妇产科学精品教学（重庆医科大学）8placental abruption.pptVIP

Placental abruption Dina sun Definition Occurs after 20th weeks, premature separation of the normally situated placenta before delivery of fetus Incidence: in abroad: 1%-2% in our country: 0.46%-2.1%. The fetal mortality is depending on the degree of separation. Placental abruption is a severe complication of late pregnancy. It is also a significant contributor to maternal mortality. peels away from the inner wall of the uterus before delivery — deprive of oxygen and nutrients of the fetus —heavy bleeding in the mother. — mother and baby in jeopardy. Etiology (1)vascular lesion：PIH, especial severe pre-eclampsia, chronic hypertension, chronic renal disease---vascular sclerosis spasm ---Local vascular injury---vascular rupture into decidual basalis ---bleeding, hematoma formation---shears off adjacent denuded vessels, separation of the placenta from the uterine wall. producing further bleeding and enlarging the separated area Etiology uterine venous congestion---sudden rise in uterine venous pressure to intervillous space---congestion or rupture of venous bed---hematoma formation---separation of placenta and uterine wall Etiology (2) Sudden uterine decompression： premature rupture of membrane (especially the preterm PROM) the first fetus is delivered rapidly in twin. amniotic fluid flowed rapidly in polyhydramnios, the uterine cavity’s pressure decreased suddenly, uterus contracts, which cause the separation of the placenta and uterus. Etiology (3)Mechanical factors: trauma or injury to the abdomen short umbilical cord (absolute or relative) In amniocentesis, injure the vessel in the attachment of placenta---hematoma behind the placenta formation---separation of the placenta and uterine wall Predisposing factors Previous placental abruption. Advanced maternal age Multipara Smoking Predisposing factors Abnormal metabolism Predisposing thrombosis. Uterus myoma. drug abuse. Pathological changes  Revealed or external bleeding