Ch 35. OBSTETRICAL HEMORRHAGE

1. Ch 35. OBSTETRICAL HEMORRHAGE 부산백병원 산부인과 R3 서 영 진

2. OBSTETRICS - “bloody business” - transfusion : reduce the maternal mortality rate & death from hemorrhage - but, hemorrhage is leading cause of maternal mortality and ICU care in obstetrics hospital - so, prompt administration of blood are absolute requirements for acceptable obstetrical care

3. - hemorrhage · antepartum: placental previa, placetal abruption · postpatrum: uterine atony, genital tract laceration

4. causes of hemorrhage number(%) Placental abruption 141(19) Laceration/uterine rupture 125(16) Uterine atony 115(15) Coagulopathies 108(14) Placental previa 50(7) Uterine bleeding 47(6) Placenta accreta/increta/percreta 44(6) Retained placenta 32(4)

5. Incidence and predisposing conditions - the incidence of obstetrical hemorrhage cannot be determined precisely - Combs and colleagues(1991) : Hct drop of 10 vol. % → 3.9% in vaginal delivery 6~8% in cesarean delivery

7. ANTEPARTUM HEMORRHAGE • bloody show - in active labor the consequence of effacement & dilatation of cervix tearing of small veins • Bleeding from a site above the cervix before delivery - placenta previa placental abruption vasa previa → Delivery should be considered in any woman at term with unexplained vaginal bleeding

8. < PLACENTAL ABRUPTION > • Definition - ‘ the separation of the placenta from its site of implantation before delivery ‘ - abruptio placentae : rending asunder of the placenta - total vs. partial external vs. concealed : concealed - much greater maternal and fetal hazard - diagnosis typically is made later

10. Frequency and significance - average about 1 in 200 deliveries - so extensive as to kill the fetus : 1 in 420 deliveries (1956~1967) - high-parity woman ↓ & prenatal care ↑ & emergency transportation improved : the frequency of abruption causing fetal death dropped to about 1 in 830 deliveries (1974~1989)

11. Perinatal morbidity and mortality - as stillbirths from other causes have decreased, those from placental abruption have become especially prominent - but, perinatal mortality was 25-fold higher with placental abruption - if the infant does survive, there may be adverse sequelae : neurological deficits (15%), cerebral palsy (20%)

12. Ethiology risk factor relative risk increased age and parity 1.3~1.5 preeclampsia 2.1~4.0 chronic hypertension 1.8~3.0 PtPROM 2.4~4.9 mutifetal gestation 2.1 hydramnios 2.0 smoking 1.4~1.9 thrombophilias 3~7 cocaine use NA prior abruption 10~25 uterine leiomyoma NA

13. - maternal age

14. race (African-American, Caucasian > Asian, Latin-American) HTN (preeclampsia, gestational HTN , chronic HTN) : but, the severity of preeclampsia did not correlate with the incidence of abruption : Mg - reduce risk of placental abruption (Magpie Trial collaborative Group, 2002) external trauma : 2~6 hrs monitoring uterine leiomyoma : especially, located behind the placental implantation site

15. Recurrent Abruption - recurrence rate : 1 in 8 pregnancies - fetal death rate was increased in a second time - 1~3 wks earlier than the first time - suddenly occur ay any time : fetal well-being is normal beforehand, and thus not predictive ex.) NST, CST – normal 4 hrs later – placental abruption → killed the fetus

16. Pathology - hemorrhage into the decidua basalis → decidua splits, leaving thin layer adherent to the myometrium → decidual hematoma leads to separation, compression, and destruction of placenta - in early stage, no clinical symptom, a few centimeters in diameter (dark and clotted blood) → a very recent separated placenta appear no different from a normal placenta

17. - decidual spiral artery ruptures → retroplacental hematoma → expands disrupts more vessel & placenta → separation rapidly to the margin (because, the uterus still distended by conception, so it is unable to contract to compress the torn vessels that supply the placental site)

18. Concealed hemorrhage - placenta margins still remain adherent - placenta completely separated. but membranes retain their attachment to the uterine wall - blood gains to the amnionic cavity after breaking through the membrane - fetal head is closely applied to the lower uterus, blood cannot pass

19. Chronic placental abruption - retroplacental hematoma formation is somehow arrested completely without delivery • Fetal-to-maternal hemorrhage - placental abruption bleeding : almost maternal - fetal bleeding : non traumatic (20%, <10ml) traumatic (tear or fracture of placenta)

20. Clinical diagnosis sign or symptom frequency(%) vaginal bleeding 78 uterine tenderness or back pain 66 fetal distress 60 preterm labor 22 high-frequency contractions 17 hypertonus 17 dead fetus 15

21. - but, vary ……. : profuse bleeding, but placental separation may not so extensive to compromise the fetus : no external bleeding, but completely sheared off and the fetal dead - ultrasound : infrequently confirms : negative finding do not exclude placental abruption

22. Shock - intensity of shock is seldom out of proportion to maternal blood loss - but, shock ≠ amount of hemorrhage (thromboplastin from decidua & placenta entered the maternal circulation and incited coagulopathy or amnionic embolism) - oliguria caused by inadequate renal perfusion : response to vigorous treatment

23. Differential diagnosis - severe form : diagnosis generally is obvious milder or common form : difficult - lab & diagnostic method : detect lesser degree of abruption accurately - painless bleeding : placenta previa painful bleeding : placental abruption → but, variable state - so, differential diagnosis is not simple !!!!!!!!

24. Consumptive coagulopathy - most common - hypofibrinogenemia, FDP↑, D-dimer↑, coagulation factor↓ → 30%, enough to kill the fetus - major mechanism : coagulation intravascularly & retroplacentally → the activation of plasminogen to plasmin → maintaining patency of the microcirculation

25. Renal failure - severe form of placental abruption : the consequence of massive hemorrhage : treatment of hypovolemia is delayed or incomplete - with preeclampsia : renal vasospasm is likely intensified - proteinuria is common without preeclampsia → blood & crystalloid solution apply !!!!!!

26. Couvelaire uterus (uteroplacental apoplexy) - extravasation of blood into the uterine musculature and beneath the uterine serosa, broad ligament - interfere with uterine contraction : severe postpartum hemorrhage but, not an indication for hysterectomy

27. Management - depending on gestational age, maternal & fetal status - blood & crystalloid and prompt delivery • Expectant management in preterm pregnancy : tocolytics, close observation …… : but, fetal distress was seen → prompt delivery & immediate treatment

28. Tocolysis : tocolysis improved outcome in a highly selected group (preterm, partial abruption) : Towers and co-workers(1995) Mg or terbutaline to 95 women → perinatal mortality : 5% (did not differ from the nontreated group) : placental abruption should be considered a contraindication to tocolytic therapy

29. Cesarean delivery : rapid delivery (fetus : alive but in distress) : Kayani and colleagues(2003) → at fetal bradycardia (33case) 22 was neurologic intact (with in 20 min :15) 11 was died or cerebral palsy (beyond 20 min: 8) : decision time is an important factor in neonatal outcome

30. Vaginal delivery : fetal death, no obstetrical complication : coagulation defect (∵incision site bleeding) → vaginal delivery ; hemostasis uterine contraction-pharmacologically or massage • Labor : hypertonic -baseline >50mmHg, rhythmic contraction 75~100mmHg

31. Amniotomy : as early as possible ∙ decrease bleeding from the implantation site ∙ reduce the entry into the maternal circulation of thromboplastin (but, no evidence) • Oxytocin : if no rhythmic uterine contraction - oxytocin is given in standard doses

32. Timing of delivery after severe placental abruption - when the fetus is dead or previable, there is no evidence that establishing a time limit fro delivery is necessary - maternal outcome depends on adequate fluid and blood replacement therapy rather than on the interval to delivery

33. <PLACENTA PREVIA> • Definition - the placenta is located over or very near the internal os of cervix - total partial marginal low-lying

34. - vasa previa : the fetal vessels course through membranes and present at the cervical os

35. - the degree of placenta previa : the cervical dilatation at the time of examination ex) 2cm : low-lying 8cm : patial - spontaneous placental separation is inevitable due to the formation of the lower segment and cervical dilatation → vessel disrupted - digital palpation can incite severe hemorrhage !!!

36. Incidence - 1 in 305 deliveries (Martin, 2002) 1 in 300 deliveries (Crane, 1999) • Prenatal morbidity and mortality - neonatal mortality : threefold higher (∵ preterm birth) - fetal anomalies : 2.5-fold (reasons are unclear) - growth restriction : 20 % - low birthweight: due to preterm birth and growth impairment

37. Etiology - maternal age : 1 in 1500 (<19 yrs old) 1 in 100 (>35 yrs old) - multiparity - multifetal gestations - prior cesarean delivery : 1.9 % (2 times c/sec) 4.1% (>3 times c/sec) →prior uterine incision with a previa increases the incidence of cesarean hysterectomy - smoking : CO hypoxemia → compensatory placetal hypertrophy

38. Clinical findings - painless hemorrhage, usuallydoes not appear until near the end of the 2nd trimester or after - the initial bleeding is rarely so profuse as to prove fatal, usually cease spontaneously - because the lower segment contracts poorly compared with the body, hemorrhage from implantation site may continue after delivery - bleeding from cervical or lower segment laceration following manual removal

39. Placenta accreta, increta, and percreta - placenta previa is associated placenta accreta - because of poorly developed decidua in the lower uterine segment - 7% of 514 case of previa (Frederiksen, 1999) • Coagulation defects - rarely - because of thromboplastin escape through the cervical canal rather than into the maternal circulation

40. Diagnosis - uterine bleeding during the later half of pregnancy - unless a finger is passed through the cervix and the placenta is palpated  but, digital examination : torrential hemorrhage!!! - placental location can almost be obtained by sonography

41. Localization by sonography - transabdominal sonography : accuracy - 98% : false positive - ∵ bladder distention large placenta - transvaginal sonography : be superior than transabdominal sonogparhy : visualize cervical os in all case (70%, transabdomen) - transperineal sonography - MRI

43. Placental “Migration” - 18~20 weeks : low lying, not cover internal os → did not persist previa - midpregnancy : cover internal os → 40% persisted as a previa - during 2nd or early 3rd trimester : close but not cover → unlikely to persist as previa by term

44. - in absence of any other abnormality, so- nography need not be frequently repeated simply to follow place- ntal position - 28 weeks

45. - mechanism of placental movement : not completely understood - ‘migration’…… : clearly a misnomer, because invasion of chorionic villi into the decidua persist : and, relationship in a three-dimensional manner using two-dimensional sonography : differential growth of lower and upper myometrial segments as pregnancy progresses

46. Management - may be considered as follows: 1. fetus is preterm and no indication for delivery 2. fetus is reasonably mature 3. in labor 4. hemorrhage is so severe as to mandate delivery despite fetal immaturity

47. - preterm, but with no active bleeding : close observation - prolonged hospitalization may be ideal, however, usually discharged after bleeding has ceased and her fetus judged to be healthy → prepared to transport her to the hospital immediately

48. Delivery - cesarean delivery is necessary : incision (transverse or vertical) : if incision extends through the placenta, maternal or fetal outcome is rarely compromised - poorly contractile nature of the lower segment, there may be uncontrollable hemorrhage following placental removal (without accreta)

49. - hemostasis methods : oversewing the implantation site with chr #1-0 : bilateral uterine or internal iliac artery ligation : circular interrupted suture around the lower segment, above and below transverse incision with chr #1-0 : tightly packed with gauze, and then removed transvaginally 12 hours later : pelvic artery embolization  fail…….. Hysterectomy !!!!!

50. Prognosis - adequate transfusion and cesarean delivery : marked reduction in maternal mortality - serum AFP > 2,0 MOM : increased risk of bleeding early in the 3rd trimester and of preterm birth (Butler, 2001)