Weight of the newborn is more than 4.5kg at birth; during pregnancy, an estimated fetal weight above the 90th centile is considered large for gestational age

Aetiology

• Fetal macrosomnia
• Polydramnios - excess amniotic fluid
• Maternal diabetes
• Multiple pregnancy
  • Monozygotic - splitting of a single fertilised egg
  • Dizygotic - fertilisation of 2 ova by spermatozoa
  • Chorionicity - 1 or 2 placentas
    • Important to determine via USS because monochorionic/monozygous twins are at higher risk of pregnancy complications
• Maternal obesity

Clinical features

Clinical features of multiple pregnancy

Symptoms

• Exaggerated pregnancy symptoms e.g. excessive sickness/hyperemesis gravidarum

Signs

• High AFP
• Large for dates uterus
• Multiple fetal poles

Investigations

• Ultrasound:
  • Fetal macrosomnia - USS EFW >90 centile or AC >97 centile
  • Polyhydramnios - AFI > 25, DVP >8cm
    • Fetal survey - lips, stomach
  • Multiple pregnancy - confirmed at 12 weeks
    • Shape of membrane and thickness of membrane
    • Fetal sex
    • Chorionicity

Management

Fetal macrosomia

• Exclude diabetes