July 1994

Increased Risk of Small Intestinal Atresia Among Twins in the United States

Author Affiliations

From the Division of Birth Defects and Developmental Disabilities, National Center for Environmental Health, Centers for Disease Control and Prevention, Public Health Service, US Department of Health and Human Services, Atlanta, Ga.

Arch Pediatr Adolesc Med. 1994;148(7):733-739. doi:10.1001/archpedi.1994.02170070071014

Objective:  To compare the prevalence of small intestinal atresia among twins and singletons in the United States.

Design:  Descriptive analysis.

Measurements:  The McDonnell Douglas Health Information System (MDHIS), a national registry of newborn diagnoses, 1982 through 1988; and the Metropolitan Atlanta Congenital Defects Program (MACDP), a registry of defects among infants in Atlanta, 1968 through 1989.

Patients:  Live-born infants with small intestinal atresia.

Interventions:  None.

Main Results:  In both systems, the rate of small intestinal atresia was higher among twins than singletons (MDHIS: 5.5 per 10 000 vs 2.0, relative risk [RR] = 2.8, 95% confidence interval [CI] = 1.9 to 4.0; MACDP: 7.3 vs 2.5, RR = 2.9, 95% CI = 1.5 to 5.7). The increase was more notable among same-sex twins than opposite-sex twins, suggesting an increase among monozygotic twins. It was also more notable among twins with jejunoileal atresia than those with duodenal atresia, suggesting a vascular cause in many cases.

Conclusion:  Twins have a higher rate of small intestinal atresia than singletons, possibly due to vascular disruption in monozygotic twins.(Arch Pediatr Adolesc Med. 1994;148:733-739)