“…7,17 Cellular characteristics which have been associated with the effect of progesterone exposure include curling or crowding of squamous cells, destruction of cells, and unusual morphology to cells (navicular or classically called "boat shaped"). 16 This cellular phenomenon caused by progesterone has the potential to affect the cytological interpretation of the cells. Progesterone is thought to promote atrophy of the epithelial cells as well as to decrease the cellular maturation pattern.…”