Table 2. Crude Odds Ratios for Associations between Selected Exposures and the Risk of Hypospadias Stratified by Subtype, National Birth Defects Prevention Study, 1997- 2009.
| Variable | Male Controls (n=5183) | 2nd degree hypospadias (n=1547) | cOR (95% CI) for 2nd degree vs controls | 3rd degree hypospadias (n=389) | cOR (95% CI) for 3rd degree vs controls |
|---|---|---|---|---|---|
| Maternal age (mean [SD]) | 27.6 (6.1) | 29.3 (6.1) | 1.05 (1.04-1.06) | 29.3 (6.0) | 1.05 (1.03-1.06) |
| Maternal race/ethnicity | |||||
| Non-Hispanic white | 2976 | 1183 | 1 (ref) | 235 | 1 (ref) |
| Non-Hispanic black | 569 | 177 | 0.8 (0.7-0.9) | 60 | 1.3 (1.0-1.8) |
| Hispanic | 1242 | 101 | 0.2 (0.2-0.3) | 50 | 0.5 (0.4-0.7) |
| Asian/Pacific Islander | 146 | 34 | 0.6 (0.4-0.9) | 27 | 2.3 (1.5-3.6) |
| Other | 242 | 51 | 0.5 (0.4-0.7) | 16 | 0.8 (0.5-1.4) |
| Maternal education | |||||
| 0-12 years | 2119 | 401 | 1 (ref) | 113 | 1 (ref) |
| >12 years | 2934 | 1115 | 2.0 (1.8-2.3) | 267 | 1.7 (1.4-2.1) |
| Maternal pre-pregnancy BMI | |||||
| Non-obese (<30.0 kg/m2) | 4076 | 1248 | 1 (ref) | 303 | 1 (ref) |
| Obese (≥30.0 kg/m2) | 864 | 271 | 1.0 (0.9-1.2) | 73 | 1.1 (0.9-1.5) |
| Family history of hypospadiasa | |||||
| Yes | 10 | 85 | 30.1 (15.6-58.1) | 11 | 15.1 (6.4-35.7) |
| No | 5173 | 1462 | 1 (ref) | 378 | 1 (ref) |
| Parity | |||||
| 0 | 2048 | 774 | 1.5 (1.4-1.7) | 238 | 2.5 (2.0-3.1) |
| ≥1 | 3121 | 767 | 1 (ref) | 147 | 1 (ref) |
| Plurality | |||||
| Singletons | 5022 | 1448 | 1 (ref) | 333 | 1 (ref) |
| Multiples | 149 | 95 | 2.2 (1.7-2.9) | 56 | 5.7 (4.1-7.9) |
| Any fertility issues | |||||
| Yes | 237 | 157 | 2.4 (1.9-2.9) | 65 | 4.2 (3.1-5.7) |
| No | 4922 | 1384 | 1 (ref) | 320 | 1 (ref) |
| Fertility treatmentb | |||||
| Clomiphene citrate only | 89 | 49 | 2.0 (1.4-2.8) | 23 | 4.0 (2.5-6.4) |
| IVF/ICSI | 47 | 52 | 3.9 (2.6-5.9) | 20 | 6.5 (3.8-11.2) |
| Plurality and fertility treatment | |||||
| Singleton without treatment | 4809 | 1335 | 1 (ref) | 298 | 1 (ref) |
| Singleton with IVF/ICSI | 24 | 24 | 3.6 (2.0-6.4) | 6 | 4.0 (1.6-9.9) |
| Singleton with clomiphene citrate only | 78 | 43 | 2.0 (1.4-2.9) | 16 | 3.3 (1.9-5.7) |
| Multiples without treatment | 103 | 46 | 1.6 (1.1-2.3) | 22 | 3.4 (2.1-5.5) |
| Multiples with IVF/ICSI | 23 | 28 | 4.4 (2.5-7.6) | 14 | 9.8 (5.0-19.3) |
| Multiples with clomiphene citrate only | 11 | 6 | 2.0 (0.7-5.3) | 7 | 10.3 (4.0-26.7) |
| Use of oral contraceptives after conceptionc | |||||
| Yes | 171 | 48 | 0.9 (0.7-1.3) | 12 | 0.9 (0.5-1.7) |
| No | 4924 | 1474 | 1 (ref) | 371 | 1 (ref) |
| Maternal alcohol used | |||||
| Yes | 1875 | 661 | 1.3 (1.2-1.5) | 150 | 1.1 (0.9-1.4) |
| No | 3167 | 846 | 1 (ref) | 228 | 1 (ref) |
| Binge drinking (≥4 drinks per occasion)d | |||||
| Yes | 639 | 189 | 1.1 (0.9-1.3) | 35 | 0.8 (0.5-1.1) |
| No | 3167 | 846 | 1 (ref) | 228 | 1 (ref) |
| Maternal smokinge | |||||
| Yes | 949 | 266 | 0.9 (0.8-1.1) | 58 | 0.8 (0.6-1.1) |
| No | 4069 | 1228 | 1 (ref) | 316 | 1 (ref) |
| Maternal cannabis usee | |||||
| Yes | 210 | 42 | 0.7 (0.5-0.9) | 10 | 0.6 (0.3-1.2) |
| No | 4891 | 1482 | 1 (ref) | 372 | 1 (ref) |
| Folic acid supplement used | |||||
| Any use | 4330 | 1391 | 1.8 (1.5-2.2) | 346 | 1.7 (1.2-2.4) |
| No use | 837 | 150 | 1 (ref) | 39 | 1 (ref) |
| Maternal diabetes mellitus | |||||
| Pre-existing type I or II | 29 | 18 | 2.1 (1.2-3.8) | 1 | f |
| Gestational | 232 | 86 | 1.3 (1.0-1.6) | 19 | 1.1 (0.7-1.7) |
| No | 4768 | 1409 | 1 (ref) | 363 | 1 (ref) |
| Maternal hypertension | |||||
| Untreated hypertension | 584 | 251 | 1.6 (1.3-1.8) | 74 | 2.0 (1.5-2.6) |
| Early treatment | 67 | 29 | 1.6 (1.0-2.4) | 10 | 2.4 (1.2-4.6) |
| Late treatment | 30 | 19 | 2.3 (1.3-4.1) | 14 | 7.4 (3.9-14.0) |
| No hypertension | 4432 | 1222 | 1 (ref) | 281 | 1 (ref) |
| Maternal thyroid disorder | |||||
| Any | 118 | 62 | 1.8 (1.3-2.5) | 9 | 1.0 (0.5-2.0) |
| Thyroxine exposed | 87 | 52 | 2.0 (1.4-2.9) | 9 | 1.4 (0.7-2.8) |
| No | 5065 | 1485 | 1 (ref) | 380 | 1 (ref) |
a
Family history of hypospadias in the father, a sibling or in one of the mother's previous pregnancies
b
Reference category was no reported fertility issues
c
Exposure measured any time in the first three months post-conception
d
Exposure and reference category measured between one month preconception and three months post-conception
e
Exposures were measured between one month preconception and three months post-conception. Reference category is no exposure between three months preconception and the end of pregnancy
f
No OR was calculated for variables with <3 exposed cases