General considerations Definition In placenta previa, the placenta is implanted in the lower uterine segment and located over the internal os. It constitutes an obstruction of descent of the presenting part. Main cause of obstetrical hemorrhage Incidence 0.24%-1.57% (our country)
General Consideration Definition The separation of the placenta from its site of implantation after 20 weeks of gestation or during the course of delivery Frequency 0.51%0-2.33%(our country) 1%o(other countries) Incidence of fetal death
Definition of AFE AFE is rare obstetric emergenc in which amniotic fluid, fetal cells, hair, or other debris enter the maternal circulation, causing cardiorespiratory collapse
1. Introduction 2. Antigenicity and specificity 3. Requirements for immunogenicity 4. Types of antigens 5. Superantigen ,immunological adjuvants and mitogen
