Abruptio placentae (Placental Abruption) - An overview

Contents

Complete/partial detachment of the placenta before delivery,

Usually after 20 weeks of gestation
M/C cause of APH
M/C cause of late pregnancy bleeding
M/C obstetric cause of DIC
1% pregnancy worldwide
MEDICAL EMERGENCY

Classification

Abruptio placentae: A, Mild abruption with concealed hemorrhage. B, Severe abruption with external hemorrhage. C, Complete separation with concealed hemorrhage. | Miller-Keane Encyclopedia: abruptio. (n.d.) Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. (2003). Retrieved October 19 2020 from https://medical-dictionary.thefreedictionary.com/abruptio

Partial separation (M/C)
- With concealed haemorrhage:
- With apparent haemorrhage
Complete separation

Etiology

Risk factors:

Previous placental abruption (M/C risk factor)
Hypertensive pregnancies (#2 M/C risk factor)
Trauma (#3 M/C cause)
Toxic metabolites (#4 M/C cause): Alcohol and cocaine use and cigarette smoking
Intrauterine growth restriction (IUGR)
Advancing maternal age
Male fetuses
Short umbilical cord (traction during delivery)
Prolonged rupture of membranes (>24 hours)
Thrombophilia
Polyhydramnios (sudden release of ↑ amniotic fluid)
Multiparity
Multiple pregnancy

Pathophysiology

Etiology
(Smoking, HTN, trauma, etc)
↓
Arterial degeneration
(at centre of placenta)
↓
Hemorrhage
↓
Separation of placenta
↓
Reduced O₂ delivery
(up to 25% reduction can be compensated)
↓
Expansion of bleed (central bleed) or vaginal bleeding (marginal bleed)
↓
↓ surface of O₂ exchange & ↓ maternal BP
↓
↓ O₂ delivery
↓
(Prolonged O₂ deprivation)
↓
Fetal organ damage

Presentation

Placental abruption usually presents as a combination of vaginal bleeding, uterine contractions, and pain.

Sudden-onset pain (abdomen + back) (from contractions d/t release of thromboplastin)
- Pain present between contractions

Concealed abruptio:

Firm, tender, enlarged uterus (disproportionate to gestational age of fetus)
Decreased fetal movement
Decreased fetal heart rate

Page’s classification:

Grading of placental abruption | Etiology, Clinical Manifestations, and Prediction of Placental Abruption – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Grading-of-placental-abruption_tbl1_44631833 [accessed 19 Oct, 2020]

Complications

MATERNAL
- Sheehan Syndrome
  - Perinatal pituitary necrosis
- Renal failure
- Disseminated Intravascular Coagulation (DIC) #1
  - Due to ↑ Thromboplastin release from placenta
FETAL
- Intrauterine hypoxia & asphyxia
- Premature birth #2
Hypovolemic shock (Maternal and/or fetal) #3
Death
- Maternal (0.5-5%)
- Fetal (35-80%)

Diagnosis

Transabdominal ultrasound:
Investigation of choice

"U/S OB trauma limited" — “U/S OB trauma limited” post motor vehicle collision, showing notable posterior placenta with a heterogeneous echotexture structure extending anteriorly | U/S, ultrasound; OB, obstetric; findings were concerning for placental abruption. | Page N, Roloff K, Modi A P, et al. (September 09, 2020) Management of Placental Abruption Following Blunt Abdominal Trauma. Cureus 12(9): e10337. doi:10.7759/cureus.10337

Management

Maternal/fetal risk → C-section
Term & stable → Vaginal delivery
Preterm & stable → Admit & observation