Survival of Texas infants born with trisomies 21, 18, and 13

Trisomies 21, 18, and 13 are the three most common trisomies among infants who survive to 20 weeks gestation or more. Overall information about birth prevalence, natural history, and mortality for all three trisomies is well defined, but information about ethnic-specific rates is limited. Only a few studies have examined mortality rates of trisomies 18 and 13 because so few cases are liveborn and most have very short life spans. This study assessed ethnic-specific population-based survival probabilities among infants for each trisomy. All cases of trisomies 21, 18, and 13 born in Texas between 1999 and 2003 were obtained from the Texas Birth Defects Registry and included 2,260 cases of trisomy 21, 398 cases of trisomy 18, and 213 cases of trisomy 13. Date and cause of death were obtained from the Texas vital statistics records and the National Death Index. Overall, birth prevalence rates (per 10,000 adjusted live births) for the three trisomies were 11.74 (95% CI: 11.25-12.25), 1.34 (95% CI: 1.18-1.52), 0.92 (95% CI: 0.79-1.07), respectively, and are consistent with previously reported rates. There were no differences in survival rates by ethnicity and the median survival for each trisomy was consistent with previous reports. The results of this study provide comprehensive population-based information for survival of infants with trisomies 21, 18, and 13.