1、Placetal PreviaLong Xiaoyu 龙晓宇XuanWu Hospital宣武医院Case 1. 30 G3P2 at 32 weeks gestation, painless vaginal bleeding. Four weeks ago , postcoital vaginal spotting2. BP:110/70mmHg ,abdomen is soft uterus nontender , FHR :140-150bpmCase 1What is most likely diagnosis?What is your next step?Long-term mana
2、gement of this patient?What are the most common causes of Antepartum Hemorrhage ?COMMON CAUSESPlacenta PreviaPlacental AbruptionPreterm laborUNCOMMON CAUSES Uterine rupture Fetal(chorionic ) vessel rupture Cervical or vaginal lacerations Cervical or vaginal lesions, including cancer Congenital bleed
3、ing disorder Unknown ( by exclusion of the above) Placental Previa Understand that placenta previa and placental abruption are major causes of antepartum hemorrhage Know the painless vaginal bleeding is consistent with placenta previaUnderstand that the ultrasound examination is a good method for as
4、sessing placental locationObjectivesDefined as the inferior edge of placenta load at the lower uterine segment, or even reach the internal cervical os after 28 weeks gestation.Incidence rate: Internal：0.24%1.57%； International：0.5%0.9%。Placental Previa“ the placenta overlying the internal os of the
5、cervix”Classification ClassificationComplete(central ) placenta previaPartial placenta previaMarginal placenta previa Low-lying placenta previaWhat are the risk factors for placental Previa?Question ETIOLOGYvIncreased maternal agevUterine factors:Previous CSInstrumentation of the uterine cavity (D a
6、nd C for miscarriages or Induced Abortions)vPlacental factors:MultiparityMultiple gestation Prior placenta previaETIOLOGY Manifestation It characteristically presents with unprovoked and repeated painless vaginal bleeding.Clinical Presentation Manifestation The classification of previa placenta some
7、times determines the occurrence period and the volume of losing blood.Total placenta previaEarly(20-28wks)Large amountSeveral timesBleeding time and volumeCentral placenta previaEarly(20-28wks)Large amountSeveral timesMarginal placenta previa Late(37-40WKS or in labor ) Less bleeding symptom Severe
8、blood losing leads to several shock signs ,such as paleness ,weak and quick pulse and hypotension. Malpresentation maybe exists, and floating presentation could be found during late gestational weeks.Complication of mother and fetus nBleeding at or post partumn Implantation of placentan Anemia and p
9、uerperal infectionn Premature deliveryHow to diagnose the placental Previa?Question Patient History Placenta PreviaPainless bleeding2nd or 3rd trimester, or at termOften following intercourseMay have preterm contractions“Sentinel bleed”Physical Exam Placenta Previan The uterus is usually soft and re
10、laxedn Anomaly of fetal conditionn Fetus is usually alive and welln Per vagina examinationNO digital vaginal exam unless placental location knownAuxiliary examination B-ultrasound examinationl Ultrasound is the easiest, most reliable way to diagnose (95-98+% accuracy)l False positive- ultrasound wit
11、h distended bladder l Transvaginal or transperineal often superior to transabdominal methods MRI Posterior previa High cost Limited availability Laboratory Placenta PreviaHematocrit or complete blood countBlood type and RhCoagulation testsWhile waiting serum clot tube taped to wallDifferentiation di
12、agnosisPlacental abruption vessel PreviaCervical polypusCervical erosionCervical carcinoma Management Expectant delivery aim at achieving amixmum fetal maturity possible while minimizing the risk to both mother and fetus.Management n expectant treatment Indication: Fewer vaginal bleeding Patients co
13、ndition stabilization 36 weeks gestation, fetal weight3434ResuscitateSteroidsUnstableStableResuscitateMildbleedingGestation36 Management Management of placenta previa?Individualized based onGestational ageAmount of bleedingFetal condition and presentationUltrasound examination Placenta previa Expect
14、ant management as long as the bleeding is not excessive. Cesarean delivery at 36 to 37 weeks gestationEach of the following is a risk factor of placenta previa except:A ) Prior cesarean section;B ) Hypertension;C ) Multiple gestation;D ) Prior uterine curettageExercise 1 Each of the following is a t
15、ypical feature of placenta previa except:A ) Painless bleeding;B ) Commonly associated with coagulopathy;C ) First episode of bleeding is usually self-limited;D ) Associated with postcoital spottingExercise 2 A 33-year-old woman at 37 weeks gestation, confirmed by first trimester sonography, present
16、s with moderatedly severe vaginal bleeding. She is noted on sonography to have a placenta previa. Which of the following is the best management for this patient?A ) Induction of labor;B ) Tocolysis of labor;C ) Cesarean delivery;D ) Expectant managementE ) Intrauterine transfusionExercise 3 A 22-yea
17、r-old G1P0 woman at 34 weeks gestation presents with moderate vaginal bleeding and no uterine contractions. Which of the following sequence of examinations is most appropriate ?A ) Speculum examination, ultrasound examination, digital examination;B ) Ultrasound examination, digital examination, spec
18、ulum examination;C ) Digital examination, ultrasound examination, speculum examination;D ) Ultrasound examination, speculum examination, digital examination;Exercise 4 An 18-yeas-old woman is noted to have a marginal placenta previa on an ultrasound examination at 22 weeks gestation. Which of the fo
19、llowing is the most appropriate management?A ) Schedule cesarean delivery at 39 weeks;B ) Schedule an amniocentesis at 36 weeks and deliver by cesarean if the fetal lungs are mature;C ) Schedule an MRI examination at 35 weeks to assess for possible percreta involving the bladder;D ) Reassess placent
20、al position at 32 weeksE ) Recommend termination of pregnancyExercise 5 Understand that placenta previa and placental abruption are major causes of antepartum hemorrhage Know the painless vaginal bleeding is consistent with placenta previaUnderstand that the ultrasound examination is a good method for assessing placental locationObjectives
