Table 5.

Accelerated failure time model (AFT) results on the relationship between gestational age and Ta (n = 473,977) and logistic model results on preterm (n = 473,977) and low birth weight outcomes (n = 453,658).

Outcome and exposure time period	Predicted air temperature (°C)	Closest monitor temperature (°C)
AFT model (gestational period) β (95% CI)
Last trimester	–0.0015 (–0.0026, 0.0005)	0.0037 (0.0037, 0.0038)
Entire pregnancy	–0.0026 (–0.0028, –0.0025)	0.0089 (0.0088, 0.0090)
Preterm births (< 37 weeks) [OR (95% CI)]
Entire pregnancy	1.02 (1.00, 1.05)	1.07 (0.87, 1.27)
Low birth weight (< 2,500 g) [OR (95% CI)]
Entire pregnancy	1.04 (0.96, 1.13)	1.02 (0.45, 2.30)
All models adjusted for predicted air temperature, predicted PM2.5, cumulative traffic density, percent of open spaces, age of mother, chronic conditions of mother or conditions of pregnancy (lung disease, hypertension, gestational diabetes or non-gestational diabetes), parity, previous infant weighing ≥ 4,000 g and sex of infant, sine and cosine (controlling for seasonality), APNCU (as a categorical variable), mother’s race (as a categorical variable), mother’s education (as a categorical variable), and previous preterm occurrences.