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1、Placenta PreviaRequirementsMaster the definition, types, clinical manifestations, diagnosis and treatment principles.Be familiar with the pathogenesis, pathophysiology, differential diagnosis, and maternal & fetal outcomes.Understand the etiology and prevention. Case A 34 yr-old pregnancy woman at 3
2、1 weeks is admitted to the obstetric ward. She woke up in the middle of the night in a pool of blood. No pain or uterine contractions . Inspection of the uterus shows the fetus appears transverse lie. Fetal heart tones are regular at 145/min. On inspection her perineum is grossly bloody. Diagnosis?
3、Treatment? General ConsiderationDefinition After 28 weeks gestation, any part of the placenta is implanted in the lower uterine segment, even even partially or totally covered the internal cervical os. partially or totally covered the internal cervical os. Consequently the placenta is Consequently t
4、he placenta is in advance of the presenting part. General Considerationu Incidence 0.24%1.57% (our country) 0.5%0.90% (other countries) Nulliparas: 1/10001/1500 pregnancy Grandmultiparas: 1/20 pregnancyu It is the major reason of hemorrhage in the third trimester pregnancyGeneral ConsiderationuuPlac
5、enta previa statePlacenta previa state（胎盘前置状态）（胎盘前置状态）（胎盘前置状态）（胎盘前置状态） 28 weeks. 35 years 2.multiparity 3.prior cesarean delivery: 5 times 4.smokingCauses 1. Endometrial abnormality 1)Scared or poorly vascularized endometrium in the corpus. 2)Curettage, Delivery, CS and infection of endometrium 2. P
6、lacental abnormality 1)Large placenta (multiple pregnancy) 2)succenturiate lobe （副胎盘）（副胎盘） 3. Delayed development of trophoblast cellEtiologyEtiologySuccenturiate placentaClassificationuComplete placenta previa uPartial placenta previa uMarginal placenta previaComplete PPPartial PPMarginal PPuLow-ly
7、ing placenta（低置胎盘）（低置胎盘） The placenta is implanted in the lower uterine segment such that the placental edge does not reach the internal os, but is in close proximity to it.ClassificationMarginal PPLow-lying PClassificationuPernicious placenta previa（凶险性前置胎盘）（凶险性前置胎盘） previous c-section + placenta p
8、revia placenta accreta: 50%ManifestationuSymptom: Sudden, recurrently painless vaginal bleeding in third trimester.CHARACTER of bleeding PainlessManifestationu Unassociated to activity , often occurs during sleep, or sleeps in a pool of blood.u A few nulliparas no bleeding.u Cause of bleeding Mechan
9、ical separation Placentitis Rupture of the venous in the decidua basalisManifestationuThe time of onset of bleeding, the amount, the frequency is related to the types of placenta previa.Types TimeFrequency AmountComplete2832wmoremorePartial3236wmidmidMarginal36wlesslessSign:uAbdominal findings: Uter
10、us is soft, relaxed and no tender. uContraction may be palpated.uFetal heart tones maybe disappear.ManifestationSign:uAnemia or shock (1)repeated bleeding anemia (2)heavy bleeding shockuAbnormal fetal position (1)a high presenting part (2)breech presentation (often)ManifestationDiagnosisuClinical sy
11、mptoms and signsuSonography: the most important diagnoses methodsimplest, precise, safestDiagnosisuMRI: Useful but expensive, check the accretaDiagnosisuSpeculum examinationuVaginal examination: seldom useduRectal examination: useless and dangerousDiagnosisuCheck the placenta and membrane after deli
12、very: The distance from edge of placenta to the rupture of the fetal membranes is less than 7cm.Differential diagnosisu Placental abruptionpainful vaginal bleeding uterus tendernessDifferential diagnosisVascular previaCervix diseasesEffect to mother and fetusuObstetric hemorrhage uPlacenta accreta u
13、Anemia and infection uPremature delivery and perinatal fetus high mortality rateTreatment principlePrinciple:uInhibit contractionuControl bleedinguCorrect anemiauPrevent infectionuPromote fetal lung maturityTreatment methoduExpectant treatment uTermination of pregnancyuEmergent transferExpectant tre
14、atmentIndication: u34weeksuFetal weight 400ml) threaten to mother or fetusu36th weekuMarginal PP with bleeding too much，cant delivery immediatelyu36th week, fetal distress uFetus death or severe malformationTermination of pregnancyuCesarean section Complete and partial placenta previa Huge bleedingu
15、Vaginal delivery Marginal placenta previa Head presentation Progress of delivery satisfactoryTermination of pregnancyuTreat postpartum hemorrhage. 1.Promote uterine contractions. Oxytocin, massage uterus. Uterine B-lynch suture 背带式缝合背带式缝合.Pack uterine cavity with ribbon gauze 宫腔填塞纱条宫腔填塞纱条. 2.Uterine artery ligation. 3.Subtotal hysterectomy次全子宫切除次全子宫切除.Emergent transferupostpartum hemorrhageuPernicious placenta previa（凶险性前置胎（凶险性前置胎盘）盘）uControl contractionsuTransfusion of bloodOxytocin, massage uterineUterine B-lynch SuturePack uterine cavity with ribbon gauzeUterine artery ligation
