1. Placental Abnormalities
Christina Rust, MSN, RNC-OB
1

2. Bleeding In Pregnancy
 5% of all women experience some kind of
vaginal bleeding during the 3rd trimester
 Two major causes:
- Placenta Previa
- Abruption
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 404.
2

3. 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

4. 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. 4
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 404.

5. Placenta Previa
5

6. 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.
6
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 404.

7. 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. .
7
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 404.

8. 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.

9. 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 9
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 405-6.

10. 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
10
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 406.

11. 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

12. 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

13. Risk Factors for Placenta Previa
 Hypertension, diabetes
 Advanced maternal age
 African Americans or Asians
 Cigarette smoking
13

14. 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

15. 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

16. 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
16
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 406-7.

17. 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
17
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 408.

18. 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
18
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 407.

19. 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)
19
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 407 .

20. 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
20
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 407-8.

21. 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

22. 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
22
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 407.

23. Fetal Outcome
 Fetal mortality – 20 %
- Prematurity
- Hypoxia
- Severe anemia
23

24. Fetal Outcome
 Fetal morbidity
- Preterm birth
- IUGR
- Fetal anemia
- Malpresentation
- Developmental disorders
24

25. Abruptio Placenta - Definition
 Separation of the placenta from its uterine
site of implantation after 20 weeks
gestation, but before delivery of the fetus.
25
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 392.

26. 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 separates
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 393. 26

27. 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

28. 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

29. 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.

30. 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

31. 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
31
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 397.

32. 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
32
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 395.

33. 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
33
Gilbert, E.S. (2007). High risk pregnancy & delivery(4 ed.). St. Louis, MI : Mosby Elsevier, p. 392.
th

34. 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 Anomalies
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.).
St. Louis, MI : Mosby Elsevier, p. 392.
34

35. 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.

36. 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
36
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 392.

37. 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
37
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 392.

38. 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

39. 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

40. 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

41. 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

42. Diagnosis of Abruptio Placenta
 Serum markers are being studied
- MSAFP associated with a 10X increase
in abruption
- hCG
- Inhibin A
42

43. 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. 44

45. 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

46. Fetal Outcomes
 Cause of 12% of
stillborns
 Prematurity
 Hypoxia
 Anemia
 IUGR
 Neurologic deficts
46
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 392.

47. 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 47
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 399-400.

48. 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 48
Gilbert, E.S. (2007). High risk pregnancy & delivery(4 ed.). St. Louis, MI : Mosby Elsevier, p. 399-400.
th

49. 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

50. 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

51. Velamentous Insertion of the Cord
51

52. 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. 53

54. 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.
54
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MO.: Mosby Elsevier, p.414.

55. Vasa Previa
55

56. 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
56
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 414.

57. Vasa Previa
 Risk Factors
- Succenturiate or low lying placenta
- Multiple gestations
- No Wharton’s jelly - cord compression-
fetal hypoxia - fetal death 75% of time
57
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 415.

58. 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.
58
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 414.

59. Circumvelate Placenta
The fetal surface of the placenta is
exposed through a ring of chorion and
amnion opening around the umbilical cord
59

60. 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

61. 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

62. Succenturiate Placenta
62

63. Battledore Placenta
 Cord is inserted at or near the placental
margin rather than in the center
63

64. Battledore Placenta
64

65. 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.
65
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 415.

66. 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 rectum
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 415. 66

67. 67

68. 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

69. 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

70. 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

71. 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
71
Gilbert, E.S. (2007). High risk pregnancy & delivery(4th ed.). St. Louis, MI : Mosby Elsevier, p. 413.

72. Outcome of Placenta Accreta
 Hemorrhage – Average blood loss 3000ml
to 5000 ml
 Shock
 Hysterectomy
 Uterine inversion
 Infection
 Maternal death 72

73. 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

74. 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

75. 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

76. 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 fetus
Amniotic Band Syndrome retrieved on May 31, 2009 from http://www.fetalcarecenter.org
76
Mattson, S. & Smith, J.E. (2004). Core curriculum for maternal-newborn nursing (3rd ed.). St. Louis, MO.: Elsevier Saunders,. p.
61-62.

77. 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 present
Amniotic Band Syndrome retrieved on May 31, 2009 from http://www.fetalcarecenter.org 77

78. 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.

79. Amniotic Band Syndrome (ABS)
79