Table 2.
Characteristics of Controls and Cases of LD Case Groups, the NBDPS 1997 to 2007
| Controls | All limb deficiencies |
Longitudinal | Longitudinal preaxial |
Transverse | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Maternal and pregnancy characteristics | No. | % | No. | % | No. | % | No. | % | No. | % |
| Sex | ||||||||||
| Male | 4104 | (50.9) | 477 | (56.5) | 185 | (57.1) | 108 | (55.7) | 275 | (56.4) |
| Female | 3957 | (49.0) | 360 | (42.7) | 134 | (41.4) | 82 | (42.3) | 211 | (43.2) |
| Maternal age at conception | ||||||||||
| 12–19 | 1066 | (13.2) | 128 | (15.2) | 52 | (16.0) | 34 | (17.5) | 69 | (14.1) |
| 20–34 | 6106 | (75.7) | 638 | (75.6) | 244 | (75.3) | 142 | (73.2) | 372 | (76.2) |
| 35+ | 897 | (11.1) | 78 | (9.2) | 28 | (8.6) | 18 | (9.3) | 47 | (9.6) |
| Maternal race/ethnicity | ||||||||||
| Non-Hispanic White | 4852 | (60.1) | 478 | (56.6) | 181 | (55.9) | 102 | (52.6) | 278 | (57.0) |
| Non-Hispanic Black | 898 | (11.1) | 82 | (9.7) | 43 | (13.3) | 31 | (16.0) | 36 | (7.4) |
| Hispanic | 1803 | (22.3) | 237 | (28.1) | 82 | (25.3) | 49 | (25.3) | 148 | (30.3) |
| Other | 513 | (6.4) | 47 | (5.6) | 18 | (5.6) | 12 | (6.2) | 26 | (5.3) |
| Maternal education | ||||||||||
| 0–12 years | 3283 | (40.7) | 374 | (44.3) | 144 | (44.4) | 99 | (51.0) | 214 | (43.9) |
| >12 years | 4755 | (58.9) | 465 | (55.1) | 179 | (55.2) | 95 | (49.0) | 271 | (55.5) |
| Parity | ||||||||||
| 0 | 3230 | (40.0) | 391 | (46.3) | 163 | (50.3) | 106 | (54.6) | 217 | (44.5) |
| ≥1 | 4838 | (60.0) | 453 | (53.7) | 161 | (49.7) | 88 | (45.4) | 271 | (55.5) |
| BMI | ||||||||||
| Underweight (BMI <18.5) | 420 | (5.2) | 49 | (5.8) | 20 | (6.2) | 12 | (6.2) | 26 | (5.3) |
| Normal weight (18.5 ≤ BMI <25) | 4279 | (53.0) | 421 | (49.9) | 159 | (49.1) | 98 | (50.5) | 242 | (49.6) |
| Overweight or obese (BMI ≥25) | 3047 | (37.8) | 329 | (39.0) | 130 | (40.1) | 77 | (39.7) | 193 | (39.5) |
| Fever during pregnancy | ||||||||||
| No | 7254 | (89.9) | 728 | (86.3) | 283 | (87.3) | 167 | (86.1) | 418 | (85.7) |
| Yes | 815 | (10.1) | 116 | (13.7) | 41 | (12.7) | 27 | (13.9) | 70 | (14.3) |
| Nausea or vomiting in the first month of pregnancy | ||||||||||
| No | 4588 | (56.9) | 522 | (61.8) | 208 | (64.2) | 124 | (63.9) | 289 | (59.2) |
| Yes | 3469 | (43.0) | 319 | (37.8) | 115 | (35.5) | 69 | (35.6) | 198 | (40.6) |
| Active and ETSa | ||||||||||
| No smoking or ETS | 5480 | (67.9) | 553 | (65.5) | 205 | (63.3) | 116 | (59.8) | 323 | (66.2) |
| ETS only | 1085 | (13.4) | 116 | (13.7) | 48 | (14.8) | 30 | (15.5) | 65 | (13.3) |
| Active smoking w/o ETS | 1486 | (18.4) | 172 | (20.4) | 70 | (21.6) | 47 | (24.2) | 98 | (20.1) |
| Alcohol drinkinga | ||||||||||
| No | 5038 | (62.4) | 565 | (66.9) | 221 | (68.2) | 138 | (71.1) | 319 | (65.4) |
| Yes | 2994 | (37.1) | 276 | (32.7) | 102 | (31.5) | 55 | (28.4) | 167 | (34.2) |
| Binge drinkinga | ||||||||||
| No drinking | 5038 | (62.4) | 565 | (66.9) | 221 | (68.2) | 138 | (71.1) | 319 | (65.4) |
| Drinking, not binge drinking | 1975 | (24.5) | 171 | (20.3) | 67 | (20.7) | 32 | (16.5) | 101 | (20.7) |
| Binge drinking (≥4 drinks/occasion) | 986 | (12.2) | 100 | (11.8) | 34 | (10.5) | 23 | (11.9) | 62 | (12.7) |
| Vasoconstrictive medicine usea | ||||||||||
| No | 7304 | (90.5) | 752 | (89.1) | 292 | (90.1) | 172 | (88.7) | 431 | (88.3) |
| Yes | 682 | (8.5) | 86 | (10.2) | 31 | (9.6) | 21 | (10.8) | 53 | (10.9) |
| Folic acid supplementb | ||||||||||
| No | 3917 | (48.5) | 401 | (47.5) | 142 | (43.8) | 89 | (45.9) | 244 | (50.0) |
| Yes | 4152 | (51.5) | 443 | (52.5) | 182 | (56.2) | 105 | (54.1) | 244 | (50.0) |
| Site | ||||||||||
| Arkansas | 1036 | (12.8) | 89 | (10.5) | 47 | (14.5) | 27 | (13.9) | 34 | (7.0) |
| California | 964 | (11.9) | 128 | (15.2) | 51 | (15.7) | 29 | (14.9) | 70 | (14.3) |
| Georgia (CDC) | 829 | (10.3) | 82 | (9.7) | 31 | (9.6) | 20 | (10.3) | 46 | (9.4) |
| Iowa | 910 | (11.3) | 86 | (10.2) | 30 | (9.3) | 20 | (10.3) | 55 | (11.3) |
| Massachusetts | 1018 | (12.6) | 104 | (12.3) | 41 | (12.7) | 20 | (10.3) | 63 | (12.9) |
| New Jersey | 561 | (7.0) | 76 | (9.0) | 23 | (7.1) | 14 | (7.2) | 51 | (10.5) |
| New York | 707 | (8.8) | 61 | (7.2) | 24 | (7.4) | 13 | (6.7) | 38 | (7.8) |
| North Carolina | 539 | (6.7) | 32 | (3.8) | 8 | (2.5) | 2 | (1.0) | 22 | (4.5) |
| Texas | 905 | (11.2) | 104 | (12.3) | 37 | (11.4) | 28 | (14.4) | 63 | (12.9) |
| Utah | 600 | (7.4) | 82 | (9.7) | 32 | (9.9) | 21 | (10.8) | 46 | (9.4) |
a
During 1 month before pregnancy through the first trimester.
b
During 1 month before pregnancy through the first month of gestation.
LD, limb deficiency; NBDPS, National Birth Defects Prevention Study; BMI, body mass index; ETS, environmental tobacco smoking; CDC, Centers for Disease Control.