Third trimester ultrasound for the prediction of the large for gestational age fetus in low-risk population and evaluation of contingency strategies
Prenatal Diagnosis, 06/26/2012
Pilalis A et al. – Third trimester ultrasound is an effective screening modality for identifying fetal macrosomia. A contingency strategy utilizing first trimester parameters can reduce the need for unnecessary examinations.
Methods- Observational cross–sectional study on 2308 uncomplicated singleton pregnancies examined at 11 to 14 weeks and at 30 to 34 weeks.
- Ultrasound estimated fetal weight (EFW, area under the curve (AUC)=0.83) was the best single predictor of LGA.
- Maternal weight, delta nuchal translucency and EFW were independent predictors for the integrated model, but the latter was not statistically better (AUC=0.84) than using EFW alone.
- The detection rates for LGA were 72.5% and 73.7% for a 25% screen positive rate, by EFW and the third trimester integrated model respectively.



