Welcome to our new series “Doctor's Advice for New Parents”! In this article, Dr.Takao Takahashi (Keio University School of Medicine’s Pediatrics Professor) answers the questions and worries of parents using his experience from being at the forefront of pediatric medicine.
This first article focuses on the first year of a child’s life, starting from birth. As with everything, the pace at which a child will grow during this time will be individual and unique. This lack of a concrete “normal” standard may be cause for worry for many mothers and fathers. So, what should you look out for, what should you be wary of, and what should you protect your child from?
Staff K, an editor for our Birth Preparation Website and mother of one, interviews Dr. Takahashi to find out.
Guidelines of Growth: Height, Weight, and Head Circumference
Staff K (hereinafter labeled K): I am truly surprised at how fast babies grow. They’re born unable to do anything, yet their neck settles and their body starts to stabilize, and by the time a year passes some babies can even walk. What can parents do to promote this development?
Dr. Takahashi: First, we should distinguish one year from 12 months. The change we feel as adults in one year may be negligible, but to a child who has only been alive for that one year, each one of those 12 months are full of change. From 5 months to 8 months, or 10 months to 12 months, there will be astonishing amounts of growth.
K: That’s true.
Dr. Takahashi: In addition, babies experience change in the form of both “growth” and “development,” which are different from each other. It is essential that fathers and mothers raise their children with both in mind.
K: I see. How are “growth” and “development” different from each other?
Dr. Takahashi: “Growth” refers to physical growth and getting bigger. Parents often worry about whether their child has gotten taller, or if they have gained weight. But another important factor is whether their head has gotten bigger too. Height, weight, and head circumference. If these three figures are within the normal range and follow the “growth curve,” you have less to worry about.
K: I often hear about height and weight, but you are saying head circumference is a key element as well.
Dr. Takahashi: Correct. This is because an increase in head circumference is closely correlated with development of the brain. However, genetics play a factor in head size, meaning most traits are already determined at birth. While weight is the most influenced by diet and environment, height and head circumference are largely decided even before birth by genetics. So as tall parents are likely to have tall children, parents with large head circumferences are likely to have children with large head circumferences.
K: I see.
Dr. Takahashi: For example, we know that the head circumferences of hungry children in developing countries are mostly not impacted by their malnutrition. In addition, fetuses that face undernutrition due to underperforming placentas will still be born with relatively normal head circumferences.
K: Wow, I didn’t know that.
Dr. Takahashi: As long as height, weight and head circumference are increasing normally, the child is making “growth.” That is what growth is. Next, I will explain development. As the body makes “growth” and becomes larger, the process of learning key functions is “development.” A newborn baby’s brain is about 10cm across, which is about 33cm in head circumference. By the baby’s first birthday, the head circumference will increase to approximately 46cm. This larger brain contains important nerve functions.
K: So development happens alongside growth.
Dr. Takahashi: Exactly. Conversely, abnormalities in growth such as head shape and size can indicate abnormalities in development. That being said, both growth and development are highly individual and unique, so there is no need to obsess over size or shape. Most things are just due to genetics.
K: And you can always consult a doctor if you’re worried.
Dr. Takahashi: Of course. Parents are generally most concerned about weight and height, but not too much about head circumference. But there is a normal range for brain size and head size as well. And while everything below the neck is obviously important, the brain is the location of nerve development. The brain determines function, and allows children to stand and talk.
K: Now that you’ve put it that way, I’m curious… What is the ideal head circumference?
Dr. Takahashi: Approximately 40cm at 4 months old is standard.
K: “40cm at 4 months” is easy to remember. What about for development?
Dr. Takahashi: First, I definitely want people to understand that every child’s development will be individual and different. That being said, one event we consider an indication in baby development is laughing out loud. If a baby has not laughed out loud by 4 months old, it may be worth looking into. On the flip side, I occasionally hear mothers saying something like “my child laughed at one month old!” but no child laughs this early either, so those are probably misunderstandings. It is quite difficult to differentiate individuality from abnormalities in development, and on top of that being able to catch any delays in said development. Perhaps these abilities showcase the true skill of a veteran pediatrician.
3 to 4 Months Old: An Important Period to Check for Development
Dr. Takahashi: Babies go from being unable to do anything to grasping key human functions during the first 12 months of life. The three main functions they learn during this time are verbal communication, walking on two feet, and holding small objects between their thumb and pointer finger.
K: If you think about it that way, it’s really amazing that they learn those key functions in just 12 months.
Dr. Takahashi: Indeed. Earlier I used the 4 month mark as a reference for head circumference, but now I would like to talk about the 3 month mark, or a quarter of a year. This mark is the “first hurdle,” and it is incredibly important to check your baby’s growth and development at this time. That is why you may notice more things being tested at health checkups during this period. Doctors will be checking for growth (height, weight, head circumference) and development (laughing out loud, etc.), to ensure that both the body and key functions are forming properly.
K: So at the 3~4 month checkup is when doctors will check for the 40cm head circumference and laughing out loud.
Dr. Takahashi: Babies also begin to follow moving objects with their eyes at 3~4 months, and their necks stabilize around the same time too, so we will check for these as well. Then, the “second hurdle” is at around 6 months old. One of the key functions at this age is to grab.
K: Like being able to hold things?
Dr. Takahashi: Yes. Around 6 months old they will start to be much more curious about their surroundings, and will reach out to grab the people and things around them. Earlier, I mentioned that one of the three main functions babies learn in the first 12 months is “holding small objects between their thumb and pointer finger.” First, they must learn to grab. This “grabbing” stage at 6 months is the halfway point.
K: So grabbing is different from holding small objects.
Dr. Takahashi: They are distinctly different. Being able to hold small objects between the thumb and the pointer finger is an advanced function unique to humans.
Monkeys are unable to hold small objects between their fingertips. Humans on the other hand develop this ability around 12 months old, and being able to pick up small bits of dirt or hair are a sign of development.
K: I didn’t know that! So, being able to grab at 6 months is a good sign.
Dr. Takahashi: Exactly. Again, please allow for some margin of error, so 2 months earlier or later for these hurdles should be no problem. Similarly, being able to stand happens around 12 months old, while walking happens around 14, but these should also be seen as estimates and not rules.
K: It’s easy getting caught up in measuring growth as a parent, even when we know every child is different.
Earlier you mentioned that verbal communication is another main function we can expect around 12 months old. What level of communication should we expect?
Dr. Takahashi: Maybe just one word with “meaning.” It doesn’t even have to be the correct word. Something like “mama” or “dada,” or “vroom” for cars. You will always be asked this at their one-year checkup.
Love your child, and they will be okay!
K: Are there things parents might do that will hinder development?
Dr. Takahashi: If you truly love your child, they will be okay. That alone is enough.
Dr. Takahashi: Yes. Of course there will be children with serious or chronic illnesses, congenital disorders or conditions. Some mothers will struggle to produce enough milk. Pediatricians and nurses are here to help you with all of these situations and more. But the vast majority of children, even if they grow at their own unique pace, are born with the genetic promise that they will grow and develop normally. You do not need to worry. Parenting should be fun, and whether you as the parent can find the joy in those first 12 months will significantly affect how you see your child in the future.
K: Finding the joy… but so many parents must be so worried about how to raise their child.
Dr. Takahashi: That’s true, but I want parents to have confidence in raising their child. Starting with the one month checkup, then 3 months, 6 months, and so forth, as long as the child is reaching each “hurdle” at their own pace, they are going to be okay. The best thing to do is not worry about every tiny little thing and have fun.
K: I hear a lot of stories about obsessing over finding the “right” way of parenting, or parents disagreeing on how to raise their children. Are these the things we should avoid?
Dr. Takahashi: I want new parents to understand that even if they pursue the “perfect” parenting, it won’t greatly affect the healthy growth and development of their child. If anything, it would be more detrimental if the parents are constantly fighting over small things. The parents’ desire to protect their child from every little thing can become too strong and overbearing. This overbearing attitude can carry from infancy to nursery, then preschool, then school and so forth until the child, who should be a source of happiness, will become more a source of worry.
K: That would be counterproductive!
Dr. Takahashi: Yes. But even so, I understand some people will still want to tell me “But Doctor, parenting is so important!” In fact, I doubt there’s many people that think raising children is purely fun. Parents are especially nervous about their first child. But most children will grow up just fine. I want parents to have confidence in this idea.
When children stand for the first time, they always smile so brightly. This moment is once in a lifetime, and even though the child won’t remember, the parents will never forget that experience. Raising a child is hard. But, I want parents to have fun and cherish this hard time and stay positive. Seeing your own child stand for the first time and smile, these moments that are so unforgettable; how many of these will you be able to cherish during these 12 months? My wish is for everyone to be able to experience as many joys like this as possible in their parenting.
Dr. Takao Takahashi
Keio University School of Medicine, Head Professor of Pediatrics, Medical Doctor specializing in General Pediatrics and Pediatric Neurology
After graduating from Keio University School of Medicine in 1982, Dr. Takahashi served in the Department of Pediatric Neurology at Harvard’s Massachusetts General Hospital and as a neurology lecturer at Harvard Medical School. He returned to Japan in 1994, and has been active as both doctor and professor at Keio University Pediatrics since. His hobby is running, and his best marathon time is 3 hours 7 minutes at the 2016 Tokyo Marathon, earning the nickname of “fastest pediatric professor in Japan.”