Table 1 Characteristics of study participants
Characteristic | Case (148a) n (%)b | Control (299a) n (%)b | p c |
|---|---|---|---|
Age (year) | 144 | 298 | 0.096 |
<20 | 9 (6.25) | 22 (7.38) | |
20–29 | 112 (77.78) | 203 (68.12) | |
>29 | 23 (15.97) | 73 (24.50) | |
Educational level | 138 | 269 | |
<Middle school graduation | 14 (10.14) | 25 (9.29) | 0.157 |
Middle school graduation | 106 (76.81) | 188 (69.89) | |
>Middle school graduation | 18 (13.04) | 56 (20.81) | |
Gravidity (n) | 137 | 269 | |
1 | 9 (6.57) | 27 (10.04) | 0.507 |
2 | 15 (10.95) | 29 (10.78) | |
≥3 | 113 (82.48) | 213 (79.18) | |
Parity (n) | 137 | 269 | |
0 | 14 (10.22) | 27 (10.04) | 0.530 |
1 | 10 (7.30) | 29 (10.78) | |
≥2 | 113 (82.48) | 213 (79.18) | |
Periconceptional folic acid used | 123 | 254 | |
No | 116 (94.31) | 246 (96.85) | 0.265 |
Yes | 7 (5.69) | 8 (3.15) | |
Gestational week | 145 | 291 | |
<21 | 82 (56.55) | 203 (69.76) | 0.016 |
21–29 | 41 (28.28) | 63 (21.65) | |
≥30 | 22 (15.17) | 25 (8.59) |