Table 1 General characteristics of the controls, fresh embryo transfer (FRESH) and frozen embryo transfer (FET)-derived newborns, and their mothers included in the study. The SD of measures based on international growth references adjusted for gestational age at birth and gender. The mean values ± SD are presented and the significant difference between studied groups for total amount of samples is calculated by Two-Way ANOVA (P value)

 Birth weight (g)

Total

3700 ± 436

3525 ± 548

3805 ± 601

0.02

FI

3667.7 ± 412.2 (n = 100)

3443.4 ± 502.8 (n = 29)

3846.3 ± 451.4 (n = 18)

EE

3758.9 ± 473.9 (n = 57)

3595.8 ± 582.4 (n = 33)

3679.8 ± 970 (n = 6)

 Birth weight SD

Total

0.21 ± 0.8

0.1 ± 1

0.6 ± 1

NS

FI

0.1 ± 0.9 (n = 100)

− 0.1 ± 0.9 (n = 29)

0.6 ± 0.9 (n = 18)

EE

0.4 ± 0.6 (n = 57)

0.4 ± 1 (n = 33)

0.6 ± 0.9 (n = 6)

 Length (cm)

Total

51.0 ± 1.9

50.3 ± 2.3

51.1 ± 2.3

0.04

FI

51 ± 2 (n = 100)

50 ± 2 (n = 29)

51 ± 2 (n = 18)

EE

51 ± 2 (n = 57)

51 ± 2 (n = 33)

51 ± 4 (n = 6)

 Length SD

Total

− 0.1 ± 0.8

− 0.1 ± 0.8

0.1 ± 0.8

NS

FI

− 0.2 ± 0.9 (n = 100)

− 0.3 ± 0.8 (n = 29)

− 0.0 ± 0.9 (n = 18)

EE

0.2 ± 0.8 (n = 57)

0.1 ± 0.7 (n = 33)

0.6 ± 0.5 (n = 6)

 Head circumference (cm)

Total

35.5 ± 1.3 (n = 155)

35.2 ± 1.7

35.4 ± 1.9

NS

FI

35.5 ± 1 (n = 100)

34.7 ± 2 (n = 29)

35.6 ± 2 (n = 18)

EE

35.5 ± 1 (n = 55)

35.5 ± 2 (n = 33)

34.9 ± 2 (n = 6)

 Head circumference SD

Total

0.3 ± 0.8 (n = 155)

0.3 ± 1.1

0.4 ± 1.3

NS

FI

0.3 ± 0.9 (n = 100)

−0.1 ± 1 (n = 29)

0.4 ± 1.4 (n = 18)

EE

0.4 ± 0.8 (n = 55)

0.7 ± 1 (n = 33)

0.4 ± 0.7 (n = 6)

 Placenta (g)

Total

565 ± 141

514 ± 118 (n = 61)

642 ± 187

0.04

FI

626.5 ± 126.4 (n = 100)

578.4 ± 105.3 (n = 29)

687.4 ± 176 (n = 18)

EE

456.7 ± 90.5 (n = 57)

454.8 ± 97.9 (n = 32)

504.5 ± 159.6 (n = 6)

 Gestational age (weeks)

Total

40.3 ± 1.2

39.6 ± 1.4

39.8 ± 1.7

0.002

FI

40.4 ± 1 (n = 100)

39.9 ± 1.3 (n = 29)

40 ± 1 (n = 18)

EE

40 ± 1.4 (n = 57)

39.3 ± 1.4 (n = 33)

39.3 ± 3 (n = 6)

 Males

Total

53%

55%

58%

NS

FI

52%

41%

67%

EE

54%

67%

33%

 Females

Total

47%

45%

42%

NS

FI

48%

59%

33%

EE

46%

33%

67%

 Apgar score (5 min)

Total

9 ± 1 (n = 156)

9 ± 1

9 ± 1

NS

FI

9 ± 1 (n = 100)

9 ± 0.5 (n = 29)

9 ± 0.5 (n = 18)

EE

9 ± 1 (n = 56)

9 ± 0.7 (n = 33)

9 ± 0.8 (n = 6)

 Age (years)

Total

31 ± 5

34 ± 5

35 ± 4

< 0.001

FI

32 ± 5 (n = 100)

35 ± 4 (n = 29)

36 ± 3 (n = 18)

EE

29 ± 6 (n = 57)

33 ± 5 (n = 33)

33 ± 5 (n = 6)

 Parity

Total

0.7 ± 0.9

0.3 ± 0.5

0.4 ± 0.6

0.003

FI

0.6 ± 0.7 (n = 100)

0.2 ± 0.5 (n = 29)

0.3 ± 0.5 (n = 18)

EE

0.8 ± 1 (n = 57)

0.4 ± 0.6 (n = 33)

0.7 ± 0.8 (n = 6)

 BMI

Total

23.1 ± 4 (n = 155)

23.0 ± 4

24.2 ± 4

NS

FI

22.8 ± 3.5 (n = 99)

22.9 ± 3.4 (n = 29)

23.8 ± 3.4 (n = 18)

EE

23.7 ± 5 (n = 56)

23.2 ± 5 (n = 33)

25.5 ± 4.3 (n = 6)