Table 6.

Adjusted^a odds ratios (aOR) and 95% confidence intervals (CIs) comparing each score (number of exposures above the highest quartile) compared to those without having a high level any exposure for births in four counties in San Joaquin Valley, 2000–2006 (N=247,487).

Gestational age in weeks	Score	First Trimester			Second Trimester			Third Trimester
		aOR	95% CIs		aOR	95% CIs		aOR	95% CIs
34–36	0	1.00	–	–	1.00	–	–	1.00	–	–
	1	1.06	1.01	1.10	1.06	1.02	1.11	1.03	0.99	1.08
	2	1.09	1.04	1.15	1.07	1.01	1.13	1.07	1.01	1.12
	3	1.04	0.98	1.10	1.10	1.04	1.16	1.07	1.02	1.13
	4	1.07	1.02	1.13	1.16	1.10	1.22	0.96	0.90	1.02
	5	1.10	1.01	1.19	1.07	0.98	1.16	0.99	0.90	1.09
32–33	0	1.00	–	–	1.00	–	–	1.00	–	–
	1	1.07	0.97	1.19	1.05	0.95	1.16	1.18	1.07	1.31
	2	1.17	1.03	1.32	1.27	1.12	1.43	1.25	1.10	1.41
	3	0.98	0.86	1.12	1.13	0.99	1.29	1.22	1.07	1.39
	4	0.99	0.87	1.13	1.25	1.10	1.42	1.10	0.96	1.26
	5	1.13	0.94	1.37	1.13	0.92	1.38	1.20	0.97	1.47
28–31	0	1.00	–	–	1.00	–	–	1.00	–	–
	1	1.15	1.01	1.31	1.09	0.95	1.24	1.14	0.99	1.30
	2	1.24	1.06	1.45	1.40	1.19	1.64	1.20	1.02	1.42
	3	1.02	0.87	1.21	1.24	1.05	1.47	1.46	1.25	1.72
	4	1.05	0.89	1.24	1.58	1.35	1.84	1.09	0.91	1.31
	5	1.08	0.84	1.38	1.57	1.24	1.98	0.93	0.69	1.26
24–27	0	1.00	–	–	1.00	–	–	NC
	1	1.45	1.18	1.78	1.17	0.93	1.46
	2	1.24	0.96	1.62	1.54	1.17	2.01
	3	1.04	0.79	1.37	1.54	1.17	2.03
	4	1.05	0.80	1.38	1.83	1.41	2.38
	5	0.62	0.38	1.02	3.29	2.37	4.55
20–23	0	1.00	–	–	1.00	–	–	NC
	1	1.31	1.00	1.72	1.23	0.86	1.76
	2	0.77	0.52	1.15	1.55	1.01	2.38
	3	0.50	0.32	0.79	1.65	1.08	2.53
	4	0.83	0.57	1.21	2.82	1.94	4.10
	5	0.63	0.33	1.20	4.05	2.51	6.54

Abbreviations: OR, odds ratio; CI, confidence interval; NC, not calculated

^aAdjusted for maternal age, education, race, infant birth weight, prenatal care initiation in first trimester, Medi-Cal payment of birth costs

^bCut-offs for highest quartile of exposure: CO 0.60 ppm; NO₂ 19.49 ppb; PM₁₀ 42.77 μg/m³; PM_2.5 20.75 μg/m³