Table 4.
Birth weight by the IOM and Chinese recommended GWG among twins.
| Mean (±SD)/N (%) | Chinese recommended | P | IOM recommended | P | |||||
|---|---|---|---|---|---|---|---|---|---|
| Low GWG | Normal GWG | Excess GWG | Low GWG | Normal GWG | Excess GWG | ||||
| SGA/SGA pairs | 148 (2.14) | 65 (43.92) | 58 (39.19) | 25 (16.89) | <0.001 | 58 (53.21) | 34 (31.19) | 17 (15.60) | <0.001 |
| SGA/AGA pairs | 1054 (15.22) | 285 (27.04) | 587 (55.69) | 182 (17.27) | 324 (36.73) | 410 (46.49) | 148 (16.78) | ||
| AGA/AGA pairs | 5723 (82.64) | 1279 (22.35) | 3049 (53.25) | 1395 (24.38) | 1618 (31.85) | 2270 (44.69) | 1192 (23.46) | ||
| Larger twin birth weight (g) | 2599.61 (±411.17) | 2451.62 (±450.13) | 2607.03 (±387.30) | 2731.04 (±373.40) | <0.001 | 2495.32 (±437.89) | 2629.67 (±384.40) | 2745.91 (±369.66) | <0.001 |
| Smaller twin birth weight (g) | 2311.79 (±411.21) | 2183.87 (±433.19) | 2314.52 (±397.38) | 2435.57 (±379.77) | <0.001 | 2218.16 (±429.16) | 2335.55 (±391.23) | 2446.59 (±378.67) | <0.001 |
| Sum birth weight of twins | 4910.95 (±785.09) | 4635.50 (±852.59) | 4921.55 (±745.00) | 5166.61 (±709.49) | <0.001 | 4713.48 (±833.22) | 4965.22 (±736.35) | 5192.50 (±703.98) | <0.001 |
| Both twins > = 2500 g | 2639 (55.58) | 429 (16.26) | 1409 (53.39) | 801 (30.35) | <0.001 | 584 (24.70) | 1092 (46.19) | 688 (29.10) | <0.001 |
| Both twins > = 1500 g and <2500 g | 2005 (42.23) | 637 (31.77) | 1040 (51.87) | 328 (16.36) | 697 (41.39) | 734 (43.59) | 253 (15.02) | ||
| Both twins >= 1000 g and <1500 g | 104 (2.19) | 54 (51.92) | 45 (43.27) | 5 (4.81) | 57 (62.64) | 30 (32.97) | 4 (4.40) | ||
| Twin concordance | |||||||||
| Concordant twin pairs | 5932 (85.66) | 1405 (23.69) | 3144 (53.00) | 1383 (23.31) | 0.377 | 1720 (33.10) | 2307 (44.39) | 1170 (22.51) | 0.348 |
| Discordant twin pairs | 993 (14.34) | 224 (22.56) | 550 (55.39) | 219 (22.05) | 280 (32.04) | 407 (46.57) | 187 (21.40) | ||
Abbreviations: SGA, small for gestational age; AGA, appropriate for gestational age.