THE RISKS CONFRONTING TWINS - A NATIONAL PERSPECTIVE

OBJECTIVES: Our objectives were twofold: (1) to report the relative ri sks and population-attributable risks of twins compared with singleton s for several adverse pregnancy outcomes and (2) to describe the assoc iation between having been of low or very low birth weight and death i n the neonatal, postneonatal, and infant periods for twins compared wi th singletons. STUDY DESIGN: We performed population-based analysis of all live births and infant deaths from 1985 to 1986 birth cohorts, as reported in the U.S. Linked Birth/infant Death Data Sets. RESULTS: Wi th singletons as the referent group, twins of all races had relative r isks for very low birth weight, low birth weight, and neonatal, postne onatal, and infant death of 9.97, 8.61, 7.06, 2.75, and 5.43, respecti vely. Although twins make up only 2.09% of live births, the population -attributable risks of twins (the proportion of the population's adver se outcome associated with being a twin) for very low birth weight, lo w birth weight, and neonatal, postneonatal, and infant death was 15.8% , 13.7%, 11.2%, 3.4%, and 8.4%, respectively.CONCLUSIONS: These popula tion-based data show that although twins are relatively infrequent the y account for a disproportionately large share of adverse pregnancy ou tcomes. Given the relative ease with which twins can be identified ear ly in the course of pregnancy, development and testing of intervention s to postpone preterm delivery in twin pregnancy should become a natio nal public health priority.