Table 1.
Characteristics of women with twin pregnancies 2019–2021 (n = 1003)
| Characteristics | Non-GDM group (n = 785) | GDM group (n = 218) | p-value |
|---|---|---|---|
| Maternal age (year) | 32.02 ± 3.92 | 33.20 ± 3.69 | 0.000 |
| Maternal age ≥ 35 years | 201(25.6) | 83(38.1) | 0.000 |
| Pre-pregnancy BMI (kg/m2) | 21.40 ± 3.04 | 22.22 ± 3.02 | 0.000 |
| Underweight: BMI < 18.5 | 78(9.9) | 16(7.3) | 0.006 |
| Normal weight:18.5 ≤ BMI < 24 | 593(75.5) | 149(68.3) | |
| Overweight:24 ≤ BMI < 28 | 88(11.2) | 42(19.3) | |
| Obese: BMI ≥ 28 | 26(3.3) | 11(5.0) | |
| Multiparity | 123(15.7) | 28(12.8) | 0.294 |
| Assisted Reproductive Technology (ART) pregnancy | 489(62.3) | 140(64.2) | 0.603 |
| Chorionicity (dichorionic) | 601(77.8) | 172(78.9) | 0.524 |
| chronic hypertension | 9(1.1) | 5(2.3) | 0.200 |
| History of GDM | 2(0.3) | 5(2.3) | 0.007 |
| History of polycystic ovary syndrome | 20(2.5) | 9(4.1) | 0.218 |
| Family history of type II diabetes | 46(5.9) | 29(13.3) | 0.000 |
| Geography | 0.011 | ||
| Shanghai | 331(42.2) | 113(51.8) | |
| Foreign/expatriate | 454(57.8) | 105(48.2) | |
| Educational level | 0.405 | ||
| Master and above | 130(16.6) | 44(20.2) | |
| Undergraduate/Specialist | 532(67.8) | 136(62.4) | |
| High school and below | 123(15.7) | 38(17.4) | |
| Smoking | 6(0.8) | 1(0.5) | 1.000 |
| Early pregnancy | |||
| Ferritin | 90.15 ± 68.73 | 90.3 ± 71.99 | 0.854 |
| Fasting blood glucose | 4.54 ± 0.42 | 4.64 ± 0.43 | 0.000 |
| Glycated hemoglobin | 5.23 ± 0.29 | 5.35 ± 0.38 | 0.000 |
| Middle pregnancy (OGTT) | |||
| Fasting blood glucose | 4.16 ± 0.38 | 4.52 ± 0.53 | 0.000 |
| 1 h after | 7.64 ± 1.21 | 10.18 ± 1.17 | 0.000 |
| 2 h after | 6.42 ± 1.04 | 8.87 ± 1.45 | 0.000 |
| Glycated hemoglobin | 4.96 ± 0.32 | 5.14 ± 0.42 | 0.000 |
| Early and middle pregnancy (conception to OGTT) * | |||
| Weight gain (kg) | 10.20 ± 4.16 | 9.20 ± 4.12 | 0.027 |
| BMI gain (kg/m2) | 3.85 ± 1.57 | 3.53 ± 1.59 | 0.082 |
| Middle and late pregnancy (OGTT to labor) * | |||
| Weight gain (kg) | 6.87 ± 3.38 | 4.87 ± 3.76 | 0.000 |
| Weight gain per week (kg/W) | 0.58 ± 0.29 | 0.44 ± 0.47 | 0.000 |
| BMI gain per week (kg/m2/W) | 0.22 ± 0.11 | 0.17 ± 0.18 | 0.000 |
| Gestational weight gain (GWG) (kg) | 17.13 ± 6.01 | 14.08 ± 4.94 | 0.000 |