Fetal growth standards in gastroschisis: Reference values for ultrasound measurements.

OBJECTIVES: The objectives of this study were to create growth curves based on ultrasonography biometric parameters of fetuses with gastroschisis, comparing them with normal growth standards, and to analyze umbilical artery (UA) Doppler velocimetry patterns.

METHODS: A cohort study of 72 fetuses with gastroschisis, at gestational ages between 14 and 39 weeks was designed. Mean and standard deviation were calculated, with the 5th, 10th, 50th, 90th, and 95th centiles being established for biometric parameters according to gestational age. Curves were obtained, comparing with normal reference via the Mann-Whitney test. UA Doppler velocimetry patterns were obtained.

RESULTS: A total of 434 examinations were performed, and centiles were established for biparietal diameter, head circumference, abdominal circumference, femur length, and estimated fetal weight. A significant difference was observed between the gastroschisis measurements when compared to control, with all curves shifted downwards. Abdominal circumference was the parameter presenting the largest difference. Estimated fetal weight was also lower, with mean difference of 256.3 ± 166.8 g for the 50th centile (P < .0001). UA Doppler velocimetry was normal in 97.5%.

CONCLUSIONS: Fetuses with gastroschisis show symmetrical growth deficits in the second and third trimesters, with normal UA Doppler velocimetry. These results reinforce the hypothesis that they are constitutionally smaller, yet not restricted because of placental insufficiency.