193: Individualized Growth Assessment in pregnancies complicated by fetal gastroschisis

Abstract

Fetal gastroschisis is associated with IUGR and SGA. Prenatal US may overcall IUGR because the abdominal circumference and associated weight estimations can be underestimated by herniated viscera. Individualized Growth Assessment (IGA) evaluates fetal and neonatal growth based on serial US measurements, thus is different from conventional methods that use population-based curves at fixed time points. Our goal was to assess the potential of IGA for separating normal and pathological growth in gastroschisis cases. Pregnancies with fetal gastroschisis that were managed and delivered at a single academic medical center were analyzed. Cases were classified into four groups by the presence of IUGR and SGA. IUGR was defined as US EFW <10th percentile by Hadlock formula; SGA was defined as birthweight <10th percentile by Fenton curve. Second and third trimester US fetal biometry and neonatal measurements were entered into iGAP software, which calculates fetal and neonatal growth pathology scores based on estimates of growth potential from 2nd trimester growth velocities. Agreement between conventional US methods and IGA was assessed. Of 70 pregnancies with fetal gastroschisis delivered between 2009 and 2016 at a single center, 21 pregnancies with at least four US measurements were included. In the no IUGR/no SGA group (n=12), there was 75% agreement (9/12) between IGA and conventional methods. IGA reported a negative prenatal growth score in three cases, but all showed a normal neonatal growth score. In the yes IUGR/yes SGA group (n=5) there was 100% agreement between IGA and conventional methods in assessing prenatal growth restriction. However, IGA reported a negative neonatal growth score in only two (40%) of the cases. In the yes IUGR/no SGA group (n=3), IGA resulted in a negative prenatal growth score in two (67%) cases, with a normal neonatal growth score in all three cases. In the one no IUGR/yes SGA case, IGA did not identify prenatal or neonatal growth pathology. We present the first study using IGA to evaluate pathological fetal and neonatal growth in gastroschisis cases. While we found general agreement between IGA and conventional US methods, IGA was able to identify normal growth and pathologic growth restriction missed by conventional methods in the prenatal and neonatal periods.