II. Physiology
- See Growth Physiology
- Birth length reflects maternal Genetics and intrauterine nutrition
- Age 6-18 month length reflects paternal Genetics
- By age 2 years, height reaches height percentile line toward mid-parental height
III. Technique: Accurate length measurement
- Precaution: Do not plot standing height on a supine chart (birth to 3 years)
- Standing height is always shorter than supine height
- Measure horizontally (lying) if child under age 2 years
- Measure vertically (standing) if child older than 2 years old
IV. Interpretation
- Age <2 years
- Shifts across height growth chart lines are normal
- Reflects shift from maternal to paternal Genetics
- Age 2-13 years
- Shifts across 2 growth chart lines are abnormal
- Growth should at least parallel the 3rd percentile line
V. Exam: Normal Height increases per year (Linear Growth Velocity)
- Birth length
- Average: birth length: 20 inches (50 cm)
- Length doubles by age 4 years
- Length triples by age 13 years
- First year growth: 9-11 inches (23-27 cm)
- Second year growth: 4-6 inches (10-14 cm)
- Third year growth: 3-4 inches (7.5 - 10 cm)
- Annual growth until Puberty: 2-3 inches (6-7 cm)
- Prepuberty growth: 2 inches (5 cm)
- Pubertal growth
- Boys: 4-6 inches (10-14 cm)
- Girls: 3-5 inches (8-12 cm)
VI. Normal Heights for boys (range: 3% to 97%)
- Age 1 year: 28-32 inches, mean: 76 cm (30 in)
- Age 2 years: 33-37 inches, mean: 88 cm (35 in)
- Age 3 years: 36-41 inches, mean: 95 cm (38 in)
- Age 4 years: 38-44 inches, mean: 103 cm (41 in)
- Age 5 years: 40-47 inches, mean: 110 cm (44 in)
- Age 6 years: 43-50 inches, mean: 116 cm (46 in)
- Age 7 years: 45-53 inches, mean: 121 cm (48 in)
- Age 8 years: 47-55 inches, mean: 127 cm (51 in)
- Age 9 years: 49-57 inches, mean: 132 cm (53 in)
- Age 10 years: 51-59 inches, mean: 137 cm (55 in)
- Age 11 years: 53-61 inches, mean: 143 cm (57 in)
- Age 12 years: 54-64 inches, mean: 150 cm (60 in)
- Age 13 years: 56-67 inches, mean: 156 cm (62 in)
- Age 14 years: 57-70 inches, mean: 163 cm (65 in)
- Age 15 years: 60-72 inches, mean: 169 cm (68 in)
- Age 16 years: 62-73 inches, mean: 173 cm (69 in)
- Age 17 years: 63-74 inches, mean: 68 inches
- Age 18 years: 177 cm (71 in)
VII. Normal Height for Girls (range: 3% to 97%)
- Birth: 18.5-21.1 inches, mean: 50 cm (20 in)
- Age 1 years: 27-31 inches, mean: 73 cm (29 in)
- Age 2 years: 32-37 inches, mean: 85 cm (34 in)
- Age 3 years: 35-40 inches, mean: 95 cm (38 in)
- Age 4 years: 38-44 inches, mean: 103 cm (41 in)
- Age 5 years: 40-47 inches, mean: 108 cm (43 in)
- Age 6 years: 43-49 inches, mean: 115 cm (46 in)
- Age 7 years: 45-52 inches, mean: 120 cm (48 in)
- Age 8 years: 47-54 inches, mean: 125 cm (50 in)
- Age 9 years: 49-56 inches, mean: 130 cm (52 in)
- Age 10 years: 50-59 inches, mean: 138 cm (55 in)
- Age 11 years: 52-62 inches, mean: 143 cm (57 in)
- Age 12 years: 54-65 inches, mean: 150 cm (60 in)
- Age 13 years: 57-66 inches, mean: 155 cm (62 in)
- Age 14 years: 58-67 inches, mean: 158 cm (63 in)
- Age 15 years: 59-68 inches, mean: 158 cm (63 in)
- Age 16 years: 59-68 inches, mean: 159 cm (64 in)
- Age 17 years: 60-68 inches, mean: 160 cm (64 in)