Worried about your child’s growth? – Find out with Growth Velocity
Perhaps one of the most exhilarating things about becoming parents is witnessing your children’s growing every day. It is indeed wonderful and startling how fast children grow throughout the first few years since their births, and despite this, parents cannot help but worry about whether their children are growing normally – that is if their growth velocity is sufficient.
However, knowing that a young child is within the normal height or weight range at any time is not always reassuring as this can occur in a child whose growth has been normal or even rapid for a time but then slows down significantly; or in another case, a child can be born large but has slow growth afterwards. This gives rise to the need for a measuring tool that calculates the rate of growth. Said tool is called growth velocity and will be discussed in great detail in this article.
What is growth velocity?
Available for height and weight in both boys and girls, growth velocity charts are important to evaluate the growth of a child. Height or weight velocity is a variable that represents the increase in height or weight during a fixed period and is derived from the measurement of height or weight at different times. The age-dependent changes in velocity characterizing human postnatal growth are depicted in height or weight velocity charts.
Height velocity is characterized by fast progress from birth to the child’s first year of age, followed by decreases throughout the second year. Boys tend to grow faster than girls, but their height velocities equilibrate at 7 months of age. After that, there are no outstanding differences in growth rates up to adolescence. The adolescent height spurt in boys begins at 12.5 years and reaches a peak height velocity at 14 years.
Girls instead exhibit the pubertal spurt sooner at 10.5 years and reach a peak at about 12 years. The curves for weight velocity illustrate a peak before the first year of age in both girls and boys. While the weight velocity of girls is smaller than that of boys at birth, the two figures reach an equilibrium at about 8 months of age and then the latter gradually lags behind compared with the former until adolescence.
During pubertal development, weight velocity peaks at about 14.3 years in boys and 12.9 years in girls. Generally, peak height velocity occurs at a slightly younger age than peak weight velocity.
Why is growth velocity important?
A single height measurement can merely identify children whose height is outside the normal range. On the contrary, repeated height measurements over time facilitate the calculation of a growth rate (or growth velocity) and can be used to spot abnormal growth in terms of a crossing of the height centiles, thereby leveraging the pattern of growth within the individual to detect any abnormality.
Growth velocity is a superior measure as only after altered growth rates have been sustained for a period of time do changes in actual height become apparent. A normal child tends to follow a given pattern or centile line.
While deviations in growth away from the percentile are hard to identify over short intervals using the growth curve, this can be easily done with growth velocity. It is therefore the most important reason for calculating growth velocity or the child’s growth rate.
The growth process of children
As previously mentioned, infants grow at an astoundingly fast rate. To be specific, a normal-sized newborn typically increases by 30% in length in the first 5 months and by over 50% by the first year of age. In other words, a newborn grows 25 centimeters or 10 inches on average in their first 12 months.
Between birth and 6 months, healthy infants and children grow about 2.5 centimeters or 1 inch a month; from 7 to 12 months, they grow by 1.3 centimeters or half an inch a month; and between 1 and 10 years of age, they grow by 7.6 centimeters or 3 inches a year. There can be natural variations in growth velocity in the first year mostly due to premature births, but after that, growth velocity is almost constant until puberty.
Peak height velocity
Peak height velocity is the period in which children experience the most rapid change in their stature during their adolescent growth spurt. It should be noted that the greatest change in height is actually observed during the first year of age and the adolescent growth spurt is not the fastest increase in stature during a person’s lifetime.
As a marker of maturity, the age of peak height velocity can be used for athletes to determine and adjust their training programs to maximize effectiveness. The best determinant of when to increase the training focus on strength and aerobic development is the onset of peak height velocity. For instance, while girls should begin strength training immediately after peak height velocity, boys could do the same but 12-18 months later.
How to measure peak height velocity
In order to measure peak height velocity, you should measure and plot height every 3 months from the age of 6. After noting a rapid upward deviation, you should also record the measurements of arm length and torso length to acquire a more comprehensive look at how growth is taking place. These measurements should be continued for 1-2 years after peak height velocity. The growth spurt typically lasts 1-1.5 years even though it may extend up to 5 years for slow-growing people.
When to identify growth problems
Children do not grow in a linear fashion, nor at the same rate. By monitoring height over a period of time, you may be able to identify growth problems due to hormonal imbalance, underlying disease, genetic dispositions, malnutrition, and injury. Upon early identification of a growth problem, you should immediately seek advice from a medical professional to enable proper treatment and foster healthy development. You can also compare the height measurements with height growth charts to precisely monitor development.
All in all, growth velocity charts provide a valuable tool for both parents and healthcare providers to keep track of children’s growth and promptly detect any growth problems for effective treatment. In addition, measuring peak height velocity will allow parents to support their children’s healthy development during this significant growth spurt, thereby ensuring they can reach their maximum height potential.