Table 2.
Maternal Characteristics by Maternal Use of Supplements From 4 Weeks Before to 8 Weeks After Conception Among 102 985 Births Without Chromosomal Aberrations in MoBa, Norway, 1999–2009
| Characteristics | TotalN=102 985 (100%) | No Supplementsn=25 229 (24.5%) | Other Supplements No Folic Acidn=6431 (6.24%) | Folic Acid Onlyn=19 555 (19.0%) | Folic Acid Plus Other Supplementsn=51 770 (50.3%) | P Value, No Folic Acid vs Folic Acid usea |
|---|---|---|---|---|---|---|
| Year of birthb | ||||||
| 1999 | 46 (0.04) | 30 (65.2) | 4 (8.7) | 6 (13.0) | 6 (13.0) | <0.0001 |
| 2000 | 2010 (2.0) | 1047 (52.1) | 223 (11.1) | 316 (15.7) | 424 (21.1) | |
| 2001 | 3931 (3.8) | 1890 (48.8) | 443 (11.3) | 609 (15.5) | 989 (25.2) | |
| 2002 | 8293 (8.1) | 3960 (47.8) | 846 (10.2) | 1321 (15.9) | 2166 (26.1) | |
| 2003 | 12 142 (11.8) | 4615 (38.0) | 1133 (9.3) | 2208 (18.2) | 4186 (34.5) | |
| 2004 | 13 073 (12.7) | 3282 (25.1) | 845 (6.5) | 2541 (19.4) | 6405 (49.0) | |
| 2005 | 15 117 (14.7) | 3181 (21.0) | 785 (5.2) | 3094 (20.5) | 8057 (53.3) | |
| 2006 | 16 775 (16.3) | 2872 (17.1) | 867 (5.2) | 3177 (18.9) | 9859 (58.8) | |
| 2007 | 15 474 (15.0) | 2265 (14.6) | 661 (4.3) | 3028 (19.6) | 9520 (61.5) | |
| 2008 | 12 904 (12.5) | 1695 (13.1) | 514 (4.0) | 2620 (20.3) | 8075 (62.6) | |
| 2009 | 3220 (3.1) | 392 (12.2) | 110 (3.4) | 635 (19.7) | 2083 (64.7) | |
| Maternal age, yb | ||||||
| ≤24 | 11 301 (11.0) | 3999 (35.4) | 883 (7.8) | 2011 (17.8) | 4408 (39.0) | <0.0001 |
| 25–29 | 33 730 (32.8) | 7920 (23.5) | 1846 (5.5) | 6739 (20.0) | 17 225 (51.1) | |
| 30–34 | 39 916 (38.8) | 8881 (22.3) | 2378 (6.0) | 7772 (19.5) | 20 885 (52.3) | |
| ≥35 | 18 038 (17.5) | 4429 (24.6) | 1324 (7.3) | 3033 (16.8) | 9252 (51.3) | |
| Birth orderb | ||||||
| First | 46 367 (45.0) | 9566 (20.6) | 2723 (5.9) | 8282 (17.9) | 25 796 (55.6) | <0.0001 |
| Second | 36 576 (35.5) | 8936 (24.4) | 2105 (5.8) | 7616 (20.8) | 17 919 (49.0) | |
| Third or higher | 20 042 (19.5) | 6727 (33.6) | 1603 (8.0) | 3657 (18.3) | 8055 (40.2) | |
| Maternal body mass index before pregnancy (kg/m2)b | ||||||
| <20 | 12 700 (12.3) | 2953 (23.3) | 875 (6.9) | 2104 (16.6) | 6768 (53.3) | <0.0001 |
| 20–24 | 56 079 (54.5) | 12 656 (22.6) | 3592 (6.4) | 10 450 (18.6) | 29 381 (52.4) | |
| 25–29 | 21 735 (21.1) | 5671 (26.1) | 1273 (5.9) | 4505 (20.7) | 10 286 (47.3) | |
| 30–24 | 7067 (6.9) | 2154 (30.5) | 366 (5.2) | 1442 (20.4) | 3105 (43.9) | |
| ≥35 | 2608 (2.5) | 784 (30.1) | 132 (5.1) | 553 (21.2) | 1139 (43.7) | |
| Missing data | 2796 (2.7) | 1011 (36.2) | 193 (6.9) | 501 (17.9) | 1091 (39.0) | |
| Maternal heart defect | ||||||
| Yes | 640 (0.62) | 160 (25.0) | 48 (7.5) | 103 (16.1) | 329 (51.4) | 0.20 |
| No | 102 345 (99.4) | 25 069 (24.5) | 6383 (6.2) | 19 452 (19.0) | 51 441 (50.3) | |
| Epilepsy before pregnancy | ||||||
| Yes | 687 (0.67) | 160 (23.3) | 28 (4.1) | 140 (20.4) | 359 (52.3) | 0.08 |
| No | 102 298 (99.3) | 25 069 (24.5) | 6403 (6.3) | 19 415 (19.0) | 51 411 (50.3) | |
| Prepregnancy diabetes mellitusc | ||||||
| Yes | 698 (0.68) | 172 (24.6) | 40 (5.7) | 123 (17.6) | 363 (52.0) | 0.70 |
| No | 102 287 (99.3) | 25 057 (24.5) | 6391 (6.25) | 19 432 (19.0) | 51 407 (50.2) | |
| Smoking before pregnancy | ||||||
| Daily | 18 598 (18.1) | 6574 (35.4) | 1318 (7.1) | 3438 (18.5) | 7268 (39.1) | <0.0001 |
| Sometimes | 10 309 (10.0) | 2388 (23.2) | 628 (6.1) | 1917 (18.6) | 5376 (52.2) | |
| No | 61 352 (59.6) | 11 346 (18.5) | 3315 (5.4) | 11 929 (19.4) | 34 762 (56.7) | |
| Missing | 12 726 (12.4) | 4921 (38.7) | 1170 (9.2) | 2271 (17.9) | 4364 (34.3) | |
| Prepregnancy alcohol intaked | ||||||
| Yes | 88 509 (85.9) | 16 824 (20.4) | 4635 (5.61) | 16 027 (19.4) | 45 149 (54.6) | <0.0001 |
| No | 7167 (6.96) | 1459 (34.0) | 363 (8.46) | 785 (18.3) | 1686 (39.3) | |
| Missing | 7309 (7.10) | 1878 (44.7) | 419 (9.97) | 702 (16.7) | 1205 (28.7) | |
| Maternal education, y | ||||||
| <12 | 20 535 (19.9) | 7987 (38.9) | 1648 (8.03) | 3661 (17.8) | 7239 (35.3) | <0.0001 |
| 12 | 14 458 (14.0) | 4393 (30.4) | 1081 (7.48) | 2717 (18.8) | 6267 (43.4) | |
| 13–16 | 39 916 (38.8) | 8021 (20.1) | 2229 (5.58) | 8071 (20.2) | 21 595 (54.1) | |
| ≥17 | 22 816 (22.2) | 3337 (14.6) | 1116 (4.89) | 4166 (18.3) | 14 197 (62.2) | |
| Missing data | 5260 (5.11) | 1491 (28.4) | 357 (6.79) | 940 (17.9) | 2472 (47.0) | |
| Planned pregnancy | ||||||
| Yes | 82 078 (79.7) | 18 144 (22.1) | 4664 (5.68) | 16 377 (20.0) | 42 893 (52.3) | <0.0001 |
| No | 19 673 (19.1) | 6658 (33.8) | 1672 (8.50) | 2997 (15.2) | 8346 (42.4) | |
| Missing data | 1234 (1.20) | 427 (34.6) | 95 (7.70) | 181 (14.7) | 531 (43.0) | |
| Pluralityb | ||||||
| Single | 99 320 (96.4) | 24 450 (24.6) | 6226 (6.3) | 18 800 (18.9) | 49 844 (50.2) | <0.0001 |
| Twins/triplets | 3665 (3.6) | 779 (21.3) | 205 (5.6) | 755 (20.6) | 1926 (52.6) | |
Data are shown as n (%). MBRN indicates Medical Birth Registry of Norway; MoBa, Norwegian Mother and Child Cohort Study.
a
No folic acid use (no/other supplements, no folic acid) vs folic acid use (folic acid only/folic acid plus other supplements) 4 weeks before to 8 weeks after gestation (combining −4 to 0, 0–4, and 5–8 weeks).
b
Numbers from MBRN.
c
Diabetes mellitus type 1 or type 2 before pregnancy, registered in MoBa and/or MBRN.
d
Alcohol intake 3 months before pregnancy.