Table 1 Baseline demographic and clinical characteristics of maternal

Age (year)

30.99 ± 3.98

30.95 ± 4.23

30.93 ± 3.86

> 0.990

Age at menarche (year)

0.890

  ≤ 14

115(85.8)

93(87.7)

90(85.7)

  > 14

19(14.2)

13(12.3)

15(14.3)

BMI (kg/m²)

 Pre-pregnancy

21.83 ± 3.69

21.91 ± 2.75

21.65 ± 3.16

0.560

 Antenatal

26.75 ± 4.19

26.83 ± 3.69

26.98 ± 3.28

0.930

Occupation

0.036^#

 Civil servant

23 (17.0)

34 (32.0)

19 (18.0)

 Professional and technical staff

50 (37.0)

37 (35.0)

45 (43.0)

 Other

61 (46.0)

35 (33.0)

41 (39.0)

Education

0.880

 High level

31 (23.0)

21 (20.0)

24 (23.0)

 Middle level

61 (46.0)

55 (52.0)

48 (46.0)

 Low level

42 (31.0)

30 (28.0)

33 (31.0)

Smoking during pregnancy

0.640

 Yes

2 (1.0)

0 (0.0)

1 (1.0)

 No

132 (99.0)

106 (100.0)

104 (99.0)

Passive smoking before pregnancy

0.370

 Yes

28 (21.0)

15 (14.0)

21 (20.0)

 No

106 (79.0)

91 (86.0)

84 (80.0)

Drinking alcohol before pregnancy

0.670

 Yes

2 (1.0)

1 (1.80)

0 (0.0)

 No

132 (99.0)

105 (98.20)

105 (100.0)

History of chronic illness

0.019^*

 Yes

22 (16.4)

14 (13.2)

5 (4.8)

 No

112 (83.6)

92 (86.8)

100 (95.2)

Drugs or health supplements during pregnancy

0.840

 Yes

109 (81.0)

87 (82.0)

83 (79.0)

 No

25 (19.0)

19 (18.0)

22 (21.0)

Oxygen inhalation after 36 weeks of pregnancy

0.220

 Yes

23 (17.2)

10 (9.0)

14 (13.0)

 No

111 (82.8)

96 (91.0)

91 (87.0)

Pregnant mother’s blood type (ABO)

0.100

 A

27 (20.0)

28 (26.0)

31 (30.0)

 B

48 (36.0)

31 (29.0)

40 (38.0)

 AB

16 (12.0)

16 (15.0)

4 (4.0)

 O

43 (32.0)

31 (29.0)

30 (28.0)

Pregnant mother’s blood type (RH)

0.600

 RH (+)

132 (99.0)

105 (99.0)

102 (97.0)

 RH (−)

2 (1.0)

1 (1.0)

3 (3.0)

Spouse’s blood type (ABO)

0.091

 A

20 (15.0)

19 (18.0)

8 (8.0)

 B

75 (56.0)

50 (47.0)

54 (51.0)

 AB

12 (9.0)

10 (10.0)

19 (18.0)

 O

27 (20.0)

27 (25.0)

24 (23.0)

Spouse’s blood type (RH)

> 0.990

 RH (+)

133 (99.0)

106 (100.0)

105 (100.0)

 RH (−)

1 (1.0)

0 (0.0)

0 (0.0)

Gestation

0.460

 1

60 (45.0)

43 (40.60)

43 (41.0)

 2

45 (34.0)

42 (39.60)

32 (30.0)

  ≥ 3

29 (22.0)

21 (19.80)

30 (29.0)

Production

0.650

 1

81 (60.0)

66 (62.0)

59 (56.0)

  ≥ 2

53 (40.0)

40 (38.0)

46 (44.0)

Live

0.720

 1

82 (61.0)

66 (62.0)

60 (57.0)

  ≥ 2

52 (39.0)

40 (38.0)

45 (43.0)

Abortion

0.120

 0

91 (68.0)

70 (66.0)

64 (61.0)

 1

28 (21.0)

20 (19.0)

33 (31.0)

  ≥ 2

15 (11.0)

16 (15.0)

8 (8.0)

Gestational age (days)

276.46 ± 7.03

276.85 ± 6.98

277.49 ± 6.69

0.540

Oxytocin

0.820

 Yes

47 (34.0)

41 (38.0)

40 (39.0)

 No

87 (66.0)

65 (62.0)

65 (61.0)

Glucose solution without electrolytes use

0.470

 Yes

5 (4.0)

2 (2.0)

5 (5.0)

 No

129 (96.0)

104 (98.0)

100 (95.0)

Assisted reproductive technologies

0.631

 Yes

1(0.8)

1(0.9)

0(0.0)

 No

133(99.2)

105(99.1)

105(100.0)