Fig. 4From: The fetal-maternal interface of the nine-banded armadillo: endothelial cells of maternal sinus are partially replaced by trophoblastCollagen levels in the endometrial stroma increase during pregnancy. Masson’s trichrome staining. a Non-pregnant. b Early-gestation. c Early-gestation; higher magnification. Note the lack of cytoplasmic blue staining in some stromal cells. d Mid-gestation. GE = glandular epithelium, LE = luminal epithelium, str = endometrial stroma, MBS = maternal blood sinus, Tr = trophoblastBack to article page