Large for dates Flashcards
What is a large for dates pregnancy (LGA)?
Term to identify macrosomic babies (≥4kg or ≥4.5kg – the definition varies) -> 10% of pregnancies
What tools are used to diagnose LGA?
Prenatally, 3 tools used to diagnose large for age
o 1st -> Symphysis-fundal height (SFH) -> >90th/95th centile for gestational age -> foetal biometry
o 2nd -> Abdominal Circumference (AC) -> >90th/95th centile for gestational age
o 2nd -> Estimated foetal weight (EFW) -> >90th/95th centile for gestational age
What are the risk factors for LGA?
High BMI Foetal macrosomia (>4kg in a term infant) Gestational or DM Syndromes: Beckwith-Wiedemann, Simpson-Golabi-Behemel, Soto’s syndrome Molar pregnancy Polyhydramnios Multiparity Advanced maternal age
What are the S/S for LGA?
o On inspection -> excessive distension for gestational age
o Abdomen -> increased SFH, increased abdominal circumference
What Ix do you do for LGA?
o OGTT – for gestational diabetes
o Bloods – serum βHCG
o USS – liquor volume, biometry
o Genetic testing
What is the management of LGA?
o Detected at 18-21 weeks -> repeat scan
o Detected at 24-36 weeks -> if acceleration of growth, arrange USS for foetal biometry
§ If follows same path (no drop/rise growth), then reassure this is normal, arrange another routine scan
§ Offer OGTT (gestational diabetes)
o Detected at 36-40 weeks -> if SFH is >90th centile on routine measurements -> USS for foetal biometry
§ If EFW and AC on USS are >95th centile, return to routine care
§ Perform OGTT (gestational diabetes)
§ Care in labour + postnatally as per gestational diabetes dx at earlier gestation
o Need to plan delivery and discuss risk of shoulder dystocia, nerve injuries, prolonged labour -> offer CS
What are the complications of LGA?
o Shoulder dystocia
o Hypoglycaemia in GDM
o Respiratory distress syndrome – combination of GDM, need to deliver earlier
o Intrauterine deformations – metatarsus adductus (foot bends inwards), hip subluxation
o Increased mortality
o Perineal tear
o Prognosis -> early planning/care à no difference in outcomes for LGA compared to normal
