Fetal growth standards in gastroschisis: Reference values for ultrasound measurements

Interval growth across gestation in pregnancies with fetal gastroschisis

BACKGROUND

Gastroschisis is often complicated by fetal growth restriction, preterm delivery, and prolonged neonatal hospitalization. Prenatal management and delivery decisions are often based on estimated fetal weight and interval growth; however, appropriate interval growth from week to week across gestation for these fetuses is poorly understood.

OBJECTIVE

This study aimed to determine the median increase in overall estimated fetal weight and individual biometric measurements across each week of gestation in pregnancies with fetal gastroschisis and to assess whether lower in utero fetal weight gain is predictive of postnatal growth or adverse neonatal outcomes.

STUDY DESIGN

This was a retrospective cohort study of pregnancies with gastroschisis evaluated at 5 institutions of the University of California Fetal-Maternal Consortium from December 2014 to December 2019. The inclusion criteria were prenatally diagnosed gastroschisis with at least 1 ultrasound performed at a University of California Fetal-Maternal Consortium institution. Estimated fetal weight and individual biometric measurements were recorded for each ultrasound performed at a University of California Fetal-Maternal Consortium institution from the time of gastroschisis diagnosis to delivery. Median estimated fetal weight and biometric measurements were calculated for each gestational age in 1-week increments. Neonatal outcomes collected were birthweight, length of stay, complications of gastroschisis (bowel atresia, bowel stricture, ischemic bowel before closure, or severe pulmonary hypoplasia), and growth failure at discharge.

RESULTS

We identified 95 pregnancies with fetal gastroschisis who, in aggregate, had 360 growth ultrasounds at a University of California Fetal-Maternal Consortium institution. The median interval growth was 130 g/wk. The median estimated fetal weight and abdominal circumference in fetal gastroschisis cases were approximately the tenth percentile on the Hadlock growth curve across gestation. Moreover, the median biparietal diameter, head circumference, and femur length measurements remained below the 50th percentile on the Hadlock growth curve across gestation. The median birthweight for neonates with less than the median weekly prenatal weight gain was less than for those with greater than the median weekly prenatal weight gain (2185 g vs 2780 g; P<.01). There was no difference in prenatal weight gain trajectory when comparing neonates who had or did not have bowel complications of gastroschisis.

CONCLUSION

In this multicenter cohort of pregnancies with fetal gastroschisis, the median interval growth was 130 g/wk, and overall, in utero growth closely followed the tenth percentile on the Hadlock curve. Poor prenatal growth in cases of fetal gastroschisis correlates with lower neonatal weights but did not predict a more complicated course.