Table 1.
Maternal characteristics, obstetric and perinatal outcomes of twin pregnancies.
| Normoglycaemic n= 14,785 |
GDM n = 1088 |
OR, GDM vs. Non-DM |
Pre-Existing DM n = 83 |
OR, Pre-Existing DM vs. Non-DM |
ANOVA p Value |
|
|---|---|---|---|---|---|---|
| Age (years) | 33.6 ± 5.1 | 35.3± 5.0 | 35.1 ± 6.1 | p < 0.001 | ||
| Chronic hypertension, n (%) | 127 (0.86) | 18 (1.65) | 1.81 (1.10–2.99) p = 0.020 |
3 (3.61) | 4.09 (1.27–13.14) p = 0.018 |
|
| Dyslipidaemia, n (%) | 26 (0.18) | 2 (0.18) | 1.05 (0.25–4.44) p = 0.949 |
1 (1.20) | 7.06 (0.94–52.78) p = 0.057 |
|
| Smoking, n (%) | 583 (3.94) | 54 (4.96) | 1.40 (1.05–1.87) p = 0.002 |
3 (3.61) | 0.98 (0.31–3.11) p = 0.969 |
|
| Pre-eclampsia, n (%) | 1116 (7.55) | 124 (11.39) | 1.43 (1.17–1.74) p < 0.001 |
13 (15.66) | 2.04 (1.12–3.72) p = 0.020 |
|
| Preterm birth, n (%) | 7373 (51.84) | 566 (53.04) | 1.06 (0.94–1.21) p = 0.327 |
55 (69.62) | 2.15 (1.33–3.48) p = 0.002 |
|
| Caesarean section, n (%) | 10,072 (68.12) | 714 (65.63) | 0.82 (0.71–0.93) p = 0.002 |
61 (73.49) | 1.20 (0.73–1.97) p = 0.468 |
|
| Stillbirth, n (%) | 473 (3.20) | 26 (2.39) | 0.76 (0.51–1.14) p = 0.189 |
2 (2.41) | 0.77 (0.18–3.31) p = 0.712 |
|
| Macrosomia, n (%) | 22 (0.08) | 1 (0.05) | 0.595 (0.08–4.43) p = 0.612 |
0 (0) | 0 p = 0.966 |
|
| LGA (>90th), n (%) | 3247 (11.63) | 273 (12.95) | 1.12 (0.98–1.28) p = 0.09 |
33 (20.89) | 1.98 (1.35–2.91) p = 0.001 |
|
| SGA (<10th), n (%) | 2339 (8.37) | 202 (9.58) | 1.15 (0.99–1.34) p = 0.078 |
8 (5.06) | 0.58 (0.28–1.19) p = 0.134 |
|
| Mean birth weight (g) | 2333 ± 503 | 2336 ± 486 | 2295 ± 616 | p = 0.304 |
GDM, gestational diabetes; DM, diabetes mellitus; Non-DM, non-diabetic; LGA, large for gestational age; SGA, small for gestational age. ANOVA was used to compare age and mean birthweight among the three groups. Hypertension and dyslipidaemia OR were adjusted for maternal age and smoking habit. Pre-eclampsia, preterm birth, caesarean section, stillbirth, macrosomia, LGA and SGA OR were adjusted for maternal age, chronic hypertension, dyslipidaemia, year of delivery and smoking status. Birthweight outcomes were calculated using the total number of living newborns with weight data (27,931 normoglycaemic, 2108 GDM and 158 pre-existing DM). Preterm birth was calculated considering the cases with gestational age at delivery data (14,222 normoglycaemic, 1067 GDM, 79 pre-existing DM). The other outcomes were calculated using the total number of deliveries in each group.