Table 4.
Perinatal outcomes from twin pregnancies according to the presentation of the first twin, Brazil, SINASC 2011-2014.
| Perinatal outcomes | Cephalic n (%) | Non-cephalic n (%) | Cramer V |
|---|---|---|---|
| Gestational age at birth a | 0.0384 | ||
| < 28 weeks | 2 662 (3.27) | 995 (4.07) | |
| 28-31 weeks | 5 204 (6.39) | 1 947 (7.97) | |
| 32-36 weeks | 35 383 (43.47) | 10 864 (44.48) | |
| ≥ 37 weeks | 38 141 (46.86) | 10 616 (43.47) | |
| Onset of labor b | 0.0874 | ||
| Spontaneous | 24 470 (39.27) | 9 088 (45.21) | |
| Induced | 7 816 (12.54) | 1 310 (6.52) | |
| No labor | 30 021 (48.18) | 9 704 (48.27) | |
| Type of birth c | 0.1233 | ||
| Elective cesarean | 26 359 (43.20) | 8 475 (47.47) | |
| Intrapartum cesarean | 21 265 (34.85) | 7 488 (41.94) | |
| Vaginal 1st/cesarean 2nd | 981 (1.61) | 226 (1.27) | |
| Vaginal 1st/vaginal 2nd | 12 413 (20.34) | 1 663 (9.32) | |
| 5 min Apgar 1st twin d | 0.0000 | ||
| < 7 | 2 282 (2.78) | 896 (3.64) | |
| ≥ 7 | 79 726 (97.22) | 23 714 (96.36) | |
| 5 min Apgar 2nd twin e | 0.0000 | ||
| < 7 | 1 454 (2.44) | 771 (3.35) | |
| ≥ 7 | 58 081 (97.56) | 22 268 (96.65) | |
| 5 min Apgar 3rd twin f | 0.0480 | ||
| < 7 | 37 (4.99) | 12 (2.96) | |
| ≥ 7 | 704 (95.01) | 393 (97.04) | |
| 5 min Apgar 4th twin g | 0.1016 | ||
| < 7 | 3 (13.04) | 1 (6.67) | |
| ≥ 7 | 20 (86.96) | 14 (93.33) |
Missing data: (a) 24 189. (b) 47 592. (c) 51 131. (d) 23 383. (e) 18 907. (f) 399. (g) 13.