Sonographic assessment of the extra-abdominal fetal small bowel in gastroschisis: a retrospective longitudinal study in relation to prenatal complications.

OBJECTIVE: An explorative retrospective study following a case-series of fetuses with isolated gastroschisis, to evaluate if small-bowel dilatation may be indicative for emerging obstetric complications. The secondary aim was to establish preliminary normative curves for the external diameter and wall thickness of eventerated fetal small bowel in gastroschisis during the second and third trimester of pregnancy.

METHODS AND MATERIALS: Fourteen fetuses with isolated gastroschisis were followed at a single center. Repeated ultrasound examinations for fetal surveillance with measurement of fetal small-bowel diameter and wall thickness over the course of pregnancy until delivery were performed.

RESULTS: Longitudinal data analysis showed significantly increasing bowel diameter and wall thickness of eventerated small bowel with advancing gestation. Dilatation of small bowel more than 25 mm in the third trimester of pregnancy was associated with an increased risk of short-term prenatal complications as fetal distress or intrauterine fetal death (PPV 100%; 95% CI: 29.2-100%, NPV 100%; 95% CI: 71.5-100%).

CONCLUSIONS: Dilatation of the extra-abdominal fetal small bowel in the third trimester may allow identifying fetuses with increased risk of fetal distress requiring closer monitoring of fetal well-being or delivery in a short interval to prevent impending fetal death.