Define and describe the causes, diagnosis, complications and management of intra-uterine Fetal Death.

Retained dead fetus beyond 4 weeks risks consumptive coagulopathy.

Definition

Intra-uterine fetal death (IUFD) is death of the fetus in utero after 28 weeks of gestation (period of viability) and before the onset of labour. (Death before viability is an early fetal/missed loss.)

Intra-uterine Fetal Death - Approach

Causes

• Maternal — pre-eclampsia/eclampsia and chronic hypertension, diabetes, antepartum haemorrhage, severe anaemia, infections, Rh isoimmunisation, antiphospholipid syndrome and post-term pregnancy.
• Fetal — congenital malformations and chromosomal abnormalities, cord accidents (true knot, prolapse, entanglement), and severe growth restriction.
• Placental — abruption, placental insufficiency and infarction.
• A proportion remain unexplained.

Diagnosis

• Symptoms/signs — cessation of fetal movements, retrogression of breast changes, a uterus smaller than dates and not enlarging, and absent fetal heart sounds.
• Ultrasound (confirmatory) — absent cardiac activity and fetal movements; later, overlapping skull bones and collapse of the fetal pole.
• Radiological signs (after several days) — Spalding's sign (overlapping of skull bones), Robert's sign (gas in the great vessels/heart), the "ball" sign (hyperflexion of the spine) and crowding of the rib shadows.

Complications

• Psychological distress to the mother and family.
• Disseminated intravascular coagulation (DIC) — release of thromboplastin from the retained dead fetus causes hypofibrinogenaemia, with a significant bleeding risk if the fetus is retained beyond 4 weeks.
• Infection of the uterine contents and, rarely, sepsis.

Management

• Confirm the diagnosis by ultrasound and break the news with empathy and support.
• Investigate the cause — blood pressure, urine protein, blood sugar, blood group and antibodies, infection screen, and a coagulation profile (fibrinogen, platelets) which is repeated while awaiting delivery.
• Induction of labour — most women prefer prompt delivery. With an unfavourable cervix, use mifepristone followed by misoprostol, or vaginal prostaglandins; oxytocin and amniotomy when the cervix is favourable. Vaginal delivery is the aim; caesarean section is reserved for obstetric indications.
• Manage coagulopathy — correct with fresh frozen plasma/cryoprecipitate if DIC develops; give anti-D to Rh-negative women.
• After delivery — examine the baby and placenta, offer autopsy and karyotyping to establish the cause, suppress lactation, provide grief support and counsel about future pregnancies.

WHY a Retained Dead Fetus Threatens the Mother's Coagulation

Understanding why a dead fetus retained in the uterus endangers the mother explains the urgency of an apparently 'non-urgent' situation — the baby, after all, is already dead. The danger is disseminated intravascular coagulation. The macerating fetus and degenerating placenta slowly release thromboplastin into the maternal circulation, activating the coagulation cascade; over weeks this consumes fibrinogen, platelets and clotting factors, producing a consumptive coagulopathy. The risk becomes significant if the fetus is retained beyond about four weeks (occurring in roughly a quarter of such women), and may declare itself catastrophically as torrential haemorrhage at delivery, when the blood simply will not clot. This is why a retained dead fetus is never left indefinitely 'to come away on its own', why fibrinogen and the coagulation profile are monitored serially if spontaneous labour is awaited, and why delivery is expedited (usually induced with mifepristone and misoprostol) rather than delayed, with blood and clotting products available. Recognising that the dead fetus acts as a slow-release source of thromboplastin explains this entire approach.

WHY the Cause Must Be Sought — and WHY Grief Matters

Two aspects of intrauterine fetal death are easily neglected yet central to good care. The first is why a systematic search for the cause is essential, even though it cannot help this baby — it can help the next one. A cause is found in many cases: hypertensive disease, abruption, diabetes, infection, congenital or chromosomal abnormality, cord accident, Rh isoimmunisation, antiphospholipid syndrome or thrombophilia — and identifying it permits specific treatment and surveillance in the next pregnancy (for instance aspirin and heparin in antiphospholipid syndrome), transforming the recurrence risk. Hence the recommended workup: maternal glucose and HbA1c, blood pressure and urine, a Kleihauer test, antiphospholipid antibodies, an infection screen, karyotype and — most informative of all — placental histology and, where accepted, post-mortem examination. The second is that this is a bereavement: the parents have lost a child, and their care must include sensitive communication, the opportunity to see and hold the baby, an explanation of the findings, suppression of lactation, contraceptive advice and follow-up counselling. Recognising that good management is both a search for answers and a response to grief explains why IUFD tests the whole clinician.

• IUFD = death of the fetus after 20 weeks (or ≥500 g) before delivery; diagnosed by absent fetal cardiac activity on ultrasound.
• The main maternal risk is DIC — thromboplastin from the dead fetus consumes clotting factors, especially after ~4 weeks' retention.
• Monitor fibrinogen and the coagulation profile; expedite delivery (mifepristone + misoprostol) rather than waiting indefinitely.
• Search for the cause: hypertension, diabetes, abruption, infection, anomaly, Rh disease, antiphospholipid syndrome — placental histology is the most informative test.
• Provide bereavement care: sensitive communication, seeing the baby, lactation suppression, contraception and follow-up counselling.