Table 1:
Maternal characteristics of the study sample (n= 348,250)* of live singleton births in the state of Missouri during 2004-2008, shown in n(%).
| Normal Births (n= 344,566) |
Neural Tube (n= 196) |
Congenital Heart (n= 442) |
Oral Cleft (n= 643) |
Limb Deficiencies (n= 142) |
Gastroschisis (n= 273) |
Hypospadias (n= 1,609) |
Down Syndrome (n= 500) |
|
|---|---|---|---|---|---|---|---|---|
| Race | ||||||||
| White | 288,158 (83.6) | 179 (91.3) | 383 (86.7) | 572 (89.0) | 127 (89.4) | 219 (80.3) | 1,344 (83.5) | 429 (85.8) |
| Black | 43,207 (12.5) | 14 (7.1) | 47 (10.6) | 47 (7.3) | 14 (9.9) | 46 (16.8) | 224 (13.9) | 49 (9.8) |
| Other | 11,920 (3.4) | - | 10 (2.3) | 20 (3.1) | - | 7 (2.6) | 35 (2.2) | 19 (3.8) |
| Missing | 1,281 (0.4) | - | - | - | - | - | 6 (0.4) | - |
| Ethnicity | ||||||||
| Hispanic | 19,449 (5.6) | 15 (7.6) | 11 (2.5) | 41 (6.4) | 5(3.5) | 11 (4.0) | 50 (3.1) | 40 (8.0) |
| Non-Hispanic | 324,745 (94.2) | 181 (92.4) | 430 (97.3) | 601 (93.5) | 137 (96.5) | 262 (96.0) | 1,558 (96.8) | 460 (92.0) |
| Missing | 372 (0.1) | 0 (0.0) | - | - | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Age Group (years) | ||||||||
| <18 | 11,876 (3.4) | - | 9 (2.0) | 19 (3.0) | 6 (4.2) | 22 (8.1) | 58 (3.6) | 6 (1.2) |
| 18–34 | 297,112 (86.2) | 168 (85.7) | 376 (85.1) | 546 (84.9) | 125 (88.0) | 233 (85.3) | 1,388 (86.3) | 300 (60.0) |
| >34 | 35,565 (9.7) | 24 (12.2) | 57 (12.9) | 78 (12.1) | 11 (7.7) | 18 (6.6) | 163 (10.1) | 194 (38.8) |
| Missing | 13 (<0.1) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| BMI Pre-pregnancy | ||||||||
| < 18.5 | 16,287 (4.7) | 8 (4.1) | 21 (4.8) | 40 (6.2) | 6 (4.2) | 10 (3.7) | 68 (4.2) | 19 (3.8) |
| 18.5–24.9 | 160,560 (46.6) | 73 (37.2) | 189 (42.8) | 279 (43.4) | 68 (47.9) | 150 (55.0) | 702 (43.6) | 229 (45.8) |
| 25–29.9 | 76,963 (22.3) | 47 (24.0) | 86 (19.5) | 138 (21.5) | 30 (21.1) | 52 (19.1) | 381 (23.7) | 112 (22.4) |
| >30.0 | 90,756 (26.3) | 68 (34.7) | 146 (33.0) | 186 (28.9) | 38 (26.8) | 61 (22.3) | 458 (28.5) | 140 (28.0) |
| Missing | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Education (years) | ||||||||
| <12 | 63,773 (18.5) | 33 (16.8) | 77 (17.4) | 142 (22.1) | 28 (19.7) | 90 (33.0) | 238 (14.8) | 74 (14.8) |
| 12 | 106,171 (30.8) | 78 (39.8) | 146 (33.0) | 209 (32.5) | 40 (28.2) | 93 (34.1) | 506 (31.5) | 144 (28.8) |
| 13–15 | 79,061 (23.0) | 42 (21.4) | 100 (22.6) | 146 (22.7) | 38 (26.8) | 58 (21.3) | 380 (23.6) | 111 (22.2) |
| >15 | 92,003 (26.7) | 39 (19.9) | 111 (25.1) | 140 (21.8) | 35 (24.6) | 29 (10.6) | 469 (29.2) | 165 (33.0) |
| Missing | 3,558 (1.0) | - | 8(1.8) | 6 (0.9) | - | - | 16 (1.0) | 6 (1.2) |
| Smoker | ||||||||
| No | 279,512 (81.1) | 166 (84.7) | 352 (79.6) | 501 (77.9) | 107 (75.3) | 189 (69.2) | 1,344 (83.5) | 417 (83.4) |
| Yes | 63,878 (18.5) | 28 (14.3) | 88 (19.9) | 137 (21.3) | 34 (23.9) | 82 (30.0) | 255 (15.8) | 81 (16.2) |
| Missing | 1,176 (0.3) | - | - | 5 (0.7) | - | - | 10 (0.6) | - |
| Alcohol during Pregnancy | ||||||||
| No | 339,447 (98.5) | 185 4.3) | 431 (7.5) | 636 (98.9) | 139 (97.9) | 269 (98.5) | 1,584 (98.4) | 488 (97.6) |
| Yes | 2,021 (0.6) | 5 (2.6) | 5 (1.1) | - | - | - | 12 (0.7) | 7 (1.4) |
| Missing | 3,098 (0.9) | 6 (3.0) | 6 (1.3) | 5 (0.8) | - | - | 13 (0.8) | 5 (1.0) |
| Low SES a | ||||||||
| No | 155,885 (45.2) | 95 (48.4) | 195 (44.1) | 278 (43.2) | 65 (45.8) | 56 (20.5) | 779 (48.4) | 277 (55.4) |
| Yes | 184,470 (53.5) | 96 (49.0) | 240 (54.3) | 362 (56.2) | 76 (53.5) | 213 (78.0) | 816 (50.7) | 217 (43.4) |
| Missing | 4,211 (1.2) | 5 (2.6) | 7 (1.6) | - | - | - | 14 (0.9) | 6 (1.2) |
| Adequate Prenatal Care b | ||||||||
| No | 35,249 (10.2) | 30 (15.3) | 39 (8.8) | 63 (9.8) | 19 (13.4) | 33 (12.1) | 133 (8.3) | 59 (11.8) |
| Yes | 293,952 (85.3) | 151 (77.0) | 385 (87.1) | 551 (85.7) | 114(80.2) | 213 (78.0) | 1,409 (87.6) | 422 (84.4) |
| Missing | 15,365 (4.4) | 15 (7.7) | 18 (4.1) | 29 (4.5) | 9 (6.3) | 27 (9.9) | 67 (4.2) | 19 (3.8) |
| Child Sex | ||||||||
| Male | 175,548 (50.9) | 102 (52.0) | 263 (59.5) | 354 (55.0) | 76 (53.5) | 152 (55.7) | 1,609 (100) | 269 (53.8) |
| Female | 169,013 (49.1) | 93 (47.4) | 179 (40.5) | 289 (45.0) | 66 (46.4) | 121 (44.3) | 0 (0.0) | 231 (46.2) |
| Missing | 5 (≥ .1) | - | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Child Birth Year | ||||||||
| 2004 | 68,973 (20.0) | 37 (18.9) | 93 (21.04) | 115 (17.9) | 23 (16.2) | 49 (17.9) | 289 (18.0) | 94 (18.8) |
| 2005 | 69,596 (20.2) | 48 (24.5) | 95 (21.5) | 144 (22.4) | 37 (26.1) | 51 (18.7) | 346 (21.5) | 108 (21.6) |
| 2006 | 69,750 (20.2) | 27 (13.8) | 81 (18.3) | 117 (18.2) | 31 (21.8) | 46 (16.8) | 323 (20.1) | 102 (20.4) |
| 2007 | 70,235 (20.4) | 39 (19.9) | 96 (21.7) | 158 (24.6) | 16 (11.3) | 69 (25.3) | 327 (20.3) | 112 (22.4) |
| 2008 | 66,012 (19.2) | 45 (23.0) | 77 (17.4) | 109 (17.0) | 35 (24.7) | 58 (21.3) | 324 (20.1) | 84 (16.8) |
| Nitrate Exposure (quartiles)c | ||||||||
| Ql | 88,194 (25.6) | 47 (24.0) | 117 (26.5) | 167 (26.0) | 38 (26.8) | 69 (25.3) | 431 (26.7) | 137 (27.4) |
| Q2 | 84,138 (24.4) | 52 (26.5) | 102 (23.1) | 151 (23.5) | 20 (14.1) | 61 (22.3) | 390 (24.2) | 137 (27.4) |
| Q3 | 92,405 (26.8) | 52 (26.5) | 117 (26.5) | 182 (28.3) | 35 (24.6) | 82 (30.0) | 414 (25.7) | 121 (24.2) |
| Q4 | 79,829 (23.2) | 45 (23.0) | 106 (24.0) | 143 (22.2) | 49 (34.5) | 61 (22.3) | 378 (23.4) | 105 (21.0) |
a
Low socioeconomic status is defined as participation in one or more of the following public assistance programs: WIC, Medicaid, or federal food stamp programs.
b
Adequate prenatal care is defined as live births with five or more prenatal care visits for pregnancies lasting less than 37 weeks of gestation, eight or more visits for pregnancies lasting 37 or more weeks, or prenatal care that began during the first four months of pregnancy.
c
Q1 = 0.025 - < .082 mg/L, Q2 = .082 - < 0.18 mg/L, Q3 = 0.18 – < 0.34 mg/L, Q4 = 0.34 – 6.36 mg/L
*
Total of summarized births is greater than 348,250 as 121 births had more than one recorded birth defect.
Dashes indicate censoring due to low cell count in order to protect subject privacy.
Bold indicates a statistically significant (i.e. p<0.05) difference in proportions in comparison to non-cases.