Impact of race and ethnicity on the outcome of preterm infants below 32 weeks gestation.

OBJECTIVES

To determine the impact of race/ethnicity on mortality and morbidity such as intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), bronchopulmonary dysplasia (BPD) and bacteriologically confirmed sepsis, assisted ventilation, surfactant administration, intrauterine growth retardation (IUGR), and patent ductus arteriosus (PDA) among very prematurely delivered infants.

STUDY DESIGN

Retrospective study of a cohort of 1006 preterm neonates with gestational age ranging from 22 to 32 weeks discharged from the Neonatal Intensive Care Unit (NICU) between 1998 and 2001. Subgroup analysis according to gestational age (GA) (22 to 24, 25 to 28, and 29 to 32 weeks) and plurality (singleton and multiple) was performed using the chi(2) test and an analysis of variance.

RESULTS

Of the 1006 infants, 54.3% were white, 21.7% black, 13.7% Hispanic, and 10.3% were classified as Other. Multiple births among white infants were approximately twice that in (42.4%) black infants (22.1%), and was also significantly higher than in the Hispanic (28.3%) and other race/ethnic groups (25.2%). Overall, a higher proportion of black infants were born with a GA <or=28 weeks (n=115, 55.3%) than white (n=201, 37.1%) and Hispanic (n=53, 38.4%), p<0.05. Therefore, black neonates had a lower GA (27.9+/-2.9 weeks) and birth weight (1170+/-463 g) as compared to white (p<0.0002) and Hispanic infants (p<0.0001). There was no significant impact of race/ethnicity on the mean gestational age in any of the gestational age categories. Infant mortality and morbidity in each gestational age category by race/ethnicity were comparable. The multiple birth black infants were seen to have a lower gestational age and birth weight as compared to singleton black as well as to white, Hispanic and other race/ethnic groups. However, this did not influence morbidity and mortality in multiple birth black neonates. The result of this study showed that the level of prematurity and not plurality predominantly influences the rate of infant mortality and morbidity in each race/ethnic category.

CONCLUSIONS

The reduction in gestational age and birth weight in black neonates is not associated with an increased risk of infant mortality and morbidity. In general, the outcomes of black singleton and multiple pregnancies were comparable with those of white, Hispanic and other race/ethnic groups.