Placenta previa ( Latin placenta praevia , where prae is “before”, via is “on the way”) are abnormalities of the placenta , in which, attaching itself in the lower segment of the uterus , it covers partially or completely the internal pharynx of the cervix . In this case, the placenta is located below the present part of the fetus, that is, it blocks the fetus from the outside.
There are three options for placenta previa:
- Central or complete placenta previa - the internal pharynx of the uterus is completely blocked by the placenta;
- Lateral or incomplete - the placenta overlaps the internal pharynx of the uterus by 2/3;
- Regional presentation - the placenta overlaps the internal pharynx of the cervix by 1/3.
Often occurs in giving birth repeatedly, in 75-80% of all cases, as well as after abortion or septic diseases due to abortion or childbirth. Therefore, the main hypothesis here is dystrophic changes in the uterine mucosa. Another possible reason is uterine fibroids .
In primiparous presentation, presentation is explained by low motor activity against the background of diseases of the heart, liver or kidneys.