Fetal Demise: Causes of Intrauterine Fetal Heart Stoppage

Cessation of fetal heart activity (intrauterine fetal demise) has diverse etiologies; often multifactorial.

Placental / Cord Causes

• Placental abruption: Premature separation → acute hypoxic insult.
• Umbilical cord accidents: True knots, nuchal cord ×≥2, cord entanglement, prolapse, velamentous insertion, vasa previa.
• Placental insufficiency: Chronic hypoxia → growth restriction → demise (hypertensive disorders, diabetes, autoimmune).

Fetal Factors

• Genetic/structural anomalies: Trisomies, cardiac defects, CNS malformations.
• Infection: TORCH (toxoplasma, rubella, CMV, HSV, syphilis), parvovirus B19, Zika.
• Isoimmunization: Rh/ Kell alloimmunization → hydrops fetalis.

Maternal Conditions

• Preeclampsia/eclampsia, HELLP.
• Pre‑existing diabetes, renal disease, SLE, APS.
• Trauma (MVA, fall).
• Substance use (cocaine, tobacco).

Rare Catastrophic Events

• Amniotic fluid embolism (maternal + fetal collapse).
• Uterine rupture.

Post‑Demise Management

• Confirm with real‑time ultrasound.
• Offer induction (misoprostol ± oxytocin) vs. expectant management (limited time).
• Workup: Fetal autopsy (gold standard), placental pathology, karyotype/microarray, maternal labs (APS, thyroid, glucose, TORCH).
• Bereavement support, photography, mementos.

Recurrence risk depends on identified cause; most isolated losses have low recurrence.