Harvey's Garden

Abnormal labor and delivery

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Umbilical cord complications

Vasa Previa

  • Pathophysiology
    • Fetal blood vessels traverse the fetal membranes across the internal cervical os.
    • Vessels are unprotected by Wharton jelly → prone to rupture upon membrane rupture.
    • Associated with Velamentous Cord Insertion and succenturiate placental lobes.
  • Clinical Features
    • Classic Triad:
      1. Membrane rupture
      2. Painless vaginal bleeding (fetal blood)
      3. Fetal bradycardia (<110 bpm) or death (exsanguination)
    • Differentiate from Placenta Previa (maternal blood, usually stable fetal heart rate initially).
  • Diagnostics
    • Prenatal: Transvaginal Ultrasound (Color Doppler) shows vessels over os.
    • Apt test (historic): Distinguishes fetal vs. maternal hemoglobin (fetal Hb is resistant to alkali).
  • Treatment
    • Emergency C-Section immediately upon diagnosis of bleeding/rupture.
    • If diagnosed prenatally: Elective C-section at 34-35 weeks.

Umbilical Cord Prolapse

  • Pathophysiology/Risk Factors
    • Umbilical cord descends below the fetal presenting part after membrane rupture.
    • RFs: Breech presentation, transverse lie, polyhydramnios, prematurity, long cord.
  • Clinical Features
    • Sudden onset of severe, prolonged fetal bradycardia or severe variable decelerations after membrane rupture.
    • Physical Exam: Palpable pulsating cord in the vagina. t
  • Management
    • Obstetric Emergency.
    • Manual elevation of the fetal presenting part (keep hand in vagina to lift head off cord) while moving to OR.
    • Maternal positioning: Trendelenburg or knee-chest position.
    • Emergency C-Section.

Velamentous Cord Insertion

  • Pathophysiology
    • Umbilical cord inserts into the chorioamniotic membranes rather than the placental mass.
    • Fetal vessels travel between amnion and chorion without protection of Wharton jelly before reaching the placenta.
  • Complications
    • ↑ Risk of Vasa Previa.
    • Vessel rupture causing fetal hemorrhage.
    • Intrauterine Growth Restriction (IUGR).

Single Umbilical Artery (2-Vessel Cord)

  • Anatomy
    • Normal: 2 Arteries (deoxygenated blood), 1 Vein (oxygenated blood).
    • Pathology: Aplasia or atrophy of one umbilical artery.
  • Associations
    • Can be an isolated finding in normal pregnancies.
    • ↑ Risk of congenital anomalies, specifically Renal (do fetal renal ultrasound) and Cardiac.
    • Associated with Aneuploidy (Trisomy 13, 18).

Nuchal Cord & True Knots

  • Nuchal Cord
    • Cord wrapped around fetal neck (very common).
    • Fetal Heart Rate Tracing: Variable decelerations (abrupt drop and return) due to cord compression.
    • Management: Usually benign; monitor. Reduce cord at delivery if tight.
  • True Knots
    • Rare; cord ties into a knot.
    • RFs: Monoamniotic twins (cords entangle), polyhydramnios, long cord.
    • Complication: Fetal asphyxia if knot tightens.

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