Registry analysis supports different mechanisms for gastroschisis and omphalocele within shared developmental fields

Nine thousand two hundred eighty abnormalities associated with 2,943 abdominal wall defects (AWD) encoded from 1999 to 2008 by the Texas Birth Defects Registry (TBDR) were classified and analyzed for mechanism, beginning with 1,831 gastroschisis cases, 774 (41%) with 2,368 associated anomalies (AA) and 814 of omphalocele, 727 (89%) with 4,092 AA. Typical AA profiles for Trisomy 18 (23% of omphalocele cases) and Beckwith-Wiedemann syndrome (15%) validated registry AA descriptors, chromosome disorders surprisingly accounting for 24% of known conditions with gastroschisis followed by expected amniotic band (ADAM) complex (23%) and amyoplasia/arthrogryposis (16%). Separation of known diagnoses, fetal-stillbirth cases, and transitional or secondary AA left 330 cases of gastroschisis with 594 AA (452 major, 142 minor) and 295 cases of omphalocele with 956 AA (683 major, 273 minor). Anomalies suggestive of vascular origin (intestinal atresias, amyoplasia, bands) were more frequent with gastroschisis and those of defective lateral folding (exstrophies, limb-body wall defects) with omphalocele. Most AA favoring omphalocele had parallel frequencies with gastroschisis, whether by system/region-for example, cardiac AA (10% of cases), contractures (4.7%), limb (3.7%), CNS (3.2%) for gastroschisis versus cardiac (35%), contractures (14%), digestive-excretory-trunk-axial (all ∼11%), CNS (9.9%) for omphalocele-or for particular minor/major AA-for example, micrognathia (0.72% versus 3.3%), spina bifida (0.59% versus 3.9%), anal atresia (0.73% versus 6.4%), two-vessel cord (0.22% versus 5.6%). Similar frequencies of many AA reflective of early patterning support common AWD origin within early developmental fields and reinforce the use of large birth defect numbers from suitably qualified registries to define anomaly mechanism as well as prevalence.