Abortion Process : Mechanism of Abortion
Mechanism of Abortion
In the early weeks death of the ovum occurs first,followed by its expulsion.In the later weeks,maternal environmental factors are involved leading to expulsion of the fetus which may have signs of life but is too small to survive.
Before 8weeks: The ovum surrounded by the villi with the deciduaal coverings,is expelled out intact.Sometimes the external os fails to dilate so that the entire mass is accommodated in the dilated cervical canal and is called cervical abortion.
8-14weeks: Expulsion of the fetus commonly occurs leaving behind the placenta and the membranes.A part of it may be partially separated with brisk hemorrhage or remains totally attached to the uterine wall.
Beyond 14th week:The process of expulsion is similar to that of a”mini labour”.The fetus is expelled first followed by expulsion of the placenta after a varying interval.