Gastroschisis is an uncommon abdominal wall defect, with the incidence rate of 0.3-1 in 10,000 births [1
]. It is rare when occurring to the left of the umbilical cord. Only a handful of similar cases have been reported [2
]. Most of the patients recovered very well after surgery. One patient developed respiratory difficulty and died 5 hrs later [8
]. One fetus underwent autopsy after termination of pregnancy at 24 weeks of gestation following the prenatal diagnosis of bilateral multicystic dysplastic kidneys with severe oligohydramnios [6
]. However, none of these studies evaluated the placenta or reported on the findings of an autopsy after live birth.
In the current case, the patient required intubation immediately after birth due to respiratory distress. Prenatal ultrasound examinations raised the suspicion of pulmonary hypoplasia, which was confirmed on autopsy. The findings of this case and previously reported cases suggest a correlation between the size of gastroschisis and the degree of pulmonary insufficiency. Ameh et al. reported that their patient developed respiratory difficulty after the 8 X 6 cm gastroschisis was repaired [8
]. Further, other studies concluded that larger abdominal wall defects increased the incidence of respiratory insufficiency [17
]. Low intra-abdominal pressure in utero may result in an excessively narrow lower thoracic cage, which limits the development of fetal lungs [1
Among the reported cases, evisceration of the stomach, small and large intestine is common, and evisceration of the liver, kidney, urinary bladder and ovary have all been reported [6
Some of the previously reported cases of left sided gastroschisis were not complicated by other abnormalities [2
]. However, one case was complicated with situs inver-tus [9
]. Another case showed pubic diastasis, bifid clitoris, double vagina, anteriorly placed anus, atrial septal defect, and patent ductus arteriosus [10
]. Jejunal atresia and microcolon, cerebral arterio-venous malformation, macrocephaly and stenosis of superior vena cava have also been reported [5
]. In our case, the patient had pulmonary hypoplasia, scoliosis, ventricular septal defect and absence of the gall bladder. These diverse findings suggest that an unidentified syndrome is unlikely; rather, de novo mutations or in utero deformations possibly occurred in order to create these abnormal phenotypes. We suspect that the scoliosis and pulmonary hypoplasia were deformations of the fetus due to the abnormal displacement of organs outside the body cavity.
The pathogenesis of gastroschisis remains controversial, although multiple mechanisms have been proposed [1
]. It has been hypothesized that involution of the right umbilical vein, which normally occurs during embryogenesis, results in decreased viability of the surrounding mesenchyma. Because this mesenchyme is part of the body wall, death of its cells could result in a weakness in the region, allowing the internal organs to herniate. Regression of the left umbilical vein or left-sided omphalomesenteric artery might lead to a left sided gastroschisis [18
]. However, the actual molecular mechanism underlying gastroschisis remains unclear.
It is important to differentiate gastroschisis from omphalocele. Gastroschisis is an abdominal wall defect which usually occurs to the right of the umbilicus, and, rarely, to the left of the umbilicus as in our case. A portion of the medial wall of the defect usually includes the umbilical cord. Omphalocele is a defect in the ventral abdominal wall wherein there is absence of abdominal muscles, fascia, and skin at or surrounding the junction of the umbilical cord with the abdomen. The area of omphalocele is covered by a membrane composed of amnion externally and parietal peritoneum internally, with mesenchymal connective tissue between. Microscopically, vacuolated amnion is specific for gastroschisis, and does not occur in the presence of omphalocele [19
]. Gastroschisis results most likely from a vascular defect. Omphalocele is due to the persistence of the body stalk in the region normally occupied by the somatopleure and is often associated with a chromosomal anomaly. In our case, the position of the defect, the lack of covering membrane, and the placental pathology confirm that this is, indeed, a case of left sided gastroschisis. The absence of situs inversus rules out abnormal situs as the cause of the defect on the left rather than right abdomen. Moreover, the intact amnion on the placental surface exclude the possibility of early amnion rupture.