Table 1.
General participant characteristics.
| Nonuser | User | |||||||
|---|---|---|---|---|---|---|---|---|
| Non-FA (n = 1028) | Total (n = 9634) | Early pregnancy | Whole pregnancy | |||||
| 0.4 FA (n = 4321) | MV + 0.4 FA (n = 831) | MV + 0.8 FA (n = 2309) | 0.4 FA (n = 838) | MV + 0.4 FA (n = 418) | MV + 0.8 FA (n = 917) | |||
| Age at pregnancy, yrs (mean ± SD) | 30.63 ± 4.97 | 30.08 ± 3.98 | 30.10 ± 4.05 | 29.89 ± 3.83 | 29.56 ± 3.88 | 30.41 ± 3.99 | 30.27 ± 3.81 | 31.09 ± 3.86 |
| Body mass index, kg/m2 (mean ± SD) | 21.88 ± 3.23 | 21.44 ± 3.01 | 21.51 ± 3.04 | 21.34 ± 2.99 | 21.40 ± 3.04 | 21.42 ± 2.93 | 21.49 ± 3.08 | 21.32 ± 2.88 |
| Han ethnicity N (%) | 1014 (98.64) | 9525 (98.87) | 4264 (98.68) | 819 (98.56) | 2284 (98.92) | 832 (99.28) | 414 (99.04) | 912 (99.45) |
| Education level ≥12 yrs N (%) | 587 (57.10) | 7326 (76.04) | 3139 (72.65) | 682 (82.07) | 1708 (73.97) | 658 (78.52) | 358 (85.65) | 781 (85.17) |
| Primiparous N (%) | 522 (50.78) | 6592 (68.42) | 2817 (65.19) | 606 (72.92) | 1644 (71.20) | 539 (64.32) | 320 (76.56) | 666 (72.63) |
| Infant gender (male/female) N (%) | 532 (51.75) | 5016 (52.07) | 2254 (52.16) | 432 (51.99) | 1130 (48.94) | 419 (50.00) | 237 (56.70) | 544 (59.32) |
| Pregnancy complications N (%) | 201 (19.55) | 1612 (16.73) | 778 (18.01) | 124 (14.92) | 281 (12.17) | 187 (22.32) | 65 (15.55) | 177 (19.30) |
| HDCP N (%) | 36 (3.50) | 211 (2.19) | 109 (2.52) | 22 (2.65) | 35 (1.52) | 19 (2.27) | 10 (2.39) | 16 (1.74) |
| Preeclampsia N (%) | 14 (1.36) | 56 (0.58) | 31 (0.72) | 8 (0.96) | 3 (0.13) | 5 (0.60) | 4 (0.96) | 5 (0.55) |
| GDM N (%) | 100 (9.73) | 1014 (10.53) | 457 (10.58) | 72 (8.66) | 205 (8.88) | 120 (14.32) | 43 (10.29) | 117 (12.76) |
| Cigarette smoking N (%) | 147 (14.30) | 1453 (15.08) | 665 (15.39) | 121 (14.56) | 286 (12.39) | 165 (19.67) | 61 (14.59) | 155 (16.90) |
| Alcohol drinking N (%) | 29 (2.82) | 352 (3.65) | 147 (3.40) | 43 (5.17) | 78 (3.38) | 30 (3.58) | 27 (6.46) | 27 (2.94) |
FA: folic acid, 0.4 FA: 0.4 mg folic acid, MV + 0.4 FA: multivitamins with 0.4 mg folic acid, MV + 0.8 FA: multivitamins with 0.8 mg folic acid. HDCP: hypertensive disorder complicating pregnancy, GDM: gestational diabetes mellitus.