Gastroschisis: Prenatal diagnosis and management
Dr Campbell is Assistant Professor, Yale School of Medicine, and Medical Director, Yale Maternal-Fetal Medicine Practice, New Haven, Connecticut.
Dr Copel is Professor, Yale School of Medicine, and Vice Chair, Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University, New Haven, Connecticut.
Neither author has a conflict of interest to report in respect to the content of this article.
A 20-year-old gravida 1 presented for a targeted anatomy ultrasound in the setting of an elevated maternal serum alpha fetoprotein (MSAFP) (7.14 MoM) obtained from routine prenatal screening. Transabdominal ultrasound revealed a full-thickness abdominal wall defect to the right of the umbilical cord insertion with herniation of abdominal contents. Free-floating loops of bowel were seen in the amniotic fluid without evidence of a covering membrane. The patient underwent serial ultrasounds to assess fetal growth and well-being. At 38 weeks’ gestation, fetal testing revealed a biophysical profile (BPP) that was 4/10 (2 points for fluid and fetal breathing). The patient was subsequently admitted to labor and delivery for repeat fetal testing and ultimately induction. She patient proceeded to have an uncomplicated vaginal delivery. At delivery, the lower half of the neonate’s body was placed in a sterile plastic bag to protect the exposed fetal bowel and promptly handed off to the waiting pediatricians. The neonate underwent a successful reduction of gastroschisis with a silastic silo and subsequent bioclosure of the defect and was discharged from the neonatal intensive care unit at 6 weeks of age.
The term gastroschisis is derived from the Greek words “gastro,” meaning stomach, and “schism,” meaning cleft. The condition is described as a full-thickness paraumbilical defect in the abdominal wall.1 In the majority of cases, this defect lies to the right of a normally inserted umbilical cord. Abdominal wall defects are usually small (<4 cm), however, their presence invariably leads to herniation of the fetal mid gut (ileum and jejunum) (Figure 1A). The intestinal loops float freely in the amniotic fluid and, by definition, are not covered by peritoneal membrane (Figure 1B). Additional organs can herniate including the stomach, liver, spleen, and the genitourinary tract, but that is not common.
Fetal assessment with ultrasound after the first trimester reveals free-floating loops of bowel with a “cauliflower-like” appearance in the setting of a normal umbilical cord insertion (Figure 2). Differentiating between gastroschisis and omphalocele is critical. By definition, omphalocele is a ventral wall defect that results in midline herniation of abdominal viscera into the base of the umbilical cord. Prior to the 1950s, gastroschisis was considered a variant of omphalocele. Now, however, the differing pathophysiologies, unique risk factors, and different perinatal outcomes of the 2 conditions are appreciated.