Figure 1

Transverse section through the uterine wall of the pregnant horn and adherent chorion. Specimens were collected at the end of gestation months 1 (a), 3 (b), and 8 (c). Note the increasing thickness of the chorion (C) and the subepithelial connective tissue sheet (*), and the increasing diameter of deep uterine glands within the endometrium (E). MC: myometrium, circular layer; MV: myometrium, vascular layer and ML: myometrium, longitudinal layer.