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placenta previa mine.pptx

  1. Placenta Previa Abdul Razick Group 10
  2. Introduction •The Latin word previa means going before, and in this sense, the placenta goes •before the fetus into the birth canal. •Definition- When the placenta is implanted partially or completely over the lower uterine segment (over and adjacent to the internal cervical os) it is called placenta previa •There are multiple types
  3. Etiology • Dropping down theory - The fertilized ovum drops down and is implanted in the lower segment. Poor decidual reaction in the upper uterine segment may be the cause • Persistence of chorionic activity • Defective decidua- results in spreading of the chorionic villi over a wide area in the uterine wall to get nourishment. • Big surface area of the placenta- in twins may encroach onto the lower segment
  4. Types •There are four types of placenta praevia depending upon the degree of extension of placenta to the lower segment. • Type 1 (Low lying) • Type 2 (Marginal) • Type 3 ( Incomplete or partial central ) • Type 4 ( Central or total)
  5. Low lying Placenta Previa The placenta implants in the lower uterine segment but does not reach the cervical os; often this type of placenta previa moves upward as the pregnancy progresses, eliminating bleeding complications later Marginal Placenta Previa The edge of the placenta is at the edge of the internal os; the mother may be able to deliver vaginally.
  6. Partial or Incomplete Placenta Previa The placenta partially covers the cervical os;as the pregnancy progresses, the cervix begins to efface and dilate, then bleeding occurs Central or Total The placenta covers the entire cervical os; usually requires an emergency cesarean section.
  7. •For clinical purpose, the types are graded into • mild degree (Type-I and II anterior) and • major degree (Type-II posterior, III and IV). •Dangerous placenta previa •is the type- II posterior placenta previa because • Placenta is more likely to be compressed, if vaginal delivery is allowed • More chance of cord compression or cord prolapse.
  8. Risk Factors • Multiparity • Increased maternal age (> 35 years) • History of previous cesarean section or any other scar in the uterus • Placental size and abnormality (succenturiate lobes) • Smoking
  9. Signs and Symptoms • The only symptom of placenta previa is vaginal bleeding which is sudden onset, painless, bright red apparently causeless and recurrent • The bleeding is unassociated with pain unless labor starts simultaneously. • In placenta previa, the blood is bright red as the bleeding occurs from the separated uteroplacental sinuses close to the cervical opening and escapes out immediately
  10. Pathological Anatomy • Placenta—The placenta may be large and thin. There is often a tongue- shaped extension from the main placental mass. • Umbilical cord—The cord may be attached to the margin (battledore) or into the membranes (velamentous). • Lower uterine segment—Due to increased vascularity, the lower uterine segment and the cervix becomes soft and more friable
  11. Abdominal Examination • The size of the uterus proportionate to the period of gestation • The uterus feels relaxed, soft and elastic without any localised area of tenderness • Persistence of malpresentation • Head is floating in contrast to the period of gestation. • Fetal heart sound • Stallworthy’s sign
  12. Confirmation Of Diagnosis ● Localisation of placenta
  13. Complications •MATERNAL: During pregnancy • Antepartum hemorrhage with varying degrees of shock is an inevitable complication. • Malpresentation: increased incidence of breech presentation and transverse lie. The lie often becomes unstable. • Premature labor either spontaneous or induced is common • Death due to massive hemorrhage
  14. Complications •During labor • Early rupture of the membranes • Cord prolapse • Slow dilatation of the cervix • Intrapartum hemorrhage • Postpartum hemorrhage • Retained placenta
  15. FETAL COMPLICATIONS mortality from placenta previa are significantly high. • Low birth weight babies • Asphyxia • Intrauterine death • Birth injuries • Congenital malformation
  16. •PREVENTION: • Adequate antenatal care • Antenatal diagnosis • Warning haemorrhage should not be ignored •Expectant treatment- •The aim is to continue pregnancy for fetal maturity without hurting mothers health • Availability of blood for transfusion whenever required • Bed rest • Investigations
  17. • Bleeding occurs at or after 37 weeks of pregnancy • Patient is in labour • Patient is exsanguinated state on admission • Bleeding is continuing and of moderate degree • Baby is dead or known to be congenitally deformed Active management indications-
  18. Definitive Management •Cesarean delivery is done for all women with sonographic evidence of placenta previa where placental edge is within 2 cm from the internal os. It is especially indicated if it is posterior or thick •Vaginal delivery may be considered where placenta edge is clearly 2–3 cm away from the internal cervical os
  19. References •DC DUTTA - textbook of obstetrics 8th edition •Williams textbook of obstetrics 26th edition • 18/ • conditions/placenta-previa/symptoms-causes/syc- 20352768#:~:text=Placenta%20previa%20(pluh% 2DSEN%2D,baby%20and%20to%20remove%20 waste. • -overview
  20. Thank You

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  1. in the decidua capsularis and its subsequent development into capsular placenta which comes in contact with decidua vera of the lower segment can explain the formation of lesser degrees of placenta previa.
  2. (1) Because of the curved birth canal major thickness of the placenta (about 2.5 cm) overlies the sacral promontory, thereby diminishing the anteroposterior diameter of the inlet and prevents engagement of the presenting part. This hinders effective compression of the separated placenta to stop bleeding.
  3. 3-(myomectomy or hysterecotomy) 5-Smoking — causes placental hypertrophy to compensate carbon monoxide induced hypoxemia
  4. As the placental growth slows down in later months and the lower segment progressively dilates, the inelastic placenta is sheared off the wall of the lower segment. This leads to opening up of uteroplacental vessels and leads to an episode of bleeding. As it is a physiological phenomenon which leads to the separation of the placenta, the bleeding is said to be inevitable. However, the separation of the placenta may be provoked by trauma including vaginal examination, coital act, external version or during high rupture of the membranes. The blood is almost always maternal, although fetal blood may escape from the torn villi especially when the placenta is separated during trauma.
  5. Placenta—The placenta may be large and thin.
  6. Slowing of the fetal heart rate on pressing the head down into the pelvis which soon recovers promptly as the pressure is released is suggestive of the presence of low lying placenta especially of posterior type (Stallworthy’s sign). Vulval inspection: Only inspection is to be done to note whether the bleeding is still occurring Vaginal examination must not be done outside the operation theater in the hospital, as it can provoke further separation of placenta with torrential hemorrhage and may be fatal.
  7. Malpresentation: The lie often becomes unstable. Death due to massive hemorrhage during the antepartum, intrapartum or postpartum period
  8. Cord prolapse due to abnormal attachment of the cord Slow dilatation of the cervix due to the attachment of placenta on the lower segment. Intrapartum hemorrhage due to further separation of placenta with dilatation of the cervix.
  9. Low birth weight babies are quite common which may be the effect of preterm labor either spontaneous or induced. Asphyxia is common and it may be the e#ect of — (a) early separation of placenta (b) compression of the placenta or (c) compression of the cord Intrauterine death is more related to severe degree of separation of placenta, with maternal hypovolemia and shock. Deaths are also due to cord accidents Birth injuries are more common due to increased operative interference. Congenital malformation is three times more common in placenta previa. Maternal and fetal morbidity and mortality from placenta previa are significantly high.
  10. Supplementary hematinics A gentle speculum examination after bleeding Use of tocolysis if contractions Rh immunoglobulin Steroid therapy The expectant treatment is carried up to 37 weeks of pregnancy. By this time, the baby becomes sufficiently mature However, preterm delivery may have to be done in conditions, such as: (1) Recurrence of brisk hemorrhage and which is continuing. (2) The fetus is dead. (3) The fetus is found congenitally malformed on investigation.