Overview

• Macrosomia → weight of newborn is >4.5kg at birth. During pregnancy, esitmated fetal weight >90th percentile.
  • Causes → constitutional, maternal gestational diabetes, previous macrosomia, maternal obesity, overdue, male baby.
  • Risks to Mother → shoulder dystocia, failure to progress, perineal tears, instrumental delivery or caesarean, PPH, uterine rupture.
    • Shoulder Dystocia → inability to deliver the body of the fetus using gentle traction, the head having already been delivered. Usually occurs due to impaction of the anterior fetal shoulder on the maternal pubic symphysis.
  • Risks to Baby → birth injury, neonatal hypoglycaemia, obesity in childhood and later life, T2DM in adulthood.
• 3 tools to diagnose large for age prenatally → symphysis-fundal height (SFH), abdominal circumference (AC), estimated fetal weight (EFW).
  • After 24 Weeks → only expect the fundal height to increase by 1cm a week (any quicker = potentially large for dates).

Making Diagnosis

Clinical Features

• O/E → excessive distension for gestational age.
• Abdomen → increased SFH, increased abdominal circumference.

Investigations

• Ultrasound → exclude polyhydramnios and estimate fetal weight.
• OGTT → gestational diabetes.

Management Plan

• Reduce risk of Shoulder Dystocia → offer caesarean section.

Complications →

Prognosis →