Table 1.
Description and comparison of maternal and neonatal characteristics between SC-MCDA, SC-DCDA, and ART-DCDA twins.
| Items | SC-MCDA (n = 148) | SC-DCDA (n = 215) | ART-DCDA (n = 566) | Statistics | P value |
| Maternal characteristics | |||||
| Age | 24.314 | <0.001∗ | |||
| <35 years | 125 (84.5) | 173 (80.5) | 429 (75.8) | ||
| ≥35 years | 23 (15.5) | 42 (19.5) | 137 (24.2) | ||
| Mean ± SD | 30.03 ± 4.10 | 31.03 ± 3.84 | 32.20 ± 3.41 | ||
| Maternal height, cm | 162.90 ± 4.86 | 162.30 ± 4.71 | 162.16 ± 8.43 | 0.586 | 0.557∗ |
| Pre-pregnancy weight, kg | 55.10 ± 8.13 | 56.21 ± 8.72 | 56.92 ± 8.58 | 2.696 | 0.068∗ |
| Pre-pregnancy BMI | 9.639 | 0.008∗ | |||
| <18.5 kg/m2 | 25 (16.9) | 33 (15.3) | 56 (9.9) | ||
| 18.5–23.9 kg/m2 | 111 (75.0) | 152 (70.7) | 409 (72.3) | ||
| 24.0–27.9 kg/m2 | 10 (6.8) | 23 (110.7) | 86 (15.2) | ||
| ≥28.0 kg/m2 | 2 (1.3) | 7 (3.3) | 15 (2.6) | ||
| Mean ± SD | 20.73 ± 2.71 | 21.35 ± 3.24 | 21.56 ± 3.00 | ||
| Gravidity | 23.463 | 0.001† | |||
| 1 | 70 (47.3) | 103 (47.9) | 355 (62.7) | ||
| 2 | 43 (29.0) | 62 (28.9) | 115 (20.3) | ||
| 3 | 25 (16.9) | 28 (13.0) | 55 (9.7) | ||
| ≥4 | 10 (6.8) | 22 (10.2) | 41 (7.3) | ||
| Parity | 13.809 | 0.001† | |||
| 0 | 89 (60.1) | 152 (70.7) | 427 (75.4) | ||
| ≥1 | 59 (39.9) | 63 (29.3) | 139 (24.6) | ||
| Delivery mode | 5.671 | 0.059† | |||
| Natural birth | 145 (98.0) | 211 (98.1) | 564 (99.6) | ||
| Cesarean/forceps/assisted breech delivery | 3 (2.0) | 4 (1.9) | 2 (0.4) | ||
| Neonatal characteristics | |||||
| N | 296 | 430 | 1132 | ||
| Gender | 5.216 | 0.074† | |||
| Male | 128 (43.2) | 215 (50.0) | 573 (50.6) | ||
| Female | 168 (56.8) | 215 (50.0) | 559 (49.4) | ||
| Gestational age at delivery, weeks | 36.20 ± 0.95 | 36.68 ± 0.91 | 36.64 ± 0.82 | 34.483 | <0.001∗ |
| Birth weight, g | 2468.82 ± 305.99 | 2643.62 ± 316.38 | 2637.71 ± 315.13 | 36.753 | <0.001‡ |
| Birth length, cm | 47.21 ± 1.89 | 47.82 ± 1.85 | 47.89 ± 1.60 | 18.523 | <0.001∗ |
Data are presented as n (%) or mean ± SD. Bold fonts mean significance appeared. ∗Kruskal-Wallis rank test. †Chi-squared test. ‡Variance analysis test. ART-DCDA: Assisted reproductive technology dichorionic diamniotic; BMI: Body mass index; SC-DCDA: Spontaneously conceived dichorionic diamniotic; SC-MCDA: Spontaneously conceived monochorionic diamniotic; SD: Standard deviation.