Factors
Group 1
n = 87 (%)
M ± SD
Group 2
n = 59 (%)
M ± SD
Group 3
n = 14 (%)
M ± SD
p-value
Group 1 
vs. Group 3
p-value
Group 2 
vs. Group 3
Age [years]
29.4 ± 6.4
29.7 ± 6.1
27.4 ± 4.8
0.31
0.22
Gestational age 
at delivery [hbd]
30.8 ± 3.9
30.9 ± 4.0
39.8 ± 1.3
< 0.001
< 0.001
Birth weight [g]
1706.2 ± 829
1749.8 ± 851
3470.0 ± 452
< 0.001
< 0.001
Parity
1
2
>3
 
 
 
 
 
52 (60)
37 (63)
12 (86)
 
 
25 (29)
19 (32)
2 (14)
0.43
0.46
10 (11)
3 (5)
0
 
 
History of PTB
14 (16)
8 (14)
1 (7)
0.38
0.49
History 
of miscarriages
9 (10)
6 (10)
1 (7)
0.71
0.72
History of stillbirth
5 (6)
2 (3)
0
0.12
0.46
Mode of delivery
Vaginal Delivery 
C-section
 
 
 
0.46
0.59
75 (86)
52 (88)
13 (93)
12 (14)
7 (12)
1 (7)
Height of the mother [cm]
163.7 ± 5.1
164.1 ± 5.2
165.4 ± 4.5
0.26
0.4
Weight 
before pregnancy [kg]
60.7 ± 10.0
62.7 ± 10.3
59.9 ± 10.1
0.8
0.43
Weight 
at delivery [kg]
68.9 ± 11.5
70.5 ± 12.2
73.9 ± 13
0.17
0.38
BMI before 
pregnancy [kg/m2]
21.7 ± 5.5
22.7 ± 5.3
21.8 ± 4.4
0.99
0.61
Temperature 
at delivery [C]
36.7 ± 0.4
36.7 ± 0.4
36.5 ± 0.4
0.14
0.064
Hemoglobin 
at delivery [mg/dl]
11.4 ± 1.1
11.4 ± 1.1
12.3 ± 1.2
0.02
0.035
White blood cells count at delivery [109/L]
13.9 ± 5.8
12.4 ± 4.1
10.7 ± 3.2
0.092
0.23
Average FHR 
on admission [b/min]
144.3 ± 9.2
144.4 ± 10.1
144.3 ± 6.6
0.98
0.95
Maternal heart rate 
on admission [b/min]
79.8 ± 8.0
79.6 ± 6.0
82.9 ± 10.8
0.23
0.15
Use of Tocolysis
40 (46)
27 (46)
2 (14)
0.018
0.022
Use of Steroids 
29 (33)
19 (32)
1 (7)
0.027
0.037
Antibiotics
28 (32)
19 (32)
3 (21)
0.41
0.42
Diabetes
 
 
 
 
 
Pregestational diabetes mellitus
0
0
1 (7)
0.012
0.039
Gestational diabetes mellitus
3 (4)
2 (3)
1 (7)
0.51
0.53
Pregnancy Hypertension
2 (2)
1 (2)
0
0.57
0.51
Smoking 
in pregnancy
14 (16)
12 (20)
2 (14)
0.86
0.61
Alcohol in pregnancy
7 (8)
5 (9)
3 (21)
0.12
0.16
Low 
socioeconomic status
9 (10)
5 (9)
0
0.093
0.14