Table 4.
Race-stratified Analysis of Mortality and Morbidity in Male and Female Co-twins in Mixed-Gender Twin Pairs.
| Race | Outcomes | The male twins (n, %) | The female twins (n, %) | OR (95%CI) | aOR (95%CI) |
|---|---|---|---|---|---|
| White | Fetal mortality | 725 (0.86) | 716 (0.85) | 1.02 (0.89, 1.17) | NA |
| Congenital abnormality | 1460 (1.75) | 1180 (1.41) | 1.36 (1.24, 1.49) | NA | |
| Infant mortality | 1638 (1.97) | 1457 (1.76) | 1.35 (1.21, 1.50) | 1.51 (1.34, 1.70) | |
| Neonatal mortality | 1351 (1.63) | 1217 (1.47) | 1.39 (1.21, 1.59) | 1.58 (1.36, 1.83) | |
| Low 5-minute Apgar score (<7) | 2336 (2.82) | 2175 (2.62) | 1.14 (1.05, 1.23) | 1.17 (1.08, 1.28) | |
| Assistant ventilation >30 minutes | 3390 (4.09) | 2997 (3.61) | 1.51 (1.38, 1.65) | 1.42 (1.28, 1.57) | |
| Respiratory distress syndrome | 2464 (5.6) | 2158 (4.90) | 1.63 (1.45, 1.82) | 1.51 (1.34, 1.71) | |
| Black | Fetal mortality | 374 (1.83) | 376 (1.84) | 0.99 (0.80, 1.22) | NA |
| Congenital abnormality | 340 (1.70) | 283 (1.41) | 1.34 (1.09, 1.66) | NA | |
| Infant mortality | 974 (4.90) | 898 (4.51) | 1.22 (1.05, 1.41) | 1.37 (1.17, 1.62) | |
| Neonatal mortality | 754 (3.79) | 703 (3.53) | 1.27 (1.04, 1.56) | 1.58 (1.25, 2.01) | |
| Low 5-minute Apgar score (<7) | 1193 (6.00) | 1183 (5.94) | 1.05 (0.93, 1.17) | 1.13 (0.99, 1.30) | |
| Assistant ventilation >30 minutes | 818 (4.11) | 799 (4.01) | 1.06 (0.86, 1.30) | 1.09 (0.85, 1.30) | |
| Respiratory distress syndrome | 513 (4.35) | 493 (4.18) | 1.13 (0.88, 1.46) | 1.09 (0.83, 1.44) | |
| Others | Fetal mortality | 35 (1.02) | 34 (0.99) | 1.06 (0.55, 2.05) | NA |
| Congenital abnormality | 67 (1.97) | 44 (1.29) | 2.18 (1.32, 3.61) | NA | |
| Infant mortality | 63 (1.86) | 57 (1.68) | 1.24 (0.73, 2.10) | 1.39 (0.77, 2.49) | |
| Neonatal mortality | 47 (1.39) | 44 (1.30) | 1.23 (0.59, 2.56) | 1.60 (0.62, 4.15) | |
| Low 5-minute Apgar score (<7) | 83 (2.45) | 73 (2.07) | 1.49 (0.96, 2.31) | 1.56 (0.97, 2.49) | |
| Assistant ventilation >30 minutes | 110 (3.25) | 101 (2.98) | 1.31 (0.81, 2.13) | 1.26 (0.76, 2.10) | |
| Respiratory distress syndrome | 69 (4.10) | 70 (4.16) | 0.93 (0.45, 1.93) | 1.01 (0.54, 2.30) |
OR: Odds Ratio; aOR: Odds Ratio adjusted by birth weight, birth order and methods of delivery.