&oldid=937509751 ]