Your Baby's 4th Month
Learn about your baby's development at weeks 14 - 17
Baby’s Brain is Developing
Thanks to modern technology, we know more about early brain development than ever before. Empirical research has confirmed what every parent already knows intuitively: Early experiences are critical for shaping how babies think and learn.
Your baby was born with an astonishing 100 billion brain cells. These cells will be connected in networks as the brain matures. By his third birthday, your child’s brain will have formed about 1000 trillion connections. These connections are made based on Baby’s developing interests, his discoveries, and his learning about the world.
Understanding Play Habits
Watch how Baby learns from you by studying your face, your eyes, and your expressions. When Baby bats at a toy or holds a rattle, neural connections are being formed. Incredibly, these are the same connections that may one day help him hit a baseball, solve an arithmetic problem, or strum a guitar.
Observe your baby to learn what sorts of activities he enjoys. If Baby likes to lie on his back and swat at toys, lie beside him and talk about what he is doing. If he likes to be held upright, bounce him a bit and talk about what he is seeing. By supporting your baby’s natural interests, you are showing respect for his development as a unique individual.
It is never too early to begin reading to Baby. Start with board books, which are short and sturdy. Baby’s way of enjoying the book may be simply touching the cover or pages, trying to turn the pages, looking at you reading, and even tasting the book.
His interest in books may seem fleeting, but even a few seconds of reading make a lasting impression. The gentle sound of your voice, especially with sing-song or rhythmic text, the closeness of being on your lap, and the experience of touching the book are very important.
Before you know it, Baby will become more interested in the sounds you are making and the objects these sounds represent. It won’t be long before he picks up a book, hands it to you to read, and practices saying the sounds—over and over.
Touch is another way to support Baby’s early brain development while enhancing your loving relationship. Cuddling your baby or stroking his head as he falls asleep actually releases hormones that are important for his growth.
Studies show that babies who are regularly massaged gain weight faster and have deeper periods of sleep. Cortisol, a stress hormone that inhibits growth, is produced less by infants who are regularly massaged. Read more about the surprising benefits of infant massage.
While there is a huge age range as to when babies roll, around this time, some babies might roll over. Some studies suggest that babies are rolling over later because of the current emphasis on putting them to sleep on their backs as a prevention for SIDS. Still, it is important to keep putting Baby on his tummy for short periods of play time to build his muscles.
The first time a baby rolls over is usually from tummy to back. The round shape of Baby’s tummy allows for fun side-to-side rocking and then a roll over. This feat can be startling, and some babies will immediately roll over again while others may not repeat the milestone for weeks.
You can encourage rolling by placing Baby on his tummy and placing one of his favorite toys just out of reach. By stretching to get it, he may roll over again.
Baby’s first pearly whites usually don’t show themselves for a few more months, but some babies teethe as early as three or four months. Heredity is a strong factor, so look to your family history for an indication as to when your baby’s teeth might appear.
Some babies have a bulging gum or ridge for weeks before a tooth appears, while others have teeth that just seem to appear. The degree of discomfort associated with teething varies from baby to baby. Signs of teething include:
- Drooling (which may go on for weeks before the tooth appears)
- A facial rash as a result of excessive drooling
- Biting objects to satisfy achy gums
- Irritability (often expressed in the middle of the night)
- Refusal to nurse or take a bottle
- Pulling on an ear or rubbing a sore cheek
- Loose stools
More Development Help
As you’re considering your child’s development, keep in mind that all babies are unique. Whether your baby reaches milestones early or late, he has his own developmental path to follow. The dividing lines between these months are very fuzzy. If you have any concerns or questions about your baby’s development, please check with his healthcare provider.
- Use our Development Tracker to check off Baby’s 4-7 month milestones.
- Stay organized with our new-parent To-Do List.
- What’s the most common medical concern for babies this age?
Now…Let’s Take a Closer Look at Each Week
- Week 14: Understanding Cause and Effect
- Week 15: Evidence of Memory
- Week 16: Improving Vision
- Week 17: Paying Attention to Patterns
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