Your Baby From 4 to 6 Months—My, How They’re Growing!

A chatty, curious, cautious, and ever-changing adventure

As a parent of an infant who’s reached at least 4 months of age, you’ve learned that any given day can bring a new sign of growth and development in your little one, let alone every new month. During months 4 through 6, you can look forward to more of the same, with some exciting new differences.

Your baby’s world

4- to 6-month feeding schedule: Your baby may be drinking 6 to 7 fl oz of formula or breast milk, 4 to 5 times a day.

New food fun: New food experiences are right around the corner! Talk to your baby's pediatrician about how to safely introduce grains, cereals, and other foods to your baby. Your pediatrician may advise waiting until your baby is 6 months old to start giving them new foods.

Twice as nice: Your baby’s weight will be approximately double their birth weight.

Your baby’s world at 4 months: establishing a fabulous foundation

You’ll notice your baby's personality becoming even more pronounced. By the end of month 4, they might be laughing out loud and trying out their babbling skills as you interact vocally with them.

They’re speaking your language—sort of

Your baby is now developing language skills and understanding—and they’re looking to you for help. Here are a few ways to encourage their advancements:

Talk to your baby often as you dress, feed, or bathe them 
Provide quiet time (turning off music and TV) 
Encourage your baby to turn their head toward sounds
Repeat sounds often and try to get your baby to mimic them

That little body needs a lot of nutrition

Whether you’ve chosen to breastfeed or formula feed, it helps to know the value of the various nutrients that work together to help strengthen baby’s immune system:  

Carbohydrates, proteins, and lipids are macronutrients that supply energy, provide cell membrane structure, and promote growth and development.
Vitamins and minerals are essential to many key metabolic processes that occur in our bodies. For example, zinc plays a vital role in the normal growth and function of many cells and tissues, including immune cells.

The importance of human milk oligosaccharides (HMOs)

Prebiotics feed good bacteria in the gut, which houses 70% of the immune system. Human milk oligosaccharides (HMOs) are a group of unique, immune-nourishing prebiotics that are associated with immune support and digestive health. HMOs are the third-most abundant solid component in breast milk.

While breast milk is the best nutrition for your baby, if you choose to formula feed, Similac^® 360 Total Care^® is our newest infant formula containing a prebiotic blend of 5 HMOs,^* previously only found together in breast milk.

^*Not from human milk.

Sleeping patterns at 4 months 

Your baby might be sleeping about 12 to 16 hours a day, including naps.¹ 
They might start rolling over and waking themselves up. If possible, give your baby a few minutes to see if they will go back to sleep on their own.

IMPORTANT: Keep thick blankets, comforters, pillows, and stuffed toys out of your baby's crib. Learn about infant sleep safety recommendations from the American Academy of Pediatrics.

Your baby’s world at 5 months: growing stronger every day

They’ll be using both hands for play and two-syllable sounds to communicate. By the end of month 5, your little one will probably have the strength to sit up with some support and pass toys from one hand to another.

At this age, your baby may start to display some wariness with strangers. Although they’ll have developed recognition of familiar faces, they might display mistrust and fear of new folks. This is normal and will pass in time. 

Complete, balanced nutrition

Your 5-month-old needs proper nutrition to grow strong. Whether you choose to breastfeed or use baby formula, they’ll need protein, fat, carbohydrates, vitamins, and minerals to support the development of bones, muscles, immune system, brain, and eyes. Below are a few important components for growth and immune system development:   

Vitamin C helps form collagen, a protein that gives structure to bones, cartilage, muscles, blood vessels, and other connective tissue. In addition, vitamin C is essential for helping the body resist infection and supporting iron absorption. 
Calcium plays an important role in bone and tooth development, blood clotting, and maintenance of healthy nerves and muscles. 
Iron is necessary for proper growth and formation of healthy blood cells and is important for brain development. Iron is part of hemoglobin, a protein that is involved in carrying and storing oxygen. 
Proteins help develop, maintain, and repair new tissues throughout the body, including muscles.

Breastfeeding is the best way to help your baby grow. If you choose to formula feed, consider Similac^® 360 Total Care^®, as it is nutrition designed for immune support, brain development, and digestive health.

Showing off their muscles and brain power 

Your baby’s muscles and brain cells are firing on all cylinders at this age. Here are 5 exercises to help your 5-month-old keep moving full speed ahead:

Encourage your baby to raise their head and push up on their arms to watch what is happening in the world around them.
Hold your baby upright under the arms. Slowly lower them until their feet touch the table, bed, or your lap to help them get a feel for standing in the future.
Help your baby learn to sit up on their own. Start by propping them up in the corner of a couch or chair, which can prevent them from falling over. Just remember, never leave your baby unattended on a chair or couch.
Try to get your baby to follow faces or bright objects with their eyes.
Help your baby pick up small toys, such as 1-inch blocks. (Keep smaller objects that can cause choking out of your baby's reach and mouth.)

Sleeping patterns at 5 months

Your baby might be sleeping 12 to 16 hours a day, including naps.¹
They might start to sit up and wake up in the process. If possible, let them try to get back to sleep on their own instead of immediately trying to provide comfort.

Your baby’s world at 6 months: half a year, whole new adventures

Your baby is laying the groundwork for speech with every coo and gaga they make. Keep talking with them. 

Your baby’s growing awareness of you as a separate person may now show itself in some separation anxiety. A good way to help reassure them that just because you’re out of sight doesn’t mean you’re gone is to play "peek-a-boo” games. 

Playtime is learning time 

Every baby develops on a different schedule, but by the end of month 6, your baby will likely be able to sit up without support and use this newfound skill to explore their world by:

Exploring textures and shapes by finding objects and putting them in their mouth. (Keep smaller objects that can cause choking out of your baby's reach.)
Picking up items by "raking" them with their fingers. (You will want to be even more careful now about what you leave around the house.)

Give them a solid start

Check with your baby's healthcare provider to determine if your baby is ready for you to introduce solid foods into their diet. When you do introduce solid foods, start them gradually and one at a time to check for allergic reactions. If you think they are having a reaction to food, immediately contact your baby's healthcare provider. If it's a severe reaction, call 911.
 
At this age, you might consider feeding these solid foods in addition to breast milk or baby formula: 

Iron-fortified baby cereals (rice, barley, oats) 
Pureed meat (fully cooked beef, pork, chicken) 
Pureed or strained fruits (bananas, pears, applesauce, peaches) 
Pureed or strained vegetables (avocados, peas, zucchini, well-cooked carrots, squash, sweet potatoes)

Find more information on Starting Solid Foods.

Sleeping patterns at 6 months

At this age, your baby will probably be sleeping through the night, waking up occasionally. 
If they aren’t growing out of waking up several times each night, talk to your baby's pediatrician about possible causes and solutions. 
During daylight hours, a 6-month-old will be wide awake and active for extended periods. Two or 3 short naps totaling 3 to 4 hours may be all they want.

Have questions about SIDS?
Learn about SIDS from the American Academy of Pediatrics.

Next month’s developments: growing at a smile a minute!

Get the whole tooth about teething, new food options, and your 7-month-old's development in next month’s article. Read ahead to Month 7.

Reference: 1. U.S. Centers for Disease Control and Prevention. About Sleep. CDC website. https://www.cdc.gov/sleep/about/index.html. Updated May 15, 2024. Accessed August 13, 2024.