Table 4 Composite primary (n = 14) and secondary outcome a (n = 92) in the second twin (n = 527) in relation to birth characteristics
From: The effect of twin-to-twin delivery time intervals on neonatal outcome for second twins
Primary outcome N = 14 | No primary outcome N = 513 | Primary outcome vs no primary outcome p-value | Secondary outcome N = 92 | No secondary outcome N = 435 | Secondary outcome vs no secondary outcome p-value | |
|---|---|---|---|---|---|---|
Twin-to-twin time interval, min, mean (SD) median (range) | 37 (21) 34 (8–78) | 30 (36) 19 (2–399) | 0.028 | 37 (49) 21 (3–331) | 29 (31) 18 (2–399) | 0.13 |
Gestational age, days, mean (SD) median (range) | 256 (14) 257 (226–279) | 262 (13.7) 263 (225–286) | 0.13 | 252 (14.1) 249 (226–281) | 264 (12.6) 265 (225–286) | < 0.0001 |
Birthweight, g, mean (SD) median (range) | 2384 (462) 2515 (1230–2905) | 2680 (495) 2690 (1240–4065) | 0.028 | 2365 (523) 2325 (1560–4050) | 2737 (466) 2750 (1230–4065) | < 0.0001 |
Birthweight differenceb mean (SD) median (range) | −17.7 (14.7) − 17.4 (− 40.1–4) | − 12.7 (11.8) − 12.5 (− 56–26.8) | 0.12 | −14.9 (13.3) − 15.1 (− 46.8–26.8) | −12.4 (11.6) − 12.2 (− 56–20.8) | 0.07 |
Small for gestational age (<− 21%) | 6 (42.9) | 134 (25.5) | 0.23 | 29 (31.5) | 111 (25.6) | 0.24 |
Inter-twin birthweight discordance ≥25% | 1 (7.1) | 26 (5.1) | 0.53 | 9 (9.8) | 18 (4.1) | 0.036 |
Monochoriotic twins | 1 (7.1) | 26 (5.1) | 0.53 | 20 (21.7) | 95 (21) | 1.0 |
Assisted vaginal delivery | 2 (14.2) | 70 (13.7) | 1.0 | 13 (13.5) | 59 (13.7) | 0.87 |
Spontaneous breech delivery | 7 (50.0) | 125 (24.4) | 0.053 | 25 (27.2) | 107 (24.7) | 0.60 |
Breech extraction, including internal version | 1 (7.1) | 8 (1.6) | 0.22 | 3 (3.3) | 6 (1.4) | 0.20 |
Cesarean section, emergency | 2 (14.3) | 20 (3.9) | 0.11 | 6 (6.5) | 16 (3.7) | 0.25 |
Cesarean section, urgentc | 0 | 13 (2.5) | 1.0 | 5 (5.4) | 8 (1.8) | 0.06 |