Fetal omphalocele and gastroschisis: pitfalls in sonographic diagnosis.

The prenatal sonographic findings in 10 infants with omphalocele or gastroschisis diagnosed either by sonogram or by physical examination at birth are reviewed. There were six true-positive diagnoses, as well as two false-positive and two false-negative diagnoses by sonography. The false-positive cases resulted from confusion of umbilical cord with extruded bowel (1 case) and oligohydramnios coupled with improper scanning technique (1 case). The false-negative cases resulted from poor documentation of fetal anatomy (1 case) and confusion of extruded bowel with umbilical cord (1 case). These pitfalls may be avoided by using optimal scanning technique with documentation of fetal anatomy and pulsed Doppler sonography.