Table 1 Baseline characteristics in women with twin deliveries after 32 completed gestational weeks and with vaginal delivery of the first twin

Maternal age, years, mean (SD) median (range)

32.5 (4.8), 32.7 (17.5–51.4)

≥35 years

145 (27.5)

Nulliparous

202 (38.3)

Previous cesarean section

22 (4.2)

Body Mass Index, mean (SD) median (range)

24.2 (4.2) 23.4 (16–43)

n = 452

Body Mass Index ≥35^a

13/452 (2.8)

Smoking at first antenatal visit^a

20/436 (4.6)

Chronic hypertension

2 (0.4)

Gestational hypertension

2 (0.4)

Preeclampsia

46 (8.7)

Diabetes mellitus type 1 or 2

1 (0.2)

Gestational diabetes mellitus

6 (1.1)

Dichoriotic/diamniotic twin gestations^b

386/501 (77.0)

Monochoriotic/diamniotic twin gestations^b

115/501 (23.0)

Pregnancies with twin-twin transfusion syndrome

2 (0.4)

 Spontaneous cephalic

288 (54.6)

 Spontaneous breech

123 (23.3)

 Breech extraction

9 (1.7)

 Vacuum extraction

72 (13.7)

 Cesarean section

35 (6.6)