### Description

The foot length can be estimated from the gestational age assuming normal development.

Wigglesworth

menstrual age (end of week)

min foot length mm

mean foot length mm

max foot length mm

8.5

3.8

4.2

4.6

9

4.2

4.6

5

10

5

5.5

6

11

6

6.9

7.8

12

7.5

9.1

10.8

13

9.8

11.4

13

14

12.3

14

15.5

15

15.2

16.8

18.5

16

18.2

19.9

21.6

17

21

23

25

18

24.8

26.8

28.2

19

28.5

30.7

33

20

31

33.3

35.7

21

32.5

35.2

38

22

36

39.5

43

23

39

42.2

45.5

24

42

45.2

48.5

25

44.5

47.7

51

26

47

50.2

53.5

27

49

52.7

56.5

28

51.5

55.2

59

29

53

57

61

30

55.5

59.2

63

31

57

61.2

65

32

59

63

67

33

61

65

69

34

63

68.2

72

35

65

70.5

75

36

69

73.5

78

37

70.5

76.5

81

38

74

78.5

83

39

76

81

86

40

77.5

82.5

87.5

Estimating Gestational Age from Foot Length

gestational age if assume mean foot length development =

= (4.3 * (10^(-10)) * ((foot length in mm)^6)) + (-7.8 * (10^(-8)) * ((foot length in mm)^5)) + (1.8 * (10^(-6)) * ((foot length in mm)^4)) + (4.041 * (10^(-4)) * ((foot length in mm)^3)) + (-0.028062 * ((foot length in mm)^2)) + (0.9353103 * (foot length in mm)) + 5.381448)

minimum gestational age from foot length =

= (7.4 * (10^(-10)) * ((foot length in mm)^6)) + (-1.9 * (10^(-7)) * ((foot length in mm)^5)) + (1.66 * (10^(-5)) * ((foot length in mm)^4)) + (-5.11 * (10^(-4)) * ((foot length in mm)^3)) + (-0.001758 * ((foot length in mm)^2)) + (0.6063543 * (foot length in mm)) + 6.1692351)

maximum gestational age from foot length =

= (-4.8 * (10^(-10)) * ((foot length in mm)^6)) + (2 * (10^(-7)) * ((foot length in mm)^5)) + (-2.4 * (10^(-5)) * ((foot length in mm)^4)) + (0.0016983 * ((foot length in mm)^3)) + (-0.059862 * ((foot length in mm)^2)) + (1.2813119 * (foot length in mm)) + 4.7547504)

Sung and Singer: Liveborn

gestational age (weeks)

toe heel (cm), mean

toe heel (cm), low

toe heel (cm), high

20

3.6

2.9

4.3

21

3.8

3.7

3.9

22

4

3.6

4.4

23

4.2

3.7

4.7

24

4.4

4.1

4.7

25

4.6

4.2

5

26

4.8

4.1

5.5

27

5

4.5

5.5

28

5.2

4.6

5.8

29

5.4

4.6

6.2

30

5.7

5

6.4

31

5.9

5.2

6.6

32

6.1

5

7.2

33

6.3

5.6

7

34

6.5

5.9

7.1

35

6.7

6.3

7.1

36

6.9

5.8

8

37

7.1

5.9

8.3

38

7.3

6.5

8.1

39

7.5

7

8

40

7.7

6.9

8.5

41

7.9

7.1

8.7

42

8.1

7

9.2

week gestation with mean foot length =

= ((foot length in cm) * 4.8427641) + 2.6382466

week gestation maximum for foot length =

= ((foot length in cm) * 4.2384628) + 3.3209954

week gestation minimum for foot length =

= ((foot length in cm) * 5.3378959) + 3.3357745

Sung and Singer: Stillborn

gestational age (weeks)

toe heel (cm), mean

toe heel (cm), low

toe heel (cm), high

20

3.3

2.7

3.9

21

3.5

2.9

4.1

22

3.8

3.4

4.2

23

4

3.5

4.5

24

4.2

3.4

5

25

4.4

3.6

5.2

26

4.7

3.8

5.6

27

4.9

3.5

6.3

28

5.1

3.9

6.3

29

5.3

4.1

6.5

30

5.6

4.9

6.3

31

5.8

5.1

6.5

32

6

5.4

6.6

33

6.2

5.8

6.6

34

6.5

5.7

7.3

35

6.7

5.8

7.6

36

6.9

6.1

7.7

37

7.2

6.3

8.1

38

7.4

6.6

8.2

39

7.6

7.1

8.1

40

7.8

7.1

8.5

41

8.1

7.3

8.9

42

8.3

7.8

8.8

week gestation with mean foot length =

(4.4061009 * (foot length in cm)) + 5.463772

week gestation maximum for foot length =

= (4.3113438 * (foot length in cm)) + 2.7325805

week gestation minimum for foot length =

= (4.2683692 * (foot length in cm)) + 9.5096891