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Wiki.placental abnormalities1
 

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    Wiki.placental abnormalities1 Wiki.placental abnormalities1 Presentation Transcript

    • Placental Abnormalities Christina Rust, MSN, RNC-OB 1
    • Bleeding In Pregnancy 5% of all women experience some kind of vaginal bleeding during the 3rd trimester Two major causes: - Placenta Previa - AbruptionGilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 404. 2
    • Placenta Previa - Definition Abnormally implanted placenta placed totallly or partially in the lower segment of the uterus, rather than in the fundus. When the cervix begins to dilate and efface, the placenta separates, allowing bleeding from the open vessels .Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 405. 3
    • Three Categories of Placenta Previa Total/Complete – The placenta completely covers the internal cervical os in the third trimester.(20-43%) Partial – The placenta implants near and partially covers the internal os.(23-49%) Marginal – The edge of the placenta is within 2-3 cm of the internal os. (31%) * Low Lying – The exact relationship of the placenta to the internal os is unknown. 4Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 404.
    • Placenta Previa 5
    • Etiology of Placenta Previa Unknown cause – When the embryo is ready to implant and the decidua in the fundus is deficient, it will choose another spot lower in the uterine segment Placentas are larger on the maternal side, cord often has marginal or vellamentous insertion. Suggests that the placenta was growing toward more favorable decidua. 6Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 404.
    • Chorionic Villi Two types of chorionic villi - Opens up into intervillous spaces that support exchange of oxygen and nutrients between fetal and maternal circulation - Anchors the placenta to the wall of the uterus Chorionic villi growth normally stays within the endometrium because of the fibrinoid layer of Nitabuch. It separates the decidua from the myometrium and stops villi growth. . 7Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 404.
    • Theories of Placenta Previa Damage to endometrium or myometrium from surgery or infection Any process that prevents migration Impeded endometrial vascularization due to poor blood supply from hypertension, diabetes, cigarette smoking, AMA Early or late ovulation Large placental mass (multiples) 8 Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p.
    • Do Placentas Move? 90% of placentas that implant low migrate ↑ If > 2 cm cervical overlap migration is rare Migration - uterine growth from .5 cm to 5 cm causes movement of the placenta away from the cervical os Chorionic villi have the ability to grow in one area and be dormant in another area Lower uterine segment elongates while uterine fundus hypertrophies during 3rd trimester 9Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 405-6.
    • Placenta Previa Painless bright red vaginal bleeding – usually first bleeding episode not before 30 wks. Suspected with oblique or transverse lie (placenta prevents descent into pelvis) Diagnosed by U/S 80-90% bleeding occurs without warning Uterus non-tender – no rise in fundal height Accompanied by contractions 20% of the time 10Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 406.
    • Placenta Previa Often occurs when sleeping First episode of bleeding usually scant, then each episode more Hemorrhagic or hypovolemic shock Deliver by C/S if placenta covers cervix 11
    • Risk Factors for Placenta Previa Endometriosis after previous pregnancy Uterine scars – abortions, C/S, molar pregnancy Tumors altering the contour of the uterus Close pregnancy spacing Multiparity Large placenta 12
    • Risk Factors for Placenta Previa Hypertension, diabetes Advanced maternal age African Americans or Asians Cigarette smoking 13
    • Incidence of Placenta Previa Depends on which trimester of pregnancy - 2nd trimester – 45% of placentas in lower uterine segment. - 3rd trimester - .5 -1% in lower uterine segment 1 in 200 pregnancies Occurs more often in grand multiparas – 2% History of previa – 4-8% Previous C/S - 2nd C/S – no increase in risk, 3rd C/S– 2.2%, 4th or more C/S - 10% 14
    • Maternal Complications of Placenta Previa Antepartum, intrapartum, postpartum hemorrhage and hypovolemic shock - Lower uterine segment not as muscular, less able to contract Accreta, increta, percreta Anemia DIC Vasa Previa Renal failure 15
    • Maternal Complications of Placenta Previa Septicemia – opened blood vessels near cervical os and can become infected easily Prolonged hospital stay Thrombophlebitis Cesarean Section Abruption Fetal Malpresentation 16Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 406-7.
    • Medical Management Medical management depends on gestational age and severity of bleeding: - Bedrest with BRP - IV - 16 g angio (Hep lock if no active bleeding) - CBC, Type & Screen, platelet count, fibrinogen, bleeding time - Observe closely for s/s of bleeding - Steroids for lung maturity - Rhogam if indicated 17Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 408.
    • Medical Management Transvaginal ultrasound is modality of choice Transabdominal ultrasound lacks some precision in identifying placenta previa Serial U/S should be performed to check for placental placement, fluid level, and fetal growth 18Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 407.
    • Medical Management No pelvic exams – Sterile speculum exam to rule out other causes of bright red bleeding - Polyps - Cervicitis - Cervical carcinoma - Sexual abuse Controversy regarding tocolysis for contractions - bleeding causes uterine irritability (Magnesium sulfate not Brethine) 19Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 407 .
    • Medical Management No douching or intercourse NST daily, bi-weekly BPP Measure and mark fundal height Daily iron and vitamin supplement If HCT < 30% - transfuse O2 at 10 liters per non-rebreathing face mask Amniocentesis at 34-36 wks. C/S for large blood loss 20Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 407-8.
    • Medical Management at Home  May be D/C home after 72 hrs. without bleeding in 2nd trimester  Requires strict instructions for bedrest w/BRP, kick counts, and when to return to the hospital  Long term hospital stay for bleeding in 3rd trimester 21
    • Maternal Outcomes Mortality less than 1%, morbidity 20% Most will have at least one significant hemorrhage – 25 % will go into shock Vaginal and cervical lacerations occur more often with vaginal deliveries Poor endometrium may contribute to placenta accreta – 15 % Vasa previa more common with placenta previa 22Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 407.
    • Fetal Outcome Fetal mortality – 20 % - Prematurity - Hypoxia - Severe anemia 23
    • Fetal Outcome Fetal morbidity - Preterm birth - IUGR - Fetal anemia - Malpresentation - Developmental disorders 24
    • Abruptio Placenta - Definition Separation of the placenta from its uterine site of implantation after 20 weeks gestation, but before delivery of the fetus. 25Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 392.
    • Grades of Abruptio Placenta Grade 1(Mild) (48%) - Dark red vaginal bleeding mild/moderate (< 500 ml) - No uterine tenderness - Mild tetany - Reactive FHR strip - < 1/6 of placenta separatesGilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 393. 26
    • Grades of Abruptio Placenta Grade 2 (Moderate)- (27%) - Dark red vaginal bleeding (1000-1500 ml blood loss) but may be concealed - Gradual or abrupt onset of abdominal pain - Tetanic contractions possible - Maternal tachycardia, tachypnea, BP okay - Nonreassuring FHR tracing - S/S DIC, fibrinogen 150-300 mg/dl - 1/6 to 1/2 of placenta separates 27 th
    • Grades of Abruptio Placenta Grade 3 (Severe) - (24%) - Mod. to severe dark red bleeding(> 1500 ml) - > 1/2 of placenta separates - Tetanic contractions/ boardlike abdomen - Usually abrupt knife-like abdominal pain - Profound maternal hypovolemia and shock - Significant fetal compromise including death, - DIC, fibrinogen < 150 mg/dl . Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 393 28
    • Classifications of Maternal Bleeding  Marginal or apparent - Separation near edge of placenta and blood can escape  Central or concealed - Separation in center of placenta and blood is trapped  Mixed or combined - Part of separation is at the edge and part in the center of placenta 29 Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 392.
    • Incidence of Abruptio Placenta Incidence 1:150 History of abruption - 5-17% 10X greater risk in subsequent pregnancies Smoking - 90% increase in risk (Ananath 1999) Occurs in approximately 1% of primips, 2.5% of multips 30
    • Incidence of Abruptio Placenta Mortality rate - Maternal - 1% (14 in 1,000) - Fetal - 25 to 30 % One of the leading causes of fetal and neonatal mortality rates 80% of all abruptions occur before the onset of labor 31Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 397.
    • Etiology of Abruptio Placenta Exact cause unknown Possibly begins with degenerative changes in the spiral arteries that supply the intervillous spaces, resulting in thrombosis, degeneration of the decidua, necrosis, and finally rupture of the vessel. Bleeding occurs because uterus is distended and can’t contract down on blood vessels 32Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 395.
    • Etiology of Abruptio Placenta Hematomas form along with retroperitoneal clot, compressing adjacent placenta causing local destruction. Further bleeding causes increased pressure behind the placenta which causes further separation. Retroplacental hematoma (concealed bleed) releases large amounts of thromboplastin leading to DIC 33Gilbert, E.S. (2007). High risk pregnancy & delivery(4 ed.). St. Louis, MI : Mosby Elsevier, p. 392. th
    • Conditions Associated with Abruptio Placenta Chronic hypertension/Preeclampsia - 5X higher Short umbilical cord Trauma - 5% risk with minor trauma - 50% risk with major trauma - car accident, abuse, falls Hydramnios IV cocaine/crack use -10% Uterine AnomaliesGilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.).St. Louis, MI : Mosby Elsevier, p. 392. 34
    • OB Conditions Associated with Abruptio Placenta  History of abortions  Premature labor  Antepartum hemorrhage  Stillbirth or neonatal death  6X greater with parity > 7  Folic acid deficiency  Multiple gestation  PROM -5% risk Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI 35 : Mosby Elsevier, p. 393.
    • OB Conditions Associated with Abruptio Placenta Circumvallate placenta Hx of Abruption - recurrence rate 10% with 1 abruption, 25% with 2 abruptions Diabetes Uterine fibroids Extremes of maternal age Sudden uterine decompression Cigarette smoking - decidual necrosis 36Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 392.
    • Signs and Symptoms Depends on type of abruption, location and amount: - Abdominal or low back pain - 50% - Uterine hypertonus - 17% - Uterine contractions - 17% - Uterine tenderness - Severe knife-like pain with boardlike abdomen 37Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 392.
    • Signs and Symptoms Uterus could be tender at point of separation or may be generalized over entire abdomen Increases uterine distention – elevated fundal height Bleeding - minimal or diffuse - Dark red, vaginal bleeding – 80% - (dark because it has had time to begin clotting)Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 392. 38
    • Signs and Symptoms If some of the trapped blood is forced through fetal membranes into amniotic cavity, amniotic fluid become bloody Shock is severe Fetal distress or death Coagulopathy / DIC Hypovolemia 39
    • Diagnosis of Abruptio Placenta Based on hx., physical exam, lab values No analgesia / anesthesia until dx. confirmed Vaginal bleeding with or without pain /shock Increased uterine tone, tenderness, sustained tetanic contractions Fetal distress 40
    • Diagnosis of Abruptio Placenta U/S for placental localization - accurate 50 % of the time Palpation of abdomen, measure fundal height Confirm after delivery – inspect the placenta 41
    • Diagnosis of Abruptio Placenta Serum markers are being studied - MSAFP associated with a 10X increase in abruption - hCG - Inhibin A 42
    • Diagnosis of Abruptio Placenta Couvelaire Uterus – Abruption that is concealed – Builds up enough pressure under the placenta that it forces the blood into the myometrial muscle fibers – also known as a “Blue Uterus” 43
    • 44
    • Maternal Outcomes Renal failure from hypovolemia Blood transfusion DIC – 30% Amniotic fluid embolis Uterine rupture Postpartum endometritis Postpartum hemorrhage Prolonged hospitalization Cesarean section / hysterectomy 45
    • Fetal Outcomes  Cause of 12% of stillborns  Prematurity  Hypoxia  Anemia  IUGR  Neurologic deficts 46Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 392.
    • Medical Management R/O placenta previa Bedrest w/ BRP Ultrasound IV with large bore catheter Type & Crossmatch, CBC, platelet count, fibrinogen, bleeding time, PT/PTT Restore blood loss, correct coagulation defect Frequent vital signs Strict I & O 47Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 399-400.
    • Medical Management No tocolytics until diagnosis confirmed -Magnesium sulfate may be used to prolong pregnancy for 48 hrs. to give time for steroids to work. DO NOT use Brethine - It will mask signs of shock. Assess for signs of shock - cold, clammy skin, pale, anxious, thirsty Assess FHR and uterine activity Measure and mark fundal height Observe for signs of vaginal bleeding 48Gilbert, E.S. (2007). High risk pregnancy & delivery(4 ed.). St. Louis, MI : Mosby Elsevier, p. 399-400. th
    • Medical Management C/S for fetal distress, maternal blood loss or compromise, coagulopathy, poor labor progress Amniotomy to assess blood in fluid O2 per mask Avoid episiotomy Be aware of postpartum hemorrhage Provide emotional support Patient teaching Rhogam if indicated 49
    • Velamentous Insertion of the Cord Cord is implanted at the edge of the placenta Vessels of the cord separate at a distance away from the margin of the placenta surrounded only by a fold of amnion Minimal to no Wharton’s Jelly to protect the vessels Fetus may become hypovolemic and die quickly if vessels rupture If bleeding is seen, mother should be tested for fetal cells (Kleihauer-Betke) 50
    • Velamentous Insertion of the Cord 51
    • Velamentous Insertion of the Cord Increased incidence of structural defects: - Congenital hip dislocation - Asymmetrical head shape Increased risk for IUGR and preterm birth Occurs in 1% singleton births (1:1275 to 1:8333)Mattson, S. & Smith, J.E. (2004).Core curriculum for maternal-newborn nursing (3rd ed.). St. Louis, MO.: Elsevier 52 Saunders, p.64.
    • 53
    • Vasa Previa Rare circumstance that may occur with velamentous insertion of the cord where umbilical vessels cross the internal os presenting ahead of the fetus. Requires a C/S. 54Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MO.: Mosby Elsevier, p.414.
    • Vasa Previa 55
    • Vasa Previa Because fetal blood volume is only 80 to 100 ml., tearing of fetal vessels will cause hemorrhage and rapid fetal death No problem to the mother When the fetal membranes rupture 75-90 % of the time the velamentous vessels will rupture 56Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 414.
    • Vasa Previa Risk Factors - Succenturiate or low lying placenta - Multiple gestations - No Wharton’s jelly - cord compression- fetal hypoxia - fetal death 75% of time 57Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 415.
    • Vasa Previa Treatment - U/S - Observe for vaginal bleeding - especially after vaginal exam - Hospitalize at 30 - 32 wks. - Steroid management - C/S at 35-36 wks. 58Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 414.
    • Circumvelate PlacentaThe fetal surface of the placenta isexposed through a ring of chorion andamnion opening around the umbilical cord 59
    • Circumvelate Placenta Abnormally thickened placenta with smaller surface area over the uterine wall because membranes do not insert at the edge of the placenta. Villi are left uncovered by the membranes resulting in bleeding and increased possibility of abruption. 60
    • Succenturiate Placenta One or more accessory lobes of the villi have developed Vessels from the major to the minor lobes are only supported by membrane. Increase the likelihood that the minor lobe(s) may be retained during the third stage of labor. 61
    • Succenturiate Placenta 62
    • Battledore Placenta Cord is inserted at or near the placental margin rather than in the center 63
    • Battledore Placenta 64
    • Placenta Accreta A rare condition in which all or part of the placenta is unusually adherent to the myometrium. The normal spongy layer of the decidua is absent or defective allowing the placental villi to grow down through the endometrium into the myometrium. 65Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 415.
    • Types of Accretas Accreta – Chorionic villi adhere to the myometrium Increta – Villi invade into the myometrium Percreta – Villi invade into through myometrium and beyond the serosa layer, often into the bladder or rectumGilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 415. 66
    • 67
    • Placenta Accreta Predisposing Factors - Implantation over a previous C/S scar or other surgical scar in the uterine cavity - 2nd C/S - 10-25% risk , 3rd or more C/S – 40-50% risk - Previous curetagge - Prior hx. of endometritis or other endometrial trauma - High parity - Placenta previa – 5-10% 68
    • Placenta Accreta May involve one cotyledon, a few cotyledons, or all of the cotyledons Rate has increased over last 20 yrs., most likely due to the increase in C/S rate 1:2500 69
    • Signs and Symptoms None until delivery Depends on depth, site of penetration, number of cotyledons involved If accreta is partial some cotyledons may separate from uterine wall leaving open, bleeding vessels. Uterus unable to contract because of adherent placenta still within uterine cavity. Profuse hemorrhage occurs. If total accreta, tearing occurs when doctor tries to deliver placenta.Uterine inversion may occur. 70
    • Diagnosis Sometimes can be diagnosed by U/S or MRI – but not 100% effective Usually when attempt is made to remove the placenta and it will not come out 71Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 413.
    • Outcome of Placenta Accreta Hemorrhage – Average blood loss 3000ml to 5000 ml Shock Hysterectomy Uterine inversion Infection Maternal death 72
    • Treatment of Placenta Accreta Large bore IV catheter IV fluids, replace blood loss Ultrasound Type & Screen, CBC, platelet count, fibrinogen, Pt, PTT, bleeding time Accurate I & O Assess vital signs D & C / Hysterectomy DO NOT pull too hard on the umbilical cord 73
    • Other Causes of Bleeding in Pregnancy Vascular changes in cervix due to pregnancy Intercourse STIs’ – Chlamydia, Bacterial Vaginosis, Trichimoniasis Cervical change with preterm labor Uterine dehisence Cervical cancer 74
    • Cervical Cancer One in 34 women diagnosed with cervical cancer is pregnant Rare complication – 0.2% to 0.9% Remains the most common type of gynecologic malignancy Mean age of diagnosis is 31.8 years 75
    • Amniotic Band Syndrome Arise from rupture of amnion, usually at cord insertion site usually between 28 days after conception and 18 weeks of gestation Etiology unknown but results in floating strands and cords of the amnion Sticky floating bands that can adhere to fetusAmniotic Band Syndrome retrieved on May 31, 2009 from http://www.fetalcarecenter.org 76Mattson, S. & Smith, J.E. (2004). Core curriculum for maternal-newborn nursing (3rd ed.). St. Louis, MO.: Elsevier Saunders,. p. 61-62.
    • Amniotic Band Syndrome Incidence – 1:1,200 to 1;15,000 Possible causes: - Premature rupture of membranes - Inflammation and trauma - After amniocentesis - Oligohydramnios may be presentAmniotic Band Syndrome retrieved on May 31, 2009 from http://www.fetalcarecenter.org 77
    • Amniotic Band Syndrome Restricts embryonic development or causes structural abnormalities later in gestation - Anenecepahly - Cleft lip and palate - Choanal atresia - Limb reduction/amputations/syndactaly - Omphaloceles and gastrochesis - Ear deformities - Club feet 78 Mattson, S. & Smith, J.E. (2004). Core curriculum for maternal-newborn nursing (3rd ed.). St. Louis, MO.: Elsevier Saunders,. p. 61-62.
    • Amniotic Band Syndrome (ABS) 79