Large for Gestational Age Flashcards
What is large for gestational age (LGA)?
Babies are defined as being large for gestational age (also known as macrosomia) when the 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.
What causes macrosomia?
- Constitutional
- Maternal diabetes
- Previous macrosomia
- Maternal obesity or rapid weight gain
- Overdue
- Male baby
Whar are the risks of LGA to the mother?
The risks to the mother include:
- Shoulder dystocia
- Failure to progress
- Perineal tears
- Instrumental delivery or caesarean
- Postpartum haemorrhage
- Uterine rupture (rare)
What are the risks of LGA to the baby?
The risks to the baby include:
- Birth injury (Erbs palsy, clavicular fracture, fetal distress and hypoxia)
- Neonatal hypoglycaemia
- Obesity in childhood and later life
- Type 2 diabetes in adulthood
What investigations are used to monitor LGA?
Investigations for a large for gestational age baby are:
- Ultrasound to exclude polyhydramnios and estimate the fetal weight
- Oral glucose tolerance test for gestational diabetes
Briefly describe the delivery process for LGA
Most women with large for gestational age pregnancy will have a successful vaginal delivery. NICE guidelines (2008) advise against induction of labour only on the grounds of macrosomia.
What is the main complications of LGA?
The main risk with a large for gestational age baby is shoulder dystocia.
How can the risks of shoulder dystocia at delivery be reduced?
The main risk with a large for gestational age baby is shoulder dystocia. The risks at delivery can be reduced by:
- Delivery on a consultant lead unit
- Delivery by an experienced midwife or obstetrician
- Access to an obstetrician and theatre if required
- Active management of the third stage (delivery of the placenta)
- Early decision for caesarean section if required
- Paediatrician attending the birth
