Table 1.
Maternal and offspring characteristics of study participants, Slone Birth Defects Study (1997–2009) and National Birth Defects Prevention Study (1997–2007).
| Slone Birth Defects Study | National Birth Defects Prevention Study |
|||
|---|---|---|---|---|
| Characteristics | Infants without malformations N = 6,983 |
Infants with CL/P N = 785 |
Infants without malformations N = 8,494 |
Infants with CL/P N = 2,283 |
| Maternal age in years, mean (SD) | 29.3 (5.9) | 28.5 (6.1) | 27.3 (6.1) | 27.0 (6.1) |
| Prepregnancy BMI in kg/m2, N (%) | ||||
| Less than 18.5 | 207 (3.0) | 38 (4.8) | 439 (5.2) | 150 (6.6) |
| [18.5; 25) | 3,964 (56.8) | 379 (48.3) | 4,180 (49.2) | 1,069 (46.8) |
| [25; 30) | 1,564 (22.4) | 173 (22.0) | 2,033 (23.9) | 504 (22.1) |
| [30; 35) | 566 (8.1) | 75 (9.6) | 912 (10.7) | 255 (11.2) |
| 35 and over | 327 (4.7) | 52 (6.6) | 564 (6.6) | 182 (8.0) |
| Maternal race/ethnicity, N (%) | ||||
| Non-Hispanic White | 4,917 (70.4) | 507 (64.6) | 5,004 (58.9) | 1,376 (60.3) |
| Non-Hispanic Black | 538 (7.7) | 65 (8.3) | 959 (11.3) | 139 (6.1) |
| Hispanic | 997 (14.3) | 124 (15.8) | 1,975 (23.3) | 609 (26.7) |
| Asian/Pacific Islander | 386 (5.5) | 71 (9.0) | 250 (2.9) | 59 (2.6) |
| Native American/Alaskan Native | NA | NA | 43 (0.5) | 19 (0.8) |
| Other | 139 (2.0) | 15 (1.9) | 260 (3.1) | 81 (3.5) |
| Maternal education in years, N (%) | ||||
| Less than or 13 | 1,936 (27.7) | 287 (36.6) | 3,446 (40.6) | 1,106 (48.4) |
| [13; 15] | 1,635 (23.4) | 195 (24.8) | 2,260 (26.6) | 583 (25.5) |
| 16 and over | 3,409 (48.8) | 303 (38.6) | 2,637 (31.0) | 573 (25.1) |
| First-degree relative with CL/P or CP | 31 (0.4) | 56 (7.1) | 29 (0.3) | 126 (5.5) |
| Diabetes, N (%) | 365 (5.2) | 67 (8.5) | 559 (6.6) | 204 (8.9) |
| Periconceptional folic acid supplementation, N (%) | 6,087 (87.2) | 640 (81.5) | 6,282 (74.0) | 1,654 (72.4) |
| Any smoking in first trimester, N (%) | 1,150 (16.5) | 174 (22.2) | 1,350 (15.9) | 494 (21.6) |
| Any alcohol use in first trimester, N (%) | 2,754 (39.4) | 257 (32.7) | 3,087 (36.3) | 850 (37.2) |
CL/P: cleft lip with or without cleft palate – CP: cleft palate – BMI: body mass index – NA: category not available
Note: Missing data among non-malformed infants and infants with CL/P: Slone Birth Defects Study: 423 subjects did not report their BMI, 9 subjects did not report race/ethnicity, 3 did not report years of education, 262 did not report on smoking status and 37 did not report on alcohol intake; National Birth Defects Prevention Study: 489 subjects did not report their BMI, 3 subjects did not report race/ethnicity, 172 did not report years of education, 144 did not report on smoking status.