Table 3.

Odds of preterm birth from parallel cross-sectional logistic regression models (Method Parallel cross-sectional logistic regression models )

		MEHP	MBP
	N	Odds ratio 95% confidence interval	Odds ratio 95% confidence interval
Visit 1	456	1.10 (0.93, 1.30)	1.19 (0.95, 1.48)
Visit 2	407	1.12 (0.93, 1.35)	1.15 (0.91, 1.46)
Visit 3	392	1.17 (0.96, 1.43)	1.23 (0.97, 1.55)
Visit 4	322	1.11 (0.86, 1.43)	1.34 (0.98, 1.83)

Odds ratios in association with ln-unit increase in urinary phthalate metabolite concentration at each study visit. Models adjusted for maternal age at visit 1, race/ethnicity, health insurance provider, education level, BMI at visit 1, and urinary specific gravity and time of day of sample collection at each study visit.