8.10 Large for Gestational Age

Question 1

What newborn weight is classed as macrosomia / LGA?

Answer 1

Newborn more than 4.5kg

Question 2

What estimated fetal weight is classed as LGA?

Answer 2

above the 90th centile is LGA

Question 3

Causes of LGA / macrosomia?

Answer 3

• constitutional (ie large parent etc)
• maternal DIABETES
• maternal obesity or rapid weight gain
• overdue
• male baby

Question 4

What are the risks to mother and to foetus of a foetus being LGA?

Answer 4

Mothers risk:

• shoulder DYSTOCIA
• failure to progress
• perineal tears
• instrumental delivery / caesarean
• postpartum haemorrhage
• uterine rupture (rare)

Foetus/ baby risk:

• birth injury (Erb’s palsy, clavicular fracture, fetal distress and hypoxia)
• neonatal hypoglycaemia
• obesity in childhood and later
• T2DM in adulthood

Question 5

What is the management of LGA during pregnancy?

Answer 5

• US scan to exclude polyhydramnios and estimate fetal weight
• OGTT for GD

Question 6

How can the risks of macrosomia delivery be reduced?

Answer 6

• deliver on a consultant lead unit
• experienced midwife / obstetrician
• active management of third stage (delivery of placenta)
• early decision for a c-section if required
• paediatrician attending the birth