Table 1 Baseline characteristics of 1534 women with twin pregnancies
Characteristics | |
|---|---|
Maternal age, year, median [IQR] | 31.0 [29.0, 34.0] |
Gestational age, weeks, median [IQR] | 37.0 [35.0, 37.0] |
Education level, n (%) | |
Primary school or middle school | 18 (1.2) |
High school | 207 (13.5) |
College | 1309 (85.3) |
Nulliparity, n (%) | |
No | 599 (39.0) |
Yes | 935 (61.0) |
Primigravida, n (%) | |
No | 854 (55.7) |
Yes | 680 (44.3) |
Categorical PBMI by the Chinese criteria, n (%) | |
Underweight (< 18.5 kg/m2) | 245 (16.0) |
Normal (18.5–23.9 kg/m2) | 1036 (67.5) |
Overweight (24.0–27.9 kg/m2) | 198 (12.9) |
Obese (≥ 28.0 kg/m2) | 55 (3.6) |
Categorical PBMI by the WHO criteria, n (%) | |
Underweight (< 18.5 kg/m2) | 245 (16.0) |
Normal (18.5–24.9 kg/m2) | 1108 (72.2) |
Overweight (25.0–29.9 kg/m2) | 158 (10.3) |
Obese (≥ 30.0 kg/m2) | 23 (1.5) |
Use of ART, n (%) | |
No | 703 (45.8) |
Yes | 831 (54.2) |
Historical cesarean section, n (%)a | |
No | 373(62.3) |
Yes | 226(37.7) |
Family history of diabetes mellitus/hypertension, n (%) | |
No | 1298 (84.6) |
Yes | 236 (15.4) |
Pre-existing diabetes mellitus/hypertension, n (%) | |
No | 1505 (98.1) |
Yes | 29 (1.9) |
GDM, n (%) | |
No | 1157 (75.4) |
Yes | 377 (24.6) |
Gestational hypertension, n (%) | |
No | 1281 (83.5) |
Yes | 253 (16.5) |
Delivery mode, n (%) | |
Cesarean section | 1440 (93.9) |
Vaginal delivery | 94 (6.1) |
Twin type, n (%) | |
Dichorionic | 1138 (74.2) |
Monochorionic-diamniotic | 389 (25.4) |
Monoamniotic | 7 (0.5) |
Offspring sex, n (%) | |
Male | 1609 (52.4) |
Female | 1459 (47.6) |