Table 3.

Odds ratios for an interquartile range change in urinary GLY and AMPA concentrations during pregnancy and preterm birth.

Analyte	Crudea			Adjustedb
	Preterm [$n$]	Term [$n$]	OR (95% CI)	Preterm [$n$]	Term [$n$]	OR (95% CI)
IQR GLYc
Visits 1 and 3 average	35	103	1.29 (0.79, 2.12)	32	97	1.06 (0.57, 1.96)
Visit 1 ($18\pm 2$ wk)	35	142	1.01 (0.65, 1.55)	32	135	1.11 (0.71, 1.74)
Visit 3 ($26\pm 2$ wk)	53	155	1.38 (1.06, 1.79)	50	148	1.35 (0.99, 1.83)
IQR AMPAd
Visits 1 and 3 average	35	103	1.36 (0.98, 1.89)	32	97	1.28 (0.87, 1.87)
Visit 1 ($18\pm 2$ wk)	35	142	0.89 (0.64, 1.25)	32	135	0.92 (0.67, 1.27)
Visit 3 ($26\pm 2$ wk)	53	155	1.57 (1.22, 2.02)	50	148	1.67 (1.26, 2.20)

Note: AMPA, aminomethylphosphonic acid; BMI, body mass index; CI, confidence interval; GLY, glyphosate; IQR, interquartile range; OR, odds ratio.

^aBiomarkers are adjusted for specific gravity using the formula: ${\text{GA}}_{\text{SG}}=\text{GA}\left[\left(1.019–1\right)/\left(\text{SG}-1\right)\right]$, where ${\text{GA}}_{\text{SG}}$ is the SG-adjusted GLY or AMPA concentration ($\mathrm{\mu }\mathrm{g}/\mathrm{L}$); GA is the observed GLY or AMPA concentration; 1.019 is the population median specific gravity; and SG is the specific gravity of the urine sample.

^bModels are adjusted for maternal age, education, prepregnancy BMI, and smoking.

^cIQRs were calculated based on GLY distribution in controls. IQRs were 0.56, 0.52, and 0.54 for Visit 1, Visit 3, and the Visits 1 and 3 average, respectively.

^dIQRs were calculated based on AMPA distribution in controls. IQRs were 0.27, 0.40, and 0.30 for Visit 1, Visit 3, and the Visits 1 and 3 average, respectively.