Obstetric Topic 38. Intrauterine fetal death. Postterm pregnancy

I. Intrauterine Fetal Death / Stillbirth

Definition and Causes

• IUFD / stillbirth: fetal death after viability and before onset of labor; local teaching often uses ≥24 weeks.
• Definitions vary internationally; many use ≥20 weeks, while WHO comparison often uses ≥28 weeks.
• Maternal causes: hypertension, preeclampsia/eclampsia, diabetes/GDM, APS/thrombophilia, trauma.
• Infections: TORCH, syphilis, listeria and other severe maternal/fetal infections.
• Placental/cord causes: placental abruption, placenta previa bleeding, placental insufficiency/FGR, cord prolapse/cord accidents, vasa previa.
• Fetal causes: congenital malformations, chromosomal/genetic disease, hemolytic disease.
• Other associations: postterm pregnancy, severe growth restriction, multiple gestation; some cases remain unexplained.

Clinical Features and Diagnosis

• Typical complaint: cessation or marked reduction of fetal movements.
• Examination: absent fetal heart sounds, uterus smaller than expected or no interval growth.
• Diagnosis: real-time ultrasound/Doppler confirms absent fetal cardiac activity and absent fetal movement.
• After diagnosis: examine placenta/cord/membranes and consider fetal/genetic/infection/APS testing according to history and parental wishes.

Management

• If mother is stable, parents do not need to be rushed; management depends on maternal condition, gestational age and preference.
• Expectant management: wait for spontaneous vaginal delivery; prolonged retention can rarely cause DIC.
• Induction of labor: commonly offered to shorten waiting time and reduce DIC/anxiety risk.
• Vaginal delivery is preferred unless contraindicated; cesarean only for maternal indication or impossible vaginal delivery.
• If DIC develops: deliver/evacuate uterus and replace blood products/coagulation factors.

Prevention / Next Pregnancy

• Regular prenatal care and early detection of high-risk conditions: hypertension, diabetes, Rh/antibody problems, infection, FGR and postterm pregnancy.
• Prompt assessment of reduced fetal movements.

II. Postterm Pregnancy

Definition and Etiology

• Postterm pregnancy: ≥42+0 weeks from LMP/estimated due date.
• Incidence: about 5-10% depending dating accuracy and population.
• Common reason for apparent postterm pregnancy: inaccurate dating; prevent with 1st-trimester ultrasound.
• Risk factors: previous postterm pregnancy, nulliparity, obesity, family tendency.

Fetal and Maternal Consequences

• Placental aging → uteroplacental insufficiency → fetal hypoxia, oligohydramnios, meconium passage and IUFD.
• Meconium aspiration syndrome.
• Postmaturity syndrome: wasted thin fetus, dry peeling skin, long nails, reduced subcutaneous fat.
• Macrosomia → shoulder dystocia, perineal trauma, postpartum hemorrhage and operative delivery.

Management

• Accurate dating: 1st-trimester ultrasound.
• Fetal surveillance from term/postdates according to protocol: NST/CTG, BPP and AFI, often twice weekly if expectant management.
• From 41+0 weeks: induction is generally recommended/offered for uncomplicated singleton pregnancy.
• Deliver earlier if surveillance is abnormal, oligohydramnios appears, fetal movements decrease, fetal distress occurs or maternal indication develops.
• Mode: induction of labor if vaginal birth is not contraindicated; cesarean for usual obstetric indications.