Table 4.

Multivariate logistic regression was used to determine the associations between WHR and the risk of primary and secondary infertility for US women aged 20–45 years, weighted (crude model)

Variable	Primary population (n = 859)		Secondary population (n = 959)
	OR (95% CI)	p value	OR (95% CI)	p value
WHRa	1.05 (0.87–1.26)	0.60	1.99 (1.41–2.80)	<0.001
Binary variable
WHR <0.85	1.00 (reference)		1.00 (reference)
WHR ≥0.85	1.08 (0.79–1.47)	0.61	3.44 (1.86–6.35)	<0.001

Data presented are OR and 95% CI.

WHR, waist-hip ratio; OR, odds ratio; 95% CI, 95% confidence interval.

Crude model: no covariate was adjusted.

^aThe OR was examined by per 0.1-unit increase of WHR.