Table 3. Adjusted Odds Ratios for Associations between Selected Exposures and the Risk of Hypospadias Stratified by Subtype, National Birth Defects Prevention Study, 1997-2009a.
| Variable | aOR (95% CI) for 2nd degree vs controls | aOR (95% CI) for 3rd degree vs controls | aOR (95% CI) for 3rd degree vs 2nd degreeb |
|---|---|---|---|
| Maternal age (per year) | 1.03 (1.02-1.05) | 1.07 (1.04-1.09) | 1.03 (1.0-1.05) |
| Maternal race/ethnicity | |||
| Non-Hispanic white | 1 (ref) | 1 (ref) | 1 (ref) |
| Non-Hispanic black | 0.9 (0.8-1.2) | 1.7 (1.2-2.4) | 1.5 (1.0-2.2) |
| Hispanic | 0.3 (0.2-0.3) | 0.7 (0.5-1.1) | 2.3 (1.5-3.7) |
| Asian/Pacific Islander | 0.5 (0.3-0.8) | 2.3 (1.4-3.7) | 4.3 (2.3-7.7) |
| Other | 0.6 (0.4-0.8) | 1.2 (0.7-2.2) | 2.0 (1.0-3.8) |
| Maternal education >12 years | 1.2 (1.0-1.4) | 1.0 (0.7-1.4) | 0.9 (0.6-1.2) |
| Pre-pregnancy BMI ≥30 kg/m2 | 1.0 (0.8-1.2) | 1.1 (0.8-1.5) | |
| Family history of hypospadiasc | 25.9 (13.1-51.3) | 16.4 (6.2-43.5) | 0.6 (0.3-1.2) |
| Parity | |||
| 0 | 1.7 (1.5-1.9) | 2.8 (2.2-3.7) | 1.6 (1.2-2.1) |
| ≥1 | 1 (ref) | 1 (ref) | 1 (ref) |
| Use of oral contraceptives after conceptiond | 1.0 (0.7-1.5) | 1.2 (0.6-2.3) | |
| Maternal alcohol usee | 1.1 (0.9-1.2) | 1.0 (0.8-1.3) | |
| Maternal smokingf | 0.9 (0.7-1.1) | 0.9 (0.7-1.3) | |
| Maternal cannabis usef | 0.7 (0.5-1.1) | 0.9 (0.5-1.8) | |
| Folic acid supplement usee | 1.2 (1.0-1.5) | 1.1 (0.7-1.6) | |
| Gestational diabetes mellitus | 1.2 (0.9-1.7) | 0.7 (0.4-1.3) | |
| Maternal hypertension | |||
| Untreated hypertension | 1.5 (1.2-1.8) | 2.2 (1.6-3.0) | 1.3 (1.0-1.9) |
| Early treatment | 1.2 (0.8-2.2) | 1.5 (0.6-3.5) | 1.4 (0.6-3.6) |
| Late treatment | 2.1 (1.0-4.5) | 9.0 (4.3-19.1) | 3.9 (1.7-9.0) |
| Maternal exposure to thyroxine | 1.5 (1.0-2.2) | 1.2 (0.6-2.7) | 0.9 (0.4-1.9) |
| Plurality and fertility treatment | |||
| Singleton without treatment | 1 (ref) | 1 (ref) | 1 (ref) |
| Singleton with IVF/ICSI | 1.8 (0.9-3.7) | 2.4 (0.9-6.2) | 1.1 (0.4-3.0) |
| Singleton with clomiphene citrate only | 1.2 (0.8-1.8) | 2.5 (1.4-4.5) | 2.0 (1.1-3.7) |
| Multiples without treatment | 1.5 (1.0-2.3) | 3.1 (1.8-5.5) | 1.9 (1.0-3.4) |
| Multiples with IVF/ICSI | 1.9 (1.0-3.4) | 5.2 (2.5-11.0) | 2.2 (1.1-4.7) |
| Multiples with clomiphene citrate only | 1.0 (0.3-3.1) | 7.5 (2.6-22.1) | 5.6 (1.7-17.9) |
Analyses were restricted to cases and controls with valid answers for all variables (1293 second degree cases, 324 third degree cases and 4300 controls). A full model approach was used to adjust for potential confounding.
Only included if there was an association observed for 2nd or 3rd degree hypospadias when compared to controls
Family history of hypospadias in the father, a sibling or one of the mother's previous pregnancies
Exposure measured any time in the first three months post-conception
Exposure and reference category measured between one month preconception and three months post-conception
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