Table 3 Characteristics of the in vitro fertilization (IVF) and non-IVF premature newborns with gestational age <32 weeks

*Maternal agec

28 (20–43)

29 (20–36)

0.001

*Gravidity

1

1 (1–6)

0.024

**Preeclampsia

9 (23)

28 (25)

0.7

Male/female (n)

22/18

62/51

0.9

**Multiple birth

Twins

20 (50)

13 (12)

<0.001

Triplets

10 (25)

3 (2.7)

<0.001

*Gestational age (weeks)

28 (22–31)

29 (23–31)

0.034

*Birth weight (grams)

1180 (550–2350)

1100 (380–2370)

0.2

**Intrauterine growth retardation

1 (3)

16 (14)

0.028

**Cesarean section

32 (80)

85 (75)

0.54

**Preterm premature rupture of fetal membranes

13 (33)

23 (20)

0.12

**Out born newborn

2 (5)

13 (12)

0.23

**No or prenatal maternal management

40 (100)

106 (94)

0.27

**Antenatal steroid

28 (70)

74 (36)

0.002

**Doppler

3 (8)

21 (19)

0.24

**Resuscitation

10 (25)

29 (26)

0.8

**Oligohydramnios

9 (23)

24 (21)

0.86

**Congenital anomaly, non-life-threatening/ life-threatening

1/0 (3)

6/0 (5)

0.67

**Congenital heart anomaly

4 (10)

6 (5)

0.32

*1-minute Apgar score

(0–10)

(1–9)

0.6

*5-minute Apgar score

(0–10)

(1–9)

0.9

**Respiratory distress syndrome

33 (83)

84 (79)

0.05

**Bronchopulmonary dysplasia

16 (40)

28 (25)

0.068

**ROP

Grade 1

6 (15)

5 (4)

0.1

Grade 2

2 (5)

6 (5)

Grade 3

2 (5)

3 (3)

**Intraventricular hemorrhage

Grade 1

11(28)

21 (19)

<0.001

Grade 2

7 (18)

7 (6)

Grade 3

4 (10)

3 (3)

Grade 4

3 (8)

3 (3)