Table 1. Parental Characteristics by Maternal Use of Supplements From 4 Weeks Before to 8 Weeks After Conceptiona.
| Characteristics | No. (%) | ||||
|---|---|---|---|---|---|
| Total (N = 38954) | No Supplements (n = 9460) | Other Supplements, No Folic Acid (n = 2586) | Folic Acid Only (n = 7354) | Folic Acid Plus Other Supplements (n = 19554) | |
| Maternal education, y | |||||
| <12 | 6671 (17.1) | 2510 (26.5) | 546 (21.1) | 1194 (16.2) | 2421 (12.4) |
| 12 | 4656 (12.0) | 1484 (15.7) | 397 (15.4) | 883 (12.0) | 1892 (9.7) |
| 13-16 | 17 189 (44.1) | 3668 (38.8) | 1052 (40.7) | 3426 (46.6) | 9043 (46.2) |
| ≥17 | 9576 (24.6) | 1526 (16.1) | 526 (20.3) | 1688 (23.0) | 5836 (29.8) |
| Missing data | 862 (2.2) | 272 (2.9) | 65 (2.5) | 163 (2.2) | 362 (1.9) |
| Paternal education, y | |||||
| <12 | 12 845 (33.0) | 4001 (42.3) | 974 (37.7) | 2447 (33.3) | 5423 (33.0) |
| 12 | 3894 (10.0) | 1041 (11.0) | 267 (10.3) | 780 (10.3) | 1806 (10.0) |
| 13-16 | 10 879 (27.9) | 2226 (23.5) | 689 (26.6) | 2104 (26.6) | 5860 (27.9) |
| ≥17 | 8951 (23.0) | 1488 (15.7) | 486 (18.8) | 1612 (18.8) | 5365 (23.0) |
| Missing data | 2385 (6.1) | 704 (7.4) | 170 (6.6) | 411 (6.6) | 1100 (6.1) |
| Maternal age, y | |||||
| <25 | 3741 (9.6) | 1228 (13.0) | 290 (11.2) | 664 (9.0) | 1559 (8.0) |
| 25-29 | 13 140 (33.7) | 3087 (32.6) | 759 (29.4) | 2622 (35.7) | 6672 (34.1) |
| 30-34 | 15 423 (39.6) | 3459 (36.6) | 990 (38.3) | 2963 (40.3) | 8011 (41.0) |
| ≥35 | 6650 (17.1) | 1686 (17.8) | 547 (21.2) | 1105 (15.0) | 3312 (16.9) |
| Paternal age, y | |||||
| <25 | 1537 (3.9) | 541 (5.7) | 128 (4.9) | 271 (3.7) | 597 (3.1) |
| 25-29 | 8774 (22.5) | 2096 (22.2) | 526 (20.3) | 1681 (22.9) | 4471 (22.9) |
| 30-34 | 15 632 (40.1) | 3570 (37.7) | 950 (36.7) | 3037 (41.3) | 8075 (41.3) |
| 35-39 | 9122 (23.4) | 2220 (23.5) | 653 (25.3) | 1672 (22.7) | 4577 (23.4) |
| ≥40 | 3809 (9.8) | 1014 (10.7) | 325 (12.6) | 684 (9.3) | 1786 (9.1) |
| Missing data | 80 (0.2) | 19 (0.2) | 4 (0.2) | 9 (0.1) | 48 (0.2) |
| Planned pregnancy | |||||
| No | 6674 (17.1) | 2131 (22.5) | 590 (22.8) | 987 (13.4) | 2966 (15.2) |
| Yes | 31 852 (81.8) | 7204 (76.2) | 1957 (75.7) | 6288 (85.5) | 16 403 (83.9) |
| Missing data | 428 (1.1) | 125 (1.3) | 39 (1.5) | 79 (1.1) | 185 (0.9) |
| Maternal smokingb | |||||
| No | 35 840 (92.0) | 8193 (86.6) | 2323 (89.8) | 6858 (93.3) | 18 466 (94.4) |
| Yes | 2840 (7.3) | 1163 (12.3) | 237 (9.2) | 454 (6.2) | 986 (5.0) |
| Missing data | 274 (0.7) | 104 (1.1) | 26 (1.0) | 42 (0.6) | 102 (0.5) |
| Maternal alcohol intakec | |||||
| No | 30 664 (78.7) | 7206 (76.2) | 1920 (74.2) | 5857 (79.6) | 15 681 (80.2) |
| Yes | 4812 (12.4) | 1296 (13.7) | 405 (15.7) | 827 (11.2) | 2284 (11.7) |
| Missing data | 3478 (8.9) | 958 (10.1) | 261 (10.1) | 670 (9.1) | 1589 (8.1) |
| Maternal BMI | |||||
| <25 | 26 211 (67.3) | 5908 (62.5) | 1776 (68.7) | 4789 (65.1) | 13 738 (70.3) |
| 25-29 | 8354 (21.4) | 2205 (23.3) | 546 (21.1) | 1701 (23.1) | 3902 (20.0) |
| 30-34 | 2549 (6.5) | 781 (8.3) | 146 (5.6) | 505 (6.9) | 1117 (5.7) |
| ≥35 | 905 (2.3) | 270 (2.9) | 58 (2.2) | 178 (2.4) | 399 (2.0) |
| Missing data | 935 (2.4) | 296 (3.1) | 60 (2.3) | 181 (2.5) | 398 (2.0) |
| Parityd | |||||
| 0 | 18 575 (47.7) | 3889 (41.1) | 1142 (44.2) | 3314 (45.1) | 10 230 (52.3) |
| 1 | 13 674 (35.1) | 3349 (35.4) | 848 (32.8) | 2848 (38.7) | 6629 (33.9) |
| ≥2 | 6705 (17.2) | 2222 (23.5) | 596 (23.0) | 1192 (16.2) | 2695 (13.8) |
| Maternal height, m | |||||
| <1.65 | 9910 (25.4) | 2619 (27.7) | 660 (25.5) | 1870 (25.4) | 4761 (24.3) |
| 1.65-1.68 | 10 008 (25.7) | 2377 (25.1) | 678 (26.2) | 1903 (25.9) | 5050 (25.8) |
| 1.69-1.72 | 9518 (24.4) | 2227 (23.5) | 614 (23.7) | 1799 (24.5) | 4878 (24.9) |
| >1.72 | 9115 (23.4) | 2115 (22.4) | 609 (23.5) | 1697 (23.1) | 4694 (24.0) |
| Missing data | 403 (1.0) | 122 (1.3) | 25 (1.0) | 85 (1.2) | 171 (0.9) |
| Marital statuse | |||||
| Married or living with partner | 36 214 (93.0) | 8584 (90.7) | 2349 (90.8) | 6882 (93.6) | 18 399 (94.1) |
| Single | 1150 (3.0) | 401 (4.2) | 101 (3.9) | 168 (2.3) | 480 (2.5) |
| Other | 675 (1.7) | 189 (2.0) | 48 (1.9) | 124 (1.7) | 314 (1.6) |
| Missing data | 915 (2.3) | 286 (3.0) | 88 (3.4) | 180 (2.4) | 361 (1.8) |
| Infant nutrition at 6 mo | |||||
| Breast milk | 22 588 (58.0) | 5129 (54.2) | 1523 (58.9) | 4249 (57.8) | 11 687 (59.8) |
| Infant formula | 4844 (12.4) | 1518 (16.0) | 315 (12.2) | 904 (12.3) | 2107 (10.8) |
| Breast milk and infant formula | 7693 (19.7) | 1785 (18.9) | 480 (18.6) | 1461 (19.9) | 3967 (20.3) |
| Missing data | 3829 (9.8) | 1028 (10.9) | 268 (10.4) | 740 (10.1) | 1793 (9.2) |
Abbreviation: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared)
a
P< .001 for all variables, 2-sided χ2 test of independence.
b
Maternal smoking, daily or sometimes, in this pregnancy.
c
Use of 1 or more alcoholic units per week in the first trimester. One unit equals 1.5 cL of pure alcohol
d
Parity including abortion after week 22.
e
Marital status from age 3 years questionnaire