Tracking your infant’s growth may be difficult if you compare your baby’s size to other children. This is because every baby grows at a different rate and many factors affect the average height.
The best way to understand your infant’s growth is by using the month-by-month chart. Luckily, you don’t have to look far for this information.
Here is a complete guide to infant growth from 0 to 3 years old.
Key Notes
- A newborn grows by one inch every month during the first six months of life
- Growth slows down after the first six months but can increase during a spurt period
- A typical growth spurt lasts for one week and causes the baby to feed more
- Your kid will reach a height of 3 ft by the third year of life
Infant Growth From Birth To 12 Months
Babies have different growth spurts during their lives, so you cannot know the exact time for the height change of your infant. However, remember the average figure is one inch per month during the initial six months of birth. The growth slows down after that to about 0.5 inches per month.
An infant born within the normal pregnancy duration will have a height of about 19.4 to 19.7 inches. The former represents the average length of female babies, while the latter displays the height of baby boys. You can primarily understand your infant’s growth by using different charts:
- WHO Growth Chart – For 0 to 2 years old babies
- CDC Growth Chart – For 2 years and older kids
Here is a table as per the WHO growth chart to help you understand your baby’s height:
1 inch = 2.54 cm
Age | Average Height Of A Boy (In Inches) | Average Height Of A Girl (In Inches) |
Birth | 19.7 | 19.4 |
1 Month | 21.5 | 21.1 |
2 Months | 23.0 | 22.5 |
3 Months | 24.2 | 23.5 |
4 Months | 25.2 | 24.5 |
5 Months | 26.0 | 25.2 |
6 Months | 26.6 | 25.9 |
7 Months | 27.2 | 26.5 |
8 Months | 27.8 | 27.1 |
9 Months | 28.4 | 27.6 |
10 Months | 28.9 | 28.2 |
11 Months | 29.3 | 28.7 |
12 Months | 29.8 | 29.1 |
Infant Growth From 12 To 23 Months
During the second year of their lives, kids grow up to four or five inches. They also gain a few more pounds due to the development of their muscular structure. So they will be slightly slimmer than they were as a baby but with higher weight.
Here is an infant growth chart for infants of 12 to 23 months:
Age | Average Height Of A Boy (In Inches) | Average Height Of A Girl (In Inches) |
12 Months | 29.8 | 29.1 |
13 Months | 30.3 | 29.6 |
14 Months | 30.8 | 30.1 |
15 Months | 31.2 | 30.5 |
16 Months | 31.6 | 31.0 |
17 Months | 32.0 | 31.4 |
18 Months | 32.4 | 31.8 |
19 Months | 32.8 | 32.2 |
20 Months | 33.2 | 32.6 |
21 Months | 33.5 | 33.0 |
22 Months | 33.9 | 33.3 |
23 Months | 34.2 | 33.7 |
Infant Growth From 2 To 3 Years
Your baby will gain significant height between two to three years because of the fast growth rate. You can expect your kid to gain about 4.4 pounds yearly until puberty. The height gain between two to three years is about 3 inches.
Another thing to remember is that the infant’s growth from this time onwards will be monitored using the CDC chart. So the unit for height differs slightly. Here is a table to help you monitor your kid’s growth from two to three years:
Age | Average Height Of A Boy | Average Height Of A Girl |
24 Months | 2 ft 10 inches | 2 ft 9.5 inches |
30 Months | 3 ft 0 inches | 2 ft 11.5 inches |
36 Months | 3 ft 1.5 inches | 3 ft 1 inch |
Your child’s adult height can also be estimated using the period of age two to three:
- Double the height of your 18-month-old daughter to know her adult height
- Double the height of your 24-month-old boy to know his adult height
Factors That Affect Infant Growth
Your child’s genes are the primary determining factor of their height and weight. However, many other things also play a role in your kid’s growth:
1. Time Of Birth
The time of birth is an essential factor to consider because it affects the development of a baby significantly. If your newborn were born prematurely, they would be underweight and smaller. This is because the development of the fetus was interrupted due to early birth.
Your infant may also have been born later than the standard 38 weeks. Such kids are mainly larger and heavier because of their extended development. So you must remember the time of birth before worrying about your baby’s size.
Typically, you should not worry about the growth of your premature infant. This is because the baby will catch up to the height of kids born in the normal time range by the age of two.
2. The Mother’s Health
The mother’s health significantly affects a baby’s growth for various reasons. Smoking during pregnancy can hinder the development of the fetus due to exposure to toxins and other harmful things. This is why your baby may be smaller and lighter than the standard newborns.
Mothers who don’t maintain their diet during pregnancy also tend to have smaller babies. This also applies to women who take drugs such as anxiety medicine during pregnancy.
Meanwhile, females who gain excessive weight during pregnancy tend to have larger babies. This also applies to mothers with gestational diabetes.
3. Feeding Method
As a parent, you will have two options for feeding after giving birth. You can breastfeed your infant and or use formula. The former options cause the newborn to grow more quickly and gain weight slowly during the first three months.
The growth rate changes after the first three months and may be slower or faster. This varies from one infant to another. However, the weight of formula-fed and breastfed kids becomes the same by the age of two. So their heights may also coincide.
4. Gender
The gender of your infant is essential when understanding the kid’s growth. This is because boys tend to have a greater height than girls. For instance, the average length of a boy during birth is 19.7 inches.
Meanwhile, your daughter will have an average length of 19.4 inches at birth. Of course, there may be discrepancies at a time because of factors such as premature or delayed birth.
5. The Infant’s Health
The infant’s health is another thing that will affect the height. Some babies are born with chronic illnesses, which may cause their growth to be slower than normal. Being affected by an infectious disease during the early years will also slow down height changes.
Disorders that prevent your infant from absorbing essential nutrients are concerning because they slow down growth. So you must maintain your kid’s diet properly to ensure they don’t suffer. Your infant’s pediatrician will be mainly helpful in helping you formulate a diet plan.
Final Words
This is everything you need to know about infant growth from birth to three years. Your baby will undergo various growth spurts that will affect the height. A one-year infant can experience the spurt during:
- 10 to 14 days
- 5 to 6 weeks
- 12 weeks
- 16 weeks
During the spurt, your infant can become fussier than usual. The kid may also want more frequent feeding sessions. An average growth spurt lasts about a week.
Your infant’s pediatrician will measure their height every visit and can help you understand the kid’s growth. So be sure to avoid missing appointments.