TABLE 4.
HRs for small-for-gestational-age (SGA) according to timing and intensity of periconceptional multivitamin use1
| SGA | Crude HR | Adjusted HR (95% CI)2 | |
| n (%) | — | ||
| Nonuser | 489 (4.2) | 1.00 | — |
| Multivitamin user (any) | 640 (2.9) | 0.76 | 0.83 (0.73, 0.95) |
| Preconception, postconception | |||
| −, − | 489 (4.3) | 1.00 | — |
| ++, ++ | 233 (2.7) | 0.73 | 0.89 (0.75, 1.05) |
| +, ++ | 63 (2.8) | 0.72 | 0.81 (0.62, 1.07) |
| −, ++ | 105 (2.4) | 0.67 | 0.68 (0.54, 0.85) |
| − or +, − or + | 239 (3.6) | 0.86 | 0.87 (0.74, 1.03) |
1
−, no use; +, 1–3 wk during the 6-wk interval; ++, 4–6 wk during the 6-wk interval.
2
Cox regression models were adjusted for age, parity, BMI, sociooccupational status, and smoking.