Table 1 General characteristics and incidence of congenital malformations between women with and without folic acid supplementation
From: Initiation and duration of folic acid supplementation in preventing congenital malformations
General characteristics and congenital malformations | Folic acid supplementation | |||
|---|---|---|---|---|
Yes (N = 15,848) | No (N = 887) | Total (N = 16,735) | P value | |
Region | Â | Â | Â | 0.32 |
 East | 7900 (49.8) | 442 (49.8) | 8345 |  |
 West | 4084 (25.8) | 210 (23.7) | 4301 |  |
 North | 2974 (18.8) | 176 (19.8) | 3150 |  |
 Central | 890 (5.6) | 59 (6.7) | 949 |  |
Han ethnicity | 15,119 (95.4) | 845 (95.3) | 15,964 (95.4) | 0.67 |
Education level (years) |  |  |  |  < 0.001 |
  < 9 | 1426 (9.0) | 137 (15.4) | 1563 (9.3) |  |
 10–12 | 2157 (13.6) | 157 (17.7) | 2314 (13.8) |  |
 13–15 | 4044 (25.5) | 241 (27.2) | 4285 (25.6) |  |
  ≥ 16 | 8221 (51.9) | 352 (39.7) | 8573 (51.2) |  |
Family income (RMB Yuan per person per month)a | Â | Â | Â | 0.043 |
  < 3000 | 537 (3.4) | 35 (3.9) | 572 (3.4) |  |
 3000–5000 | 4936 (31.1) | 308 (34.7) | 5244 (31.3) |  |
 5001–8000 | 5149 (32.5) | 284 (32.0) | 5433 (32.5) |  |
  > 8000 | 4770 (30.1) | 230 (25.9) | 5000 (29.9) |  |
History of adverse pregnant outcomesb | 2884 (18.2) | 129 (14.5) | 3013 (18.0) | 0.006 |
Early-pregnant conditionsc | 6169 (38.9) | 308 (34.7) | 6477 (38.7) | 0.012 |
Natural conception | 14,649 (92.4) | 862 (97.2) | 15,511 (92.7) |  < 0.001 |
Periconceptional medicine exposure | 4221 (26.6) | 194 (21.9) | 4415 (26.4) | 0.002 |
Nulliparous women | 10,812 (68.2) | 441 (49.7) | 11,253 (67.2) |  < 0.001 |
Maternal age (years) | Â | Â | Â | 0.001 |
  < 25 | 1527 (9.6) | 109 (12.3) | 1636 (9.8) |  |
 25–34 | 12,679 (80.0) | 663 (74.7) | 13,342 (79.7) |  |
  ≥ 35 | 1642 (10.4) | 115 (13.0) | 1757 (10.5) |  |
Congenital malformations | ||||
 Total, no. (%) | 252 (1.6) | 21 (2.4) | 273 (1.6) | 0.075 |
 Heart defects, no. (per 1000 infants) | 60 (3.8) | 7 (7.9) | 67 (4.0) | 0.089 |
 Neural tube defects, no. (per 10,000 infants) | 11 (6.9) | 1 (11.3) | 12 (7.2) | 0.47 |