Table 1.

Odds of preterm birth from multiple logistic regression models (method multiple logistic regression model )

	MEHP	MBP
	Odds ratio (95% confidence interval)	Odds ratio (95% confidence interval)
Visit 1	1.08 (0.85, 1.38)	0.84 (0.56, 1.25)
Visit 2	0.93 (0.70, 1.24)	1.17 (0.83, 1.66)
Visit 3	1.33 (0.99, 1.79)	1.49 (0.98, 2.27)
Visit 4	1.11 (0.83, 1.48)	1.17 (0.80, 1.72)

N = 282 for MEHP and MBP models. 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.