Table 2. Association between waist circumference (cm) and female infertility.
| Model 1 OR (95%CI) | Model 2 OR (95%CI) | Model 3 OR (95%CI) | Model 4 OR (95%CI) | |
|---|---|---|---|---|
| WC (cm) | 1.02 (1.02,1.03)*** | 1.02 (1.01,1.03)*** | 1.04 (1.02, 1.06)*** | 1.03 (1.01, 1.06)** |
| Quintiles of WC (cm) | ||||
| Q1 (56.4–77.8) | Reference | Reference | Reference | Reference |
| Q2 (77.9–86.4) | 1.83 (1.08, 3.11)* | 1.41 (0.83, 2.38) | 1.41 (0.84,2.37) | 1.33 (0.77, 2.29) |
| Q3 (86.5–96.0) | 2.21 (1.31, 3.72)** | 1.63 (0.94, 2.84) | 1.64 (0.91, 2.94) | 1.50 (0.81, 2.77) |
| Q4 (96.1–109.2) | 2.67 (1.59, 4.47)*** | 1.82 (1.07, 3.09)* | 1.82 (1.06, 3.13)* | 1.66 (0.95, 2.90) |
| Q5 (109.3–172.5) | 4.46 (2.75, 7.24)*** | 3.15(1.87, 5.32)*** | 3.16 (1.61, 6.22)** | 2.64 (1.31, 5.30)* |
| P for trend | <0.0001 | 0.0003 | 0.009 | 0.0375 |
| Stratified by BMI (kg/m 2 ) | ||||
| BMI≤24.9 | 1.08 (1.04, 1.12)*** | 1.05 (1.02, 1.09)** | 1.05 (1.02, 1.09)** | 1.05 (1.01, 1.09)* |
| 24.9<BMI≤29.9 | 1.02 (0.98, 1.07) | 1.01 (0.96, 1.05) | 1.00 (0.96, 1.04) | 1.00 (0.96, 1.04) |
| BMI>29.9 | 1.02 (1.01, 1.03)** | 1.02 (1.00, 1.03)* | 1.02 (1.00, 1.03)* | 1.02 (1.00, 1.03)* |
Note: Model 1: no covariates were adjusted. Model 2: age, race/ethnicity and education level were adjusted; Model 3 age, race/ethnicity, education level and BMI were adjusted; Model 4: covariates listed in Table 1 were adjusted. In the subgroup analysis stratified by BMI, the models were not adjusted for BMI.
*P < 0.05
**P < 0.01
***P < 0.001