Table 1 Baseline characteristics of pregnant women and the outcome of neonates

maternal age

32.5 (30–35)

33 (31–35)

0.496

BMI (kg/m²)

22.05 (18.95–22.6)

20.4 (19.55–23.8)

0.671

parous women

16 (29.6)

15(39.5)

0.325

prior history of PTD

3 (5.6)

4(10.5)

0.39

The way of conception

0.067

 Natural conception

1 (1.9)

6 (15.8)

 IVF

45 (83.3)

26 (68.4)

 IUI

1 (1.9)

0 (0)

 Ovarian stimulation

7 (13)

6 (15.8)

gestational age at birth

36.14 (34.25–36.71)

37.29 (37.11–37.61)

<0.001

twin 1 weight (g)

2385 (1972.5–2550)

2632.5 (2437.5–2632.5)

<0.001

twin 2 weight (g)

2285 (2025.75–2442.5)

2620 (2450–2802.5)

0.001

twin 1 NICU admission

17(31.5)

0(0)

<0.001

twin 2 NICU admission

17(31.5)

2(5.3)

0.003

twin 1 Apgar score < 7 at 1 min

1(1.9)

0(0)

>0.999

twin 2 Apgar score < 7 at 1 min

1(1.9)

0(0)

>0.999