Spontaneous dilatation of the cervix of the uterus during the second trimester of pregnancy. The membranes bulge and subsequently rupture, and the fetus is expelled prematurely. It may be caused by forcible dilatation of the cervix during the operation of dilatation and curettage or it may be related to laceration of the cervix during a previous confinement or to previous cervical surgical procedures (e.g. knife cone biopsy).
Subjects: Medicine and Health.