Placenta previa：前置胎盘.ppt

If you are a doctornIn the midnight,the pregnant women awakens to find that they have to sleep in a pool of blood How to diagnosis？How to management？YouAntepartum HemorrhageObstetrics&Gynecology Hospital of Fudan UniversityXu HuanRationale(why we care)4-5%of pregnancies complicated by 3rd trimester bleedingImmediate evaluation neededSignificant threat to mother&fetus(consider physiologic increase in uterine blood flow)Consider causes of maternal&fetal deathPriorities in management(triage!)Objectives We will be able to:Describe the approach to the patient with third-trimester bleedingCompare symptoms,physical findings,and diagnostic methods that differentiate bleeding etiologiesDescribe management and delivery options for 3rd trimester bleeding etiologiesDescribe potential maternal and fetal morbidity&mortality Describe management of postpartum hemorrhageApply knowledge in the discussion of clinical case scenariosVaginal Bleeding:Differential diagnosisCommon:Abruption,previa,preterm labor,laborLess common:Uterine rupture,fetal vessel rupture,lacerations/lesions,cervical ectropion,polyps,vasa previa,bleeding disordersUnknownNOT vaginal bleeding!(happens more than you think!)Other EtiologiesCervicitisinfection Cervical erosion Trauma Cervical cancer Foreign body Bloody show/laborPerinatal mortality and morbidityPreviaDecreased mortality from 30%to 1%over last 60 yearsNow emergent cesarean delivery often possibleRisk of preterm deliveryAbruptionPerinatal mortality rate 35%Accounts for 15%of 3rd trimester stillbirthsRisk of preterm deliveryMost common cause of DIC in pregnancyMassive hemorrhage-risk of acute renal failure,Sheehans,etc.Placenta previaDefinition After 28 pregnant weeks placental implantation over the cervical os or in the lower uterine segment It constitutes an obstruction of descent of the presenting part Main cause of obstetrical hemorrhage(20%)Incidence 0.24%-1.57%(our country).Risk factorsPrior cesarean delivery/myomectomyPrior previa(4-8%recurrence risk)Previous abortion Increased parity Multiple pregnancyAdvanced maternal age Abnormal presentation Smoking EtiologyCauses1.Endometrial abnormality1)Scared or poorly vascularized endometrium in the corpus.2)Curettage,Delivery,CS and infection of endometrium2.Placental abnormality Large placenta(multiple pregnancy),succenturiate lobe3.Delayed development of trophoblast ClassificationComplete placenta previaPartrial placenta previaMarginal placenta previaClassificationSymptoms(1)Painless vaginal bleeding(70%)Spontaneous,After coitusThe most characteristic symptomlate pregnancy(after the 28th week)and deliveryCharacteristics:sudden,painless and profuseContractionsNo symptomsRoutine ultrasound findingvThe mean gestational age of first bleed:30 wksv1/3 before 30 weeksSymptoms(2)Anemia or shock repeated bleeding anemia heavy bleeding shockAbnormal fetal position a high presenting part breech presentation(often)Physical FindingsBleeding on speculum examCervical dilationAbnormal position/lieNon-reassuring fetal status If significant bleeding:Tachycardia Postural hypertensionShock Diagnosis(1)History1.Painless hemorrhage2.At late pregnancy or delivery3.History of curettage or CSDiagnosis(2)Signs1.Abdominal findings1)Uterus is soft,relaxed and nontender.2)Contraction may be palpated.3)A high presenting part cant be pressed into the pelvic inlet.(Breech presentation)4)Fetal heart tones maybe disappear(shock or abruption)Diagnosis(3)Speculum examination Rule out local causes of bleeding,such as cervical erosion or polyp or cancer.Limited vaginal examination(seldom used)Palpation of the vaginal fornices to learn if there is an intervening bogginess between the fornix and presenting part.Rectal examination is useless and dangerousLimited vaginal examinationDiagnosis(4)Ultrasoundabdominal 95%accurate to detecttransvaginal(TVUS)will detect almost allconsider what placental location a TVUS may find that was missed on abdominalMRICheck the placenta and membrane after deliveryvremember:no digital exams unless previa RULED OUT!Diagnosis(5)Before 20 weeks gestation,4-6%have some degree of placenta previa on ultrasonic examination 90%of these resolving by the third trimester Only 10%of complete placenta Differential DiagnosisPlacental abruption vagina bleeding with pain,tenderness of uterus.vasa previa In cases of velamentous cord insertion fetal vessels cover cervical osAbnormality of cervix cervical erosion or polyp or cancervasa previaVelamentous placentavasa previaEffectsobstetrical hemorrhagePlacenta accreta,increta,and percreta Anemia and infectionPremature labor or fetal death or fetal distressAbnormally adherent placentation.A.Placenta accreta.B.Placenta increta.C.Placenta percreta ABCManagement(1)Less than 36 wks gestation-expectant management if stable,reassuringRest:keep the bed No vaginal exams(not negotiable)Steroids for lung maturation(32 wks)Controlling the contraction:MgSO4Treatment of anemia Preventing infectionv70%will have recurrent vaginal bleeding