Consumption of low-moderate level arsenic contaminated water does not increase spontaneous pregnancy loss: a case control study

Table 4 Covariate-adjusted odds ratios for spontaneous pregnancy loss in association with continuous iAs exposure, by cigarette smoking (n = 300)

Product-term entered	Risk/Protector factor and iAs exposure	Cigarette smoking^a		Prenatal vitamin use^b
Product-term entered	Risk/Protector factor and iAs exposure	OR^c	95% CI	OR^c	95% CI
Average iAs (μg/L)^d × Risk/Protector factor	No
	0.0 μg/L iAs	1.00	Reference	1.00	Reference
	10.0 μg/L iAs	0.70	0.44, 1.09	1.12	0.72, 1.72
	Yes
	0.0 μg/L iAs	0.97	0.51, 1.83	0.50	0.27, 0.90
	10.0 μg/L iAs	1.75	0.75, 4.10	0.30	0.13, 0.67
	P-value for interaction	0.057		0.159
Peak iAs (μg/L)^e × Risk/Protector factor	No
	0.0 μg/L iAs	1.00	Reference	1.00	Reference
	10.0 μg/L iAs	0.73	0.52, 1.04	1.07	0.71, 1.63
	Yes
	0.0 μg/L iAs	0.97	0.51, 1.82	0.47	0.26, 0.86
	10.0 μg/L iAs	1.69	0.76, 3.74	0.35	0.18, 0.70
	P-value for interaction	0.053		0.298
Daily iAs (μg/day)^f × Risk/Protector factor	No
	0.0 μg/day iAs	1.00	Reference	1.00	Reference
	10.0 μg/day iAs	0.78	0.58, 1.06	1.04	0.80, 1.34
	Yes
	0.0 μg/day iAs	0.94	0.49, 1.78	0.54	0.30, 0.98
	10.0 μg/day iAs	1.41	0.73, 2.74	0.31	0.15, 0.63
	P-value for interaction	0.048		0.085

^an=2 influential observations excluded;
^bn=4 influential observations excluded;
^cLogistic regression models incorporating continuous exposure expressed as a 10 units increase, conditioned on gestational age (weeks), and including product-term, adjusted for maternal age (years), cigarette smoking during pregnancy (average daily cigarettes), education (<High School, High School, University) and prenatal vitamin use (no/yes); ^dmean iAs level measured in up to two residential drinking water sources; ^ethe highest iAs level measured in up to two residential drinking water sources; ^fproduct of ‘daily water consumption’ multiplied by ‘average iAs.’
iAs, inorganic arsenic; CI, confidence interval; OR, odds ratio.

ISSN: 1476-069X