Epidemiology of abdominal wall defects, Hawaii, 1986-1997

The various types of abdominal wall defects are considered to differ in their etiologies, a hypothesis suggested by differences in their epidemiologies. This study examined the impact of selected demographic factors on abdominal wall defects (omphalocele, gastroschisis, and body stalk anomaly) included in a birth defects registry in Hawaii from 1986-1997. The total prevalence for the various defects were: omphalocele (2.76 per 10,000 births, 95% confidence interval (CI), 2.14-3.50), gastroschisis (3.01, 95% CI, 2. 36-3.77), and body stalk anomalies (0.32, 95% CI, 0.14-0.64). The prevalence increased over the 12-year period for both omphalocele (P = 0.052) and gastroschisis (P = 0.008). Women less than age 20 were at increased risk for a gastroschisis-affected pregnancy, while those age 40 and over were disproportionately more likely to have an omphalocele-affected pregnancy. Pacific Islanders had the lowest risk for omphalocele, whereas Far East Asians were least likely to have gastroschisis. Omphalocele rates were lower outside metropolitan Honolulu, while place of residence did not significantly impact gastroschisis risk. The 1-year survival rate was higher for gastroschisis than for omphalocele (88.5% and 70.7%, respectively), while none of the infants with body stalk anomalies was live-born. The results of this study tend to support the hypothesis of differing etiologies for the studied abdominal wall defects.