Risk factors for XXXX in twin gestations in the state of South Carolina.

@entity1 @entity154 @entity204
OBJECTIVE: The aim of the study was to describe risk factors for @entity204 among twins born in South Carolina. STUDY DESIGN: South Carolina publicly accessible live birth and @entity1 death cohort files for live-born twins >500 g were reviewed for the years 1988 through 1993. @entity1 with @entity154 were deleted from the cohort before analysis. Risk factors for @entity204 were determined for the entire cohort and for the birth weight categories of 500 to 999 g, 1000 to 1499 g, 1500 to 2499 g, and >/=2500 g. Statistical comparisons were performed with the Mantel-Haenszel chi2 test and multivariate logistic regression. RESULTS: Of 7833 live-born twins, 263 (3.4%) died during the neonatal period. The mean birth weight was 2357 +/- 650 g (range 500-5358 g) at a mean gestational age of 35.7 +/- 3.5 weeks. Overall neonatal mortality rates were significantly increased (P <.001) for twins whose mothers were nonwhite (4.2 vs 2.8%), were <20 years old (6.0 vs 3.2%), or received no prenatal care (14.7 vs 3.1%). After we controlled for population characteristics with multivariate techniques, analysis revealed birth weight <2500 g and residence in the most populous urban areas to be associated with increased neonatal mortality rates. After stratification into birth weight categories, race was no longer a significant variable; in fact, nonwhite twins had a survival advantage at birth weights <1500 g, but this was not significant. Maternal age <20 years was associated with a higher neonatal mortality rate for @entity1 with birth weights between 1500 and 2499 g. Absence of prenatal care significantly increased the neonatal mortality rate for twins >/=1500 g but not for those who were smaller. For @entity1 weighing 500 to 999 g neonatal mortality rates were significantly lower at hospitals with >/=2000 deliveries/y than at hospitals with lower delivery volumes (P =.005). CONCLUSIONS: Although the overall neonatal mortality rate for twins continues to improve, increased rates are still seen among blacks, teenagers, and @entity1 who receive no prenatal care. Twins between 500 and 999 g have significantly reduced neonatal mortality rates when delivered at hospitals with a high obstetric volume.
