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a name applied to the endometrium during pregnancy, all of which except for the deepest layer is shed after childbirth; called also decidual or deciduous membranes. adj., adj decid´ual.
basal decidua (decidua basa´lis) that portion lying under the implanted ovum and chorion.
capsular decidua (decidua capsula´ris) that portion directly overlying the implanted ovum and chorion, facing the uterine cavity.
menstrual decidua (decidua menstrua´lis) the hyperemic uterine mucosa shed during menstruation.
parietal decidua (decidua parieta´lis) (true decidua) (decidua ve´ra) the decidua exclusive of the area occupied by the implanted ovum and chorion.
the layer of endometrium overlying the implanted chorionic vesicle; it becomes progressively attenuated as the chorionic vesicle enlarges and, by the fourth month, is squeezed against the decidua parietalis and thereafter undergoes rapid regression.
the decidua of the endometrium of the uterus covering the implanted ovum. Also called decidua reflexa.