Table 3.
Birth weight/placental weight ratio (BW/PW) in intrauterine growth restriction (IUGR) and non-IUGR (nIUGR) monochorionic and dichorionic twins as a function of gestational age (GA) at birth.
| BW/PW, median (range) (number of cases) | ||||||
|---|---|---|---|---|---|---|
| GA at Birth (weeks) | Monochorionic, N=105 | p | Dichorionic, N=219 | p | ||
| IUGR (n=40) | nIUGR (n=65) | IUGR (n=57) | nIUGR (n=162) | |||
| ≤28 | (0) | 5.12 (3.28-7.53) (6) | - | (0) | 4.11 (3.51-6.91) (8) | - |
| 29–31 | 4.50 (4.26-4.74) (2) | 5.55 (3.20-6.40) (7) | 0.33* | 5.28 (4.72-8.86) (3) | 5.01 (4.12-7.12) (14) | 0.51* |
| 32–34 | 6.21 (3.53-8.76) (16) | 5.85 (4.60-7.04) (16) | 0.32* | 5.28 (3.73-7.92) (13) | 6.08 (4.16-9.22) (22) | 0.18* |
| ≥35 | 5.92 (4.12-8.02) (22) | 6.83 (5.12-9.93) (36) | 0.006* | 6.59 (4.60-9.29) (41) | 6.49 (3.99-9.23) (118) | 0.67* |
| All (24-38) | 5.93 (3.53-8.76) (40) | 6.20 (3.24-9.93) (65) | 0.36** | 6.38 (3.73-9.29) (57) | 6.32 (3.51-9.23) (162) | 0.68** |
| One twin with IUGR (24-38) | 5.94 (3.53- 8.77) (33) | 6.20 (3.24-9.93) (65) | 0.454* | 6.38 (3.74-9.30) (52) | 6.32 (3.51-9.23) (162) | 0.662* |
| Both twins with IUGR (24-38) | 5.27 (4.28- 7.36) (7) | 6.20 (3.24-9.93) (65) | 0.242* | 5.77 (5.25- 7.13) (5) | 6.32 (3.51-9.23) (162) | 0.659* |
*
Mann-Whitney U test;
**
Student’s t test.