The CMH (the Corrected Midparental Height) method, in which the average parental height of 10.5 cm is the target height for boys and the average parental height of 6.5 cm is the target height for girls, has been widely used in pediatric practice. This method has been commonly used since the 1970s. The specific formula is: Boy = (father’s height + mother’s height + 13)/2±8 cm. Girl = (father’s height + mother’s height – 13)/2±8 cm. As the standard of living in China has improved significantly in recent years, many of the previous generation may have not received more timely and effective treatment due to inadequate nutrition or disease to make the height growth adequate, the adult height of children now is often higher than the genetic height. And the CMH method takes genetic factors to 100%, which is obviously unreasonable. At the same time, genetic height in recent years also found that there is a regression phenomenon, that is: both husband and wife are taller, the child genetic height will be slightly lower than the calculated, both husband and wife are shorter, genetic height will be slightly higher than the calculated. Because it is more common for taller people to find taller people to marry and shorter people to find shorter people to marry, and humans do not experience a gradual increase in height differences due to this phenomenon.
Some scholars have proposed a new way of calculating target height, the FPH (the Final Height for Parental Height) method through sufficient research, which has been verified by some domestic areas and proved to be more accurate and reasonable, and thus has now replaced the CMH method mentioned earlier.
The formula for the FPH method is: Boy = 45.99 + 0.78 x (father’s height + mother’s height) ÷ 2 ± 5.29cm. Girl = 37.85 + 0.75 x (father’s height + mother’s height) ÷ 2 ± 5.29cm. Here we need to remind you that: ① the formula is statistically processed, only about 95% of normal people are in this range, not necessarily everyone can reach.
The ±5.29cm after the calculated median value is a statistical standard deviation, which may be higher or lower than the median value for normal people, but does not mean that a perfectly normal person can add 5.29cm to their genetic height through balanced nutrition, good sleep and exercise. ③ Genetic height is only the range of adult height that a perfectly normal person should achieve, and does not mean that all children can achieve it. Do not disregard your child’s growth and development because the calculated genetic height is still acceptable. Short stature is also a disease, and from time to time, children of parents who are both taller are short, because just because the parents are taller does not mean that the child will never have a disease such as growth hormone deficiency.
It is important not to be too pessimistic when you have short parents. Familial dwarfism, which can be classified as idiopathic dwarfism at present, can be treated appropriately in most cases as long as the epiphysis is not closed, and to some extent is to improve the lifetime height. At the same time, since both parents have not undergone any examination and treatment for dwarfism in the past, it does not mean that there are certainly no diseases affecting height in the family. Some diseases can now be examined and effectively treated, and if the child also has the same disease, it is entirely possible to achieve a more desirable lifetime height through examination and treatment.
⑤ Due to the improved standard of living nowadays, sex hormones in food are inevitable from time to time, and sex hormones in health care products are even more prevalent. You can’t ignore your child’s development because he or she is still tall or high. When you are precocious, your height is often higher than that of your peers, but you will stop growing early, so your height may be shorter in the future. Once puberty is over, the growth will stop and no treatment is possible.
(6) The most accurate method of predicting adult height is through accurate assessment of bone age. Because only parental height is considered when calculating genetic height, the child’s current height and bone age at that time are not taken into account. If the bone age is greater than age, there will be less room for growth later in life and the adult height will be lower, while if the bone age is less than age, there will be more room for growth later in life and the adult height may be higher. Since bone age is the physiological age of a person, it should match the current actual age. If the difference is too large, it is often due to disease and requires prompt examination and treatment.
(7) First in Japan, and now also in Taiwan and some Western European countries, free bone age films are taken every two years for all children and adolescents during their growth period, so that abnormalities in growth and development can be detected and treated in a timely manner, which is worthy of reference for the country.