Large for Gestational Age

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 presentation

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
  • Reassure
  • Conservative vs IOL vs C/S delivery
  • If EFW >/= kg offer C/S

Polyhydramnios

  • IOL by 40 weeks
  • Risks during labour include malpresentation, cord prolapse and PPH
  • Neonatal examination

Multiple pregnancy

  • Twin/multiple pregnancy clinic
  • Maternal education
  • Medications - iron, low dose aspirin, folic acid
  • Increased USS surveillance

Complications

Multiple pregnancy

  • Fetal includes congenital anomalies, IUD, pre-term birth, growth restriction, cerebral palsy, twin to twin transfusion
  • Maternal include hyperemesis gravidarum, anaemia, pre eclapsia

Fetal macrosomia

  • Clinician and maternal anxiety
  • Labour dystocia
  • Shoulder dystocia (more with diabetes)
  • PPH