Table 5.
Association between Maternal Caffeine Consumption and Spina Bifida Stratified by Maternal Cigarette Smoking, Alcohol Consumption, and Maternal Age at Conception for Index Pregnancy in the National Birth Defects Prevention Study, United States, 1997–2002
| Maternal caffeine (mg/day) | Spina bifida (N) | Controls (N) | ORb | (95% CI) | |
|---|---|---|---|---|---|
| Cigarette smokinga | |||||
| No | None (0–9) | 48 | 597 | 1.0 | |
| Any (≥10) | 315 | 2704 | 1.5 | (1.1, 2.0) | |
| Yes | None (0–9) | 6 | 38 | 1.0 | |
| Any (≥10) | 85 | 752 | 0.7 | (0.3, 1.7) | |
| Alcohol consumptiona | |||||
| No | None (0–9) | 36 | 471 | 1.0 | |
| Any (≥10) | 262 | 2020 | 1.7 | (1.2, 2.4) | |
| Yes | None (0–9) | 18 | 164 | 1.0 | |
| Any (≥10) | 139 | 1436 | 0.9 | (0.5, 1.5) | |
| Maternal age at conception | |||||
| <30 years | None (0–9) | 34 | 391 | 1.0 | |
| Any (≥10) | 282 | 2208 | 1.5 | (1.0, 2.2) | |
| ≥30 years | None (0–9) | 20 | 244 | 1.0 | |
| Any (≥10) | 119 | 1248 | 1.2 | (0.7, 1.9) | |
a
Any, one month before through the third month of pregnancy.
b
ORs stratified by cigarette smoking and age at conception adjusted for alcohol consumption. Additional adjustment for maternal pre-pregnancy obesity produced similar results.
CI, confidence interval; OR, odds ratio.