Omphalocele and gastroschisis: an 18-year review study.

PURPOSE: Using data from a single University Genetics Division practice, the authors sought to determine if gastroschisis is increasing in occurrence compared to omphalocele. Associated abnormalities were also examined. In addition, prenatal exposure to teratogens and other parameters were compared.
METHODS: All fetal and infant cases of omphalocele and gastroschisis seen in the University of South Florida Division of Genetics between January 2, 1982 and December 31, 1999 were retrieved through the database and analyzed through chart review.
RESULTS: There were 127 cases of omphalocele and 121 cases of gastroschisis. Ninety-three of the 127 probands with omphalocele had karyotype determinations and 20% were abnormal; for gastroschisis, 37 had cytogenetic studies and none had chromosomal anomalies. Seventy-six percent of the probands with omphalocele had associated abnormalities; twenty-three percent of the probands with gastroschisis, none of which were syndromic, had associated anomalies. The prematurity rate for omphalocele was 42% and mortality was 22%; for gastroschisis, the figures were 57% and 9%, respectively. There were no significant differences in teratogen exposure between the two groups. Familial cases of both defects occurred in < 4%, and the prevalence of dizygous twinning was increased in both groups. Mean maternal age was 21.8 years for the gastroschisis group, 27.2 years for the omphalocele group.
CONCLUSIONS: In this study, the number of cases of omphalocele and gastroschisis were similar, compared to the expected 3:2 ratio, suggesting an increase in the occurrence of gastroschisis. Cases with omphalocele had more syndromic and nonsyndromic anomalies, more chromosomal anomalies, a higher mortality rate, and older mothers.