Background: We examined pregnancy outcomes in New York City (NYC) and upstate New York after the September 11, 2001 World Trade Center disaster.
Methods: Using birth certificate data for NY residents (n = 1,660,401 births), we estimated risk of low birthweight (LBW: <2,500 g) and preterm birth (<37 weeks) one week after September 11th versus three weeks before, and for 10 four-week intervals post-disaster versus these intervals in the two previous years. To corroborate regression results, we used time-series analysis.
Results: One week after September 11th in NYC, we observed an adjusted odds of 1.44 for births <1,500 g (P = 0.07) and 1.67 for births 1,500-1,999 g (P = 0.01), but a decreased odds of 2,000-2,499 g. We found no immediate change in LBW upstate or preterm in either location. In extended analyses, we found, in both locations, increased odds of <1,500-g births around New Year and 33-36 weeks post-disaster and decreased odds of moderate preterm for several weeks post-disaster. Time-series analyses yielded similar findings.
Conclusions: The events of September 11, 2001 in NYC were associated with immediate increases in births <2,000 g, slightly delayed decreased preterm delivery, and delayed increases in LBW among infants exposed periconception or in the first two trimesters. Stress may contribute to observed associations.