Child Care: Weight, Height and Head Circumference of a Newborn Baby

The main criteria used for assessing growth are the weight, height and the head circumference of a child, which are measured periodically and plotted on a “growth chart.” (A sample chart is given at the end of this article.)

1. Weight

The normal birth weight of a term baby ranges from 2.5 to 3.8 kilos. The baby loses some weight for the initial 3-4 days, and regains its birth weight by the end of 7-10 days (it may take 14 days in case of preterm babies). So if your baby is weighing the same as at birth even after 10 days, it is normal (and not an indicator of poor breast milk supply).

After this, the baby gains on an average, approximately 20 grams/day till the child becomes 5 months of age (initially the baby may gain even 30 grams/day for the first 1 or 2 months). A simple calculation shows that it translates to 20 x 140 days = 2.8 kilos. So the baby’s birth weight doubles at 5 months.

After this, the child gains approximately 15 grams/day till the age of 1 year. It means a gain of 15 x 210 days = 3 kilos approximately. So the birth weight triples at 1 year.

It quadruples at the age of 2 years. After that it grows approximately 2 kilos/year till the age of 6 years and then 3-3.5 kilos/ year till adolescence.

Weight is ideally measured with the child in undergarments and always on the same weighing scales. I have found parents getting anxious about the weight of their child being static or even decreasing, which is not the real case because the previous weight was taken on a separate machine.

How frequently the weight of a child should be measured? There is no hard and fast rule about it, and as long as it doesn’t become an obsession with the parents, they can measure it whenever they feel like it. I won’t recommend parents to waste their time to take a healthy child to a clinic just for the sake of measuring weight. It can be done on the day of immunisation or on the day of a visit to the paediatrician.

2. Height

The final height attainable by a child is determined strongly by the genetic inheritance from the parents. After the age of 3 years, the child’s height co-relates significantly with the parental stature. It also depends on the sex of the child, girls generally being shorter than boys are, even though both are offspring of the same parents. Based on genetic factors alone, a prediction of height can be done as follows:

Girls : (father’s height – 13 cm) + (mother’s height) / 2
Boys : (mother’s height + 13 cm) + (father’s height) / 2

N.B.: A child’s predicted adult height generally falls within 5 cm above or below the height calculated by the above formula.

Since the height is so much genetically determined, there is little medical intervention can do to alter the final height. Nevertheless, parents who perceive their child as “short” want to make them taller. They will go to doctors, quacks, “height specialists” (who advertise a “guaranteed”increase in height) and try all sorls of medicines, tonics, etc along with exercises like stretching, hanging from a bar etc. to increase the height of their child. Though the intentions are noble, yet sadly, it speaks volumes of the lack of proper information amongst the parents, as also about their gullibility for “catchy” ads.

The stark and true fact is that there is no intervention that can increase the final attainable adult height of a child. (The word “final” is important here because unscrupulous and unethical use of anabolic steroids, hormones (commonly used is growth hormone) etc. can temporarily increase the height at the grave risk of reducing the final adult stature. There are also other potentially dangerous side effects associated with such modes of therapy in the hands of unqualified and untrained persons. So, unless there is a cause (e.g. a disease or a hormonal deficiency) that is causing short stature and can be treated, the final adult stature cannot be altered.

Certainly if the parents feel that their child is short, he should be taken to a doctor and be evaluated for it. Any treatment should only be given if some disease process is identified that is retarding growth and can be treated.

Normal height increment: A newborn (full term) has a length of approximately 50 cm. It becomes 1.5 times (i.e. 75 cm) at the age of 1 year, doubles (i.e. 100 cm) at the age of 4 years and triples (i.e. 150 cm) by 13 years.

Stating it in another way, the child gains approximately 4-5 inches (10 – 12 cm) during the second year and thereafter grows approximately 2 inches (5-6 cm)/ year till adolescence. Gain in height can be expected up to the age of 16 years in females and 18 years in males.

An absolute less height is less indicative of a problem than the annual increment in height. If the child is gaining 5-6 cm/year, it usually indicates no problems (even if the child is short as he may be a “late bloomer” i.e. may have a spurt at puberty). Serial measurements provide the most accurate indication of whether the physical growth of a child is progressing normally. Hence, parents should try to keep a serial and accurate record of the child’s weight, height and head circumference.

3. Head circumference

It is the third indicator of the growth of a child (mainly brain growth). It doesn’t mean that if a person has a large head, he will have more brain and thus more intelligence and vice-versa. In fact, the heads of Newton or Einstein were small (of course their head circumferences were within the normal range!).

It is usually measured a day or two after birth (to let the swelling of the scalp secondary to delivery subside, otherwise it will give a falsely higher HC). The normal HC at birth is 33-35 cm in a full term healthy baby. The HC should be measured at least every 1-2 months during the first year. A less or more than the normal increase in it is worrisome and should be investigated. The normal HC, length and weight will be much less for preterm babies.

During first 3 months, it increases 2 cm/month, so that at 3 months, it will be 39-41 cm.
During next 3 months, it increases 1 cm/month, so that at 6 months, it will be 42-44 cm.
During next 6 months, it increases 0.5 cm / month, so that at 1 year, it will be 45-47 cm.

It becomes 47-49 cm at the end of the second year and after that it gradually increases to the adult HC of 51-53 cm.

As can be inferred from above, 80-90% of the brain development occurs during the 1st two years. Therefore the measurement of HC has significance mainly up to 2 years only.

It is amazing that what we learn after 2 years throughout our whole life constitutes just 10-20% of the total human learning, 80-90% being learned in the first two years of life. Readers will find it less amazing if they sit back and think deeply that a 2 year old child has already learned the most complex and difficult tasks of life, like co-ordination, walking, running, language (and they can easily learn 2-3 languages), eating without spilling etc. If still not convinced, ask an adult who has to learn a foreign language. Let me tell you it is a difficult task and for an adult to achieve the sort of mastery (over the foreign language) that a 2-year-old child has over the mother tongue is very, very difficult, if not impossible.

TABLE FOR CALCULATING WEIGHT AND HEIGHT

WEIGHT KILOGRAMS

At birth – 2.6-3.8 kilos
3-12 months – age (months) + 9/2
1-6 years – age (years) x 2 + 8
7-12 years – age (years) x 7 – 5 / 2

HEIGHT CENTIMETRES

At birth – 50 cms
At 1 year – 75 cms
2-12 years – age (years) x 6 + 77

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