Table 1 Baseline and perinatal characteristics of the study population

 Age (years)

33.0 (31.5, 36.0)

34.0 (31.0, 36.0)

0.793

 BMI (kg/m²)

26.11±3.44

25.74 (24.06, 28.29)

0.500

 Han, % (n)

85.88 (73)

86.36 (76)

0.927

 Nulliparity, % (n)

56.47 (48)

89.77 (79)

<0.001

 Family cardiovascular history, % (n)^a

57.65 (49)

48.86 (43)

0.247

 Low socioeconomic level, % (n)

18.82 (16)

28.41 (25)

0.138

 University education, % (n)

87.06 (74)

70.45 (62)

0.008

 Age (years)

34.8±4.3

35.7±4.1

0.165

 BMI (kg/m²)

25.77±3.34

25.32±3.48

0.386

 Han, % (n)

88.24 (75)

88.64 (78)

0.934

 Cigarette smoker, % (n)

34.12 (29)

43.18 (38)

0.221

 Family cardiovascular history, % (n)^a

57.65 (49)

53.41 (47)

0.575

 Low socioeconomic level, % (n)

5.88 (5)

13.64 (12)

0.087

 University education, % (n)

85.88 (73)

70.45 (62)

0.014

  Unexplained

-

12.50 (11)

-

  Female

-

45.45 (40)

-

  Male

-

18.18 (16)

-

  Female + male

-

23.86 (21)

-

  IVF

-

54.55 (48)

-

  ICSI

-

43.18 (38)

-

  IVF+ICSI

-

2.27 (2)

-

  1

-

25.00 (22)

-

  2

-

73.86 (65)

-

  3

-

1.14 (1)

-

 FET, % (n)

-

76.14 (67)

-

 Preeclampsia

4.71 (4)

9.09 (8)

0.256

 Gestational diabetes

23.53 (20)

18.18 (16)

0.386

 Placenta previa

2.35 (2)

4.55 (4)

0.710

 Obstetric cholestasis

0 (0)

0 (0)

1.000

 Prenatal corticoid exposure

1.18 (1)

2.27 (2)

1.000

 Gestational age at delivery (week)

39.6±1.0

39.5±0.9

0.694

 Cesarean section, % (n)

48.24 (41)

72.73 (64)

0.001

 Male, % (n)

47.06 (40)

52.27 (46)

0.493

 Birth length (cm)

51.0 (49.5, 52.0)

51.0 (50.0, 52.0)

0.559

 Birth weight (g)

3380±280

3448±316

0.138

 Admission to NICU

1.18 (1)

0 (0)

0.491

 Major neonatal morbidity^b

0 (0)

0 (0)

1.000

 Perinatal mortality

0 (0)

0 (0)

1.000