Table 4.

Possible risk factors for spontaneous abortion: results of logistic regression analysis

	Selected variable	Odds ratio	95% Confidence interval	p value
Model 1a	Age	1.194	1.052–1.354	0.006
Model 1 + lead	Age	1.212	1.059–1.389	0.005
	Pb	1.008	0.998–1.019	0.130
Model 1 + cadmium	Age	1.217	1.061–1.396	0.005
	Cd	1.690	0.595–4.797	0.325
Model 1 + antimony	Age	1.254	1.078–1.459	0.003
	Sb	1.652	1.081–2.525	0.020
Model 1 + nickel	Age	1.166	1.003–1.354	0.045
	Ni	1.005	1.000–1.011	0.044

^aVariables were selected by forward stepwise method: spontaneous abortion (=1) and non-abortion (= 0) as dependent variable; maternal age, primipara, and previous abortion as independent variables