Table II.
Associations with Time to Pregnancy in a Multivariable Modela
| Variable | Fecundability odds ratio | 95% CI | Score test P-value (two-sided) |
|---|---|---|---|
| Age (per year) | 0.96 | 0.92, 1.00 | 0.04 |
| Unprotected intercourse during the ovulatory window (times per window) | 1.36 | 1.25, 1.48 | < 0.0001 |
| Trying to get pregnant | 0.002 | ||
| No | Ref | ||
| Yes | 1.80 | 1.23, 2.60 | |
| Body mass index (kg/m2) | 0.02 | ||
| <18.5 | 0.69 | 0.27, 1.75 | |
| 18.5–<25 | Ref | ||
| 25–<30 | 0.83 | 0.54, 1.30 | |
| 30+ | 0.40 | 0.21, 0.73 | |
| Average caffeine intake | 0.83 | ||
| <150 mg/day | Ref | ||
| 150–300 mg/day | 1.02 | 0.67, 1.56 | |
| 300+ mg/day | 0.89 | 0.58, 1.38 | |
| Average alcohol intake | 0.05 | ||
| None | Ref | ||
| <1 drink/day | 0.70 | 0.47, 1.04 | |
| ≥1 drink/day | 0.50 | 0.28, 0.89 | |
| Smoking | 0.80 | ||
| None | Ref | ||
| <10 cigarettes/day | 1.04 | 0.65, 1.67 | |
| ≥10 cigarettes/day | 1.19 | 0.71, 2.00 |
a
All variables listed are in the model simultaneously.