[32] Large for Gestational Age Flashcards
What is LGA often defined as?
Weight, length, or head circumference that lies above the 90th centile for that gestational age
What term is sometimes used for LGA?
Macrosomia
What is macrosomia defined as?
A baby bigger than 4kg at birth, regardless of gestational age
When are the risks associated with fetal macrosomia significantly increased?
When the birth weight is over 4.5kg
What is one of the main risk factors for macrosomia?
Poorly controlled diabetes, including gestational diabetes and pre-existing type 2 diabetes
What is pre-existing type 1 diabetes associated with?
More associated with SGA
What % of cases of macrosomia are caused by uncontrolled diabetes?
35-40%
What are other risk factors for macrosomia?
- Post-term pregnancy
- Maternal obesity
- Multiparity
- Prior macrosomic infant
- Male infant
- Increased maternal height
- Advanced maternal age
- Beckwith-Wiedemann syndrome
What % of cases of macrosomia are associated with post-term pregnancy?
10-20%
What % of cases of macrosomia are associated with maternal obesity?
10-20%
What is used to detect LGA?
Ultrasound
What is the limitation of using ultrasound to diagnose LGA?
Current ultrasound techniques are only accurate to within 15-20% of fetal weight
What should be done for women at high risk of having a macrosomic infant, or have a known LGA fetus?
Should be followed with serial ultrasound examinations every 3-4 weeks to chart fetal growth
What might be offered for delivery of a macrosomic infant?
Elective C-section
What is the purpose of elective C-section for the delivery of a macrosomic infant?
To prevent birth trauma
When should elective C-section be offered to women with a macrosomic baby?
- EFW of >4500g in diabetic women
- EFW of >5000g in non-diabetic women
How should vaginal delivery of a macrosomic infant take place?
In a controlled fashion, with immediate access to anaesthetic staff and neonatal resuscitation team
What are the maternal risks of LGA?
- Labour problems
- Genital tract lacerations
- Post-partum haemorrhage
- Uterine rupture
- Higher incidence of C-section delivery
What labour problems are at increased risk in LGA?
- Obstructed labour
- Instrumental delivery
Why is there an increased risk of post-partum haemorrhage with LGA?
Increased risk of uterine atony
What are the fetal risks of LGA?
- Increased risk of intrauterine and neonatal death
- Neonatal hypoglycaemia
- Birth injury
- Talipes
Give 2 birth injuries that LGA babies have higher risk of
- Shoulder dystocia
- Brachial plexus palsy
