Table 1 Characteristics of placenta and cord, overall and stratified by sex for twins born in C&W hospital (1493 pairs, n = 2986)
Overall | Male | Female | P | |
|---|---|---|---|---|
N = 1534 | N = 1452 | |||
Placenta | ||||
Chorionic villi inflammation | 264 (9.2%) | 149 (10.1%) | 115 (8.3%) | 0.09 |
Chorionitis | 208 (7.3%) | 121 (8.2%) | 87 (6.3%) | 0.04 |
Anastomosis | 252 (8.8%) | 155 (10.6%) | 96 (6.9%) | 0.01 |
Unequal placenta sharinga | 142 (32.6%) | 84 (37.2%) | 58 (27.6%) | 0.04 |
Composite of inflammation | 378 (13.2%) | 214 (14.6%) | 164 (11.8%) | 0.03 |
Composite placenta lesions | 50 (1.7%) | 33 (2.2%) | 17 (1.2%) | 0.05 |
Cord composite | 9 (0.3%) | 6 (0.4%) | < 5(< 0.3%) | 0.36 |
Placenta others | 36 (1.3%) | 20 (1.4%) | 16 (1.2%) | 0.74 |
Placenta weight, g, mean ± SD | 532.62 ± 228.97 | 536.57 ± 228.44 | 528.56 ± 229.68 | 0.46 |
Placenta length, cm, mean ± SD | 22.02 ± 5.14 | 22.16 ± 5.21 | 21.87 ± 5.06 | 0.23 |
Placenta width, cm, mean ± SD | 532.62 ± 228.97 | 17.05 ± 16.94 | 16.94 ± 3.93 | 0.55 |
Placenta thickness, cm, mean ± SD | 2.12 ± 0.47 | 2.11 ± 0.51 | 2.13 ± 0.41 | 0.37 |
Cord | ||||
Cord length, cma, mean ± SD | 27.33 ± 12.70 | 28.03 ± 13.14 | 26.57 ± 12.21 | 0.02 |
Cord distance from margin, cm, mean ± SD | 4.60 ± 2.27 | 4.58 ± 2.23 | 4.63 ± 2.31 | 0.59 |
Cord distance from membrane, cm, mean ± SD | 6.52 ± 5.14 | 6.63 ± 3.96 | 6.40 ± 4.01 | 0.41 |
Cord distance from other cord, cm, mean ± SD | 14.14 ± 8.43 | 6.63 ± 3.95 | 6.40 ± 4.01 | 0.24 |
Cord insertion type | ||||
Marginal | 1981 (69.3%) | 1029 (78.0%) | 950 (76.2%) | 0.41 |
Central | 469 (16.4%) | 228 (17.3%) | 241 (19.3%) | |
Velamentous | 118 (4.1%) | 62 (4.7%) | 56 (4.5%) | |