Fetal Growth Pattern and Prediction of Low Birth Weight in Gastroschisis.

OBJECTIVES

To examine growth patterns and predictions of low birth weight in gastroschisis fetuses.

METHODS

This is a retrospective study of isolated fetal gastroschisis before week 24. Ultrasound fetal biometric parameters - head circumference (HC), abdominal circumference (AC), femur length, HC/AC ratio and estimated fetal weight (EFW)--were plotted against normal growth charts. The percentage difference in mean values between normal and gastroschisis fetuses was determined. The growth deficit for each ultrasound parameter was calculated for the fetuses with 1 examination in each designated period (period I: weeks 20-25(+6); period II: weeks 26-31(+6); period III: from week 32 until term). For low birth weight prediction, measurements below the 10th percentile in periods I and II were tested.

RESULTS

Seventy pregnancies were examined. For all fetal parameters, the mean measurements were lower in fetuses with gastroschisis (p < 0.005). The EFW revealed an increased growth deficit between the periods (p = 0.030). HC was predictive of low birth weight in period II (OR = 6.07; sensitivity = 70.8%; specificity = 71.4%).

CONCLUSIONS

Fetuses with gastroschisis present a reduced growth pattern, and it appears that no growth recovery occurs after the growth restriction has been established. Between week 26 and week 31(+6), an HC measurement below the 10th percentile is associated with an increased risk of low birth weight.