Abnormal placentation/bleeding in pregnancy

Question 1

Placenta accreda

(general definition)

Answer 1

• “Abnormal placental attachment due to absence of decidua basalis and incomplete development of fibrinoid (Nitabuch) layer”
• Fibrinoid tissue deposits (nitabuch) incomplete → abnormal/increased invasion of trophoblasts into decidua basalis → bound to uterus (doesn’t separate after birth)
• One of the most serious complications of pregnancy → risk of maternal mortality
• U/S picks up 80-90% of time with experienced sonographers

Question 2

Name/describe 3 variations of placenta accreda

Answer 2

• Accreda vera - adherence to myometrium
• Increda - growth INTO the myometrium
• Percreta - growth through uterine wall and adheres to other structures and maybe bladder/bowel (depending on where it attaches)
• Bonus:
  
  • Partial accreda – placenta can being to separate (aka abrupt) → see bleeding

Question 3

Placenta accreda

Incidence + risk factors

Answer 3

• Incidence 1 in 533 birth,
• Risk factors:
  
  • Placenta previa
  • Prior c/s or myomectomy (scar on uterus)
  • Also: increased parity, maternal age, submucosal fibroids, female fetus

Question 4

Management/Complications of placenta accreda

Answer 4

• Cesarean at 34-0 to 35-6
• Risk of massive post partum hemorrhage in 2/3 patients, requiring cesarean and hysterectomy

Question 5

Vasa previa

Answer 5

• Fetal vessels run through the membranes over the cervix unprotected by the umbilical cord or placental tissue
• Associated with velementous insertion but more rare.
  
  • 0.04-0.02% pregnancies
• Associated low lying pregnancies, multiple gestation, resolved previa
• Must plan cesarean before membranes rupture​
  
  • sometime between 34-6 to 36-0

Question 6

Placenta previa

Definition, types

Answer 6

• Placenta implanted very close to or over internal Os of uterus
• Types: Complete, partial, marginal, low lying (not really a previa)

Question 7

Risk factors for placenta previa

Answer 7

• Advanced maternal age > 35
• Multiparity
• Prior cesarean section - 0.3-0.7%, higher with 1st section and goes up with each subsequent one
• Infertility treatments
• Smoking
• Unexplained elevated alpha-fetoprotein (AFP)
• Multiple gestation
• Short interpregnancy interval
• Prior uterine curettage

Question 8

Main symptom of placenta previa

Answer 8

• Painless vaginal bleeding
• Usually self limiting and presents in late 2nd or early 3rd
  
  • 1st episode often stops after a few hours
  • Subsequent bleeds tend to become worse (deattachment from LUS)
• Some may experience pain/cramping due to uterine irritibility
• Don’t do a digital exam on someone that has painless vag bleeding who hasn’t had an ultrasound showing no previa (ie if you don’t know if they have a previa). Speculum exam is ok
• Hard to tell if/when they might bleed again or be delivered

Question 9

Placenta previa monitoring/management

Answer 9

• Serial US to assess placental location and fetal growth
• Avoidance of cervical examinations and intercourse
• Activity restrictions
• Counseling regarding labor symptoms and vaginal bleeding
• Dietary and nutrient supplementation to avoid maternal anemia
• Early medical attention if any vaginal bleeding occurs.
• Asymptomatic (no bleeding) → expectant mgmt as long as compliant and live close to hospital
• Bleeding previa → hospitalization/monitoring/stabilization
  • < 34 wks → steroids
• Cesarean
• H/H, Ferritin if chronic

Question 10

Placental abruption

Answer 10

• Antepartal decidual hemorrhage leading to premature separation of the placenta.
• Often caused by rupture of maternal vessels in the decidua basalis, where it comes into contact with the anchoring villi of the placenta.
• Bleeding is almost always maternal in origin.
• 1% of all pregnancies

Question 11

Placental abruption risk factors

Answer 11

• Usually defect in maternal vessels
• HTN (chronic, gestational, PEC), interpregnancy interval < 1 year doubles risk
• PPROM
• Smoking - dose dependent relationship with # cigs smoked
• Trauma
• Cocaine
• Older maternal age
• Polyhydramnios
• Multiple gestation
• Fibroids
• Thrombophelias

Question 12

Peak occurance of placental abruption

Answer 12

• 24-26 weeks
• Recurrence 5-17% higher with more episodes

Question 13

Placental abruption presentation and differentials

Answer 13

• Vary markedly → can make dx difficult
  
  • Acute vs chronic
  • Overt vs concealed
  • Severity
• Hard abdomen
• Colicky cramping pain that is on/off that makes her irritates, anxious, uncomfortable,
• Vaginal bleeding
• Maternal tachycardia or non-reassuring FHR
• Grades:
  
  • 1, 2 (more vag bleeding),
  • 3 (severe bleeding and maternal VS changes, risk of DIC)

Differentials: previa, cervical bleeding/infection/cancer, vag trauma

Question 14

Placental abruption potential complications

Answer 14

• Maternal
  
  • Significant blood loss →
    
    • Shock
    • Consumptive coagulopathy
    • Renal failure
    • Death
  • Couvelaire uterus - blood seeping into the uterine musculature
  • High recurrence rate in subsequent pregnancies.
• Fetal
• Decreased oxygenation →
  
  • Cerebral compromise
  • Stillbirth.

Question 15

Amniotic bands

Answer 15

• Amniotic sacs folds and constricts areas of the fetus → amputation of fingers, limb, palate issues (if comes across face)
• Can be assiciatied with miscarriage
• Not likely to reoccur

Question 16

Placental abruption management

Answer 16

• Ultrasound evalutation - retroplacental clotting indications abruption
  
  • Normal U/S does not rule out abruption
• CBC, Type and screen, Coags, FIbrinogen
• IV access
• Contonuous FHR monitoring
• Rhogam if Rh neg (Kleihauer-Betke test to determine dose)
• Management depends on GA and maternal and fetal statuses
  
  • Small abruption < 34 wks → expectant mgmt
  • At/near term → delivery (induction/augmantation ok as long as closely monitored)
• Obstetrical emergency → REFER

Question 17

Bleeding in the 1st half of pregnancy

Etiologies

Answer 17

• Non-pregnancy causes: cervical polyp, sex, sti’s, hemorrhoids, hematuria
• Subchorionic bleed/hematoma - bleeding due to seperation of chorion to uterine lining. Usually self-resolve and good outcome if occurs early in 1st tri and is small
• Fibroids - bleeding if intramural fibroid twists on its stalk or placenta implants over one. Increase risk of pregnancy loss
• Spontaneous pregnancy loss - may manage expectantly, use misoprostol, or aspiration. Rhogam for Rh negative
• Ectopic
• Gestational trophoblastic disease (hydatidiform mole) - chorionic villi don’t develop properly → not viable pregnancy → normal pregnancy process turns into benign tumor, can also be malignant

Question 18

Rhogam

Answer 18

• CHECK BLOOD TYPE the minute of a report of 1st or 2nd trimester bleeding → need to prevent isoimmunization if mother is Rh negative
  
  • If FOB is Rh + (D antigen) fetus can be Rh+ → any blood mixing → maternal isoimmunization → can cause hemolytic anemia in fetus/hydrops in future pregnancy → may never be able to carry Rh+ fetus again
• Rhogam – antibodies that compete with other antibodies to bind to the D antigen → prevents mom from having a reaction to foreign antigen
• Rhogram dosing: any dose lasts 12 weeks
  
  • 50 mcg = microdose given at < 12 weeks for 1st trimester.
    
    • Lasts for 12 weeks (needs to be redosed after 12 weeks if there is another bleed)
  • 300 mcg dose at 28 weeks
  • KB test (fetal screen) – looks at certain volume of blood – determines percentage of fetal cells – if increased give a bigger dose (ie if placenta abruption)
• Give post partum Rhogam dose within 72 hours if baby is Rh+
• Blood product – risk of contaminants and theoretical risk of mad-cow, More common: injection site reactions, fever, allergic reaction to IgA in rhogam

Question 19

Bleeding during second half of pregnancy

Etiologies

Answer 19

• Placenta previa
• Placental abruption

Question 20

Bleeding during second half of pregnancy

General managment

Answer 20

• Review Rh status
  
  • Rhogam if Rh negative
  • KB test
• Review placental location on US reports or perform US
  
  • Avoid digital exam unless US has r/o previa
  • Transvaginal US best
• Assess uterine tone
• Vital signs
• Potential hospitalization

Question 21

Identify scope of practice for CNM/WHNP when caring for the woman with placental/fetal growth abnormalities in the third trimester

Answer 21

• 2nd + 3rd trimester bleeding almost always abnormal → MD collaboration or referral