Effect of oral contraceptives on the ultrastructure of the endometrium.

A low dose oral contraceptive (OC) containing 0.3 mg norgestrel and 0.03 mg ethinyl estradiol was given for conception control in 10 cases, for dysfunction and uterine bleeding (DUB) in 10 cases, for dysmenorrhea in 5 cases, and for endometriosis in 5 cases. Prior to treatment and subsequently the endometrium was studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Post therapeutic TEM indicated marked shrinkage of mitochondria, subnuclear lipid deposition, and loss of nuclear nests in the conception control and dysmenorrhea groups. In the DUB group the epithelial cells and mitochondria became stunted, Golgi-complexes developed, lysosomes appeared, and lipid deposition took place. Significant epithelial and stromal changes also occurred in the endometriosis group with increased of intracellular lipid and hugh enlargement of cell size without abnormal structural alteration. SEM showed stunted isolated cilia, small openings at cell apices, and clear-cut gland openings in the conception control and dysmenorrhea groups. In the DUB group rounded shrunken epithelium with scanty ciliation and prominent microvilli, whereas in the endometriosis group after 6 months total epithelial regression and atrophy was evident. OC therapy may help prevent endometrial carcinoma by inducing regression of subcellular organelles.