Very low birth weight births at non-NICU hospitals: the role of sociodemographic, perinatal, and geographic factors.

PURPOSE: The purpose of this study was to assess the extent of variation in the percentage of very low birth weight (VLBW) infants born at perinatal Level 1 hospitals (no Neonatal Intensive Care Unit [NICU]) across California's nine geographic Perinatal regions. The role of sociodemographic, perinatal, and geographic factors was also assessed.

METHODS: Multivariate analysis of California birth certificate files between 1989 and 1993, for 24,094 live-born infants weighing between 500 and 1499 gm, was conducted to identify factors associated with delivery at a Level 1 hospital. Analyses specific for race and ethnicity were also conducted for Hispanic, African American, and white cohorts.

RESULTS: In the 5-year study period, 1989 through 1993, 10.5% (24,094) of all live-born VLBW infants were delivered in Level 1 hospitals. Significant variation across regions was evident, ranging from a regional low of 3.1% to a high of 24.3%. After controlling for multiple factors, the odds of delivering at a Level 1 hospital were decreased for African Americans and South East Asians and increased in Hispanic women as compared with white non-Hispanic women. For all women, less then adequate prenatal care, living in a 50% to 75% urban zip code, and living greater then 25 miles from the nearest NICU significantly increased the odds of VLBW delivery at a Level 1 hospital. For Hispanics, teen pregnancy and having two or more prior infant deaths increased the odds, whereas Medi-Cal as the payer source for delivery and two or more pregnancy complications decreased the odds of a Level 1 VLBW delivery. After taking these factors into account, when compared with Los Angeles, the odds of inappropriate delivery site ranged from 0.37 to 2.75 across California's nine geographic perinatal regions. Of this variation, 78% could be accounted for by the percentage of total births that delivered at a region's Level 1 hospitals.

CONCLUSION: The overall state average of 10.5% deliveries of VLBW at Level 1 hospitals, although close to the 10% national objective for the year 2000, did not indicate the wide variation seen across California's nine geographic regions. Risk-adjusted regional differences in the likelihood of inappropriate delivery site for the high-risk VLBW infants suggest that reaching the Healthy People 2000 objective will require further strengthening of California's perinatal regional networks, especially in those regions where a high percentage of total births deliver at Level 1 hospitals.