Growth and Development, Ages 1 to 12 Months
How do babies grow and develop in the first year?
Babies change more in the first year of life than at any other time. From 1 to 12 months of age, most babies grow and develop in these main areas:
- Physical development. A baby's growth is dramatic during this first year. Babies grow taller, and their heads get bigger.
- Cognitive development. Babies make great advances in being able to learn and remember.
- Emotional and social development. Babies start to show their emotions and how they feel about other people.
- Language development. Babies quickly learn language by what is spoken around them.
- Sensory and motor development. Babies become strong enough to sit. Some will stand, and others will begin to take their first steps.
Each baby grows and gains skills at his or her own pace. It is common for a baby to be ahead in one area, such as language, but a little behind in another.
Babies who were born early or have health problems may grow and develop at a slower pace.
Why are routine medical visits needed?
Doctors recommend that babies have routine checkups (well-child visits) every 2 to 3 months from age 1 month to 12 months. These visits are important to check for problems and to make sure that your baby is growing and developing as expected.
During these visits, the doctor will:
- Do a physical exam.
- Review your child's immunization record. Needed immunizations are given or scheduled.
- Weigh and measure your baby to see how your baby compares to other babies of the same age.
- Likely ask you questions about how your family and the baby are doing.
This is a good time to talk to your doctor about any concerns you have. Between visits, write down any questions you want to ask the doctor next time.
When should you call the doctor?
Call your doctor anytime you have a concern about your baby. Be sure to call if your baby:
- Hasn't grown as expected or hasn't been eating well for some time.
- Has lost skills he or she used to have, such as crawling.
- Shows signs of hearing problems, such as not responding to your voice or to loud noises.
Your own health is also important in helping your baby grow and develop. Talk to your doctor if you think you might be depressed or if you feel like you cannot care for your baby.
How can you help your baby during the first year?
The best things for your baby are often the most basic. Loving, holding, changing diapers for, talking to, and feeding your baby are the first things to focus on.
During the first year, other ways that you can help your baby grow and learn are to:
- Respond to your baby's cries. Crying is your baby's way to tell you what he or she needs. If your baby has colic, do what you can to comfort him or her. Remember that colic is normal—and temporary. Your baby will grow out of it.
- Help your baby learn. Talking, reading, and playing are all important ways to help your baby's mind grow.
- Place your baby on his or her tummy, and play together. Also give your baby plenty of time to explore safely. This can help your baby gain the confidence to try new skills, such as crawling and walking, and to grow into a healthy toddler.
- Keep your baby safe. Always put your baby to sleep on his or her back to reduce the risk for sudden infant death syndrome (SIDS). Use a car seat every time your baby rides in a car.
- Know that your baby is curious, but set limits. A baby age 1 month to 12 months is too young to know that there are certain ways he or she should behave. You may need to redirect your baby's attention. For example, if your baby tries to pull the dog's tail, you can find a toy to get your baby's attention and then move the dog to another area.
The first year of your baby's life is an exciting time, but it can also be stressful. Some days you may feel overwhelmed. Learning what is normal for babies at this age can help you spot problems early or feel better about how your baby is doing.
Ask for help when you need it. Call a family member or friend to watch your baby. If you need a break or don't feel well, ask your doctor or local hospital for some suggestions.
Health Tools help you make wise health decisions or take action to improve your health.
What to Expect
Babies usually grow in natural, predictable steps, moving from one milestone to the next. During the first year you will see gains in five major areas:
- Physical development . Babies steadily gain weight and grow in length throughout this first year, often in growth spurts.
- Cognitive development . This means how the brain forms its abilities to learn and remember. Babies soon begin to recognize familiar people. They gradually realize that people and objects exist even when they are out of sight. They begin to connect what is seen with what is tasted, heard, and felt.
- Emotional and social development . Babies form bonds with their parents and other caregivers. When cared for in a loving and consistent way, most babies begin to engage and interact with others.
- Language development . Babies start communicating with different types of cries, then progress to babbling. For more information, see the topic Speech and Language Development.
- Sensory and motor skill development . As your baby's brain, nerves, and muscles continue to grow, controlled movements become more refined, and newborn reflexes gradually fade.
Milestones by age
Each baby grows and gains skills at his or her own pace. It's common for a baby to be ahead in one area, such as language, but a little behind in another.
By around 2 months, most babies:
- Smile as a way to engage others.
By 4 months, most babies:
- Start using their arms with purpose. For example, babies may move their arms and squirm when excited or "swipe" at dangling objects.
By 6 months, most babies:
- Have doubled their birth weight.
- Are able to sit with little or no support.
By 9 months, most babies:
- Get upset when you or another caregiver leaves.
- May have begun to crawl.
By 12 months , most babies:
- Have tripled their birth weight.
- Are expressive and have formed a close attachment to their parents.
- Understand some words and begin to figure out the meaning of many others.
- May be able to say a few words.
- May be walking.
Premature infants typically reach milestones later than others of the same age. But they are usually on schedule for their expected time of birth. For example, a baby born 2 months early might reach milestones 2 months later than a full-term baby born at the same time.
Healthy babies who were born prematurely usually reach normal developmental levels for their age by the time they are about 24 months of age. Learning and thinking skills usually are first to catch up. Motor skills are often the last to catch up.
During the first 12 months of a baby's life, it's very common for parents to have concerns about their baby's general well-being. Know that you likely don't have anything to worry about. But it is good to be aware of health, development, and safety issues to help prevent or respond to problems.
Sudden infant death syndrome (SIDS)
SIDS is the death, without a known cause, of a baby who is younger than 1 year old. Typically, a parent or other caregiver puts the baby—who seems healthy—down to sleep and returns later to find the baby has died.
SIDS is very rare, and it cannot always be prevented. But you can help prevent SIDS by taking certain steps. For instance, always put your baby to sleep on his or her back. For more information, see the topic Sudden Infant Death Syndrome (SIDS).
You may just start bragging to your friends and family how your baby is sleeping through the night when—suddenly—that's no longer true. The fact is, sleeping patterns change.
Your baby may suddenly start to cry when it's nap time or bedtime or may wake up during the night. Sometimes a baby gets too excited for sleep after he or she has mastered some new skill, such as jabbering or shaking the crib. Other times, hunger from a growth spurt, a change in routine, or not feeling well may interrupt a good sleep pattern.
Try to keep a nap and bedtime routine. Your baby will adjust if you stay consistent. And remember, napping can be good for tired parents too.
You may notice your baby's feeding patterns change during this time. Parents often wonder whether their baby is getting enough nourishment. The quality and quantity of a baby's feedings probably are sufficient if the baby is gaining weight steadily, is content most of the time, and is becoming increasingly alert and active. For more information about feeding your baby, see the topics Breastfeeding and Bottle-Feeding.
Babies cry a lot, especially in the first 2 months. Crying is your child's first way of communicating.
The amount of time your baby spends crying usually increases from birth until your baby is about 6 to 8 weeks old. After that, your baby will gradually cry less as he or she finds other ways of communicating or consoling himself or herself.
If your child is crying, try to identify the type of cry. It helps to go through a mental checklist of what might be wrong and make sure your child is safe and cared for.
As you respond to the young child's other signals (such as whimpering, facial expressions, and wiggling), the child will usually cry less. For more information, see the topic Crying, Age 3 and Younger.
Babies love to put objects into their mouths. To keep your baby from choking:
- Be careful about the size of toys he or she plays with.
- Watch out for everyday items that your baby could swallow, such as coins.
- Be careful as you begin introducing solid foods to your baby around 6 months of age. Help prevent choking on food by not giving your child round, firm foods, such as hot dogs, unless you first completely chop them into very small pieces.
Diaper rash occurs most often in babies who are 9 to 12 months old. Even though a diaper rash is uncomfortable, normally it isn't serious. Usually the rash clears up when you:
- Change diapers more often.
- Are careful about cleaning your baby's bottom.
- Apply nonprescription ointments to the rash.
For more information, see the topic Diaper Rash.
Your baby is teething when his or her first teeth break through the gums. Teething usually begins around 6 months of age. But it can start at any time between 3 months and 12 months of age. Your baby may show signs of discomfort from sore and sensitive gums, be cranky, drool, and have other mild symptoms for a few days before a tooth breaks through the gum.
For more information, see the topic Teething.
It may take a few months before an older child shows signs of jealousy of a new baby. When your child realizes that the baby is there to stay, strong emotions and behavior problems may soon follow.
You can take steps to prepare for sibling rivalry. For example, you can:
- Help your older child adjust by setting time aside for just the two of you.
- Talk about how important it is for your older child to help care for the baby.
- Give your older child a role in daily care, such as handing you a fresh diaper when you change your baby.
Beginning around 6 months of age, your baby begins to feel uneasy when you go away. Starting around 9 to 12 months of age, he or she may cry and react strongly when you leave. This is called separation anxiety, or separation protest. You can help your baby manage these emotions by making sure your child is well-rested and well-fed before you leave. It may also help to distract your baby, such as with a favorite toy.
Promoting Healthy Growth and Development
A baby goes through so many changes that it can be hard for you to keep up with all the things experts say you "should be" doing to promote healthy growth and development.
Remember that the best things for your baby are usually the simplest. Loving, holding, changing diapers for, talking to, and feeding your baby are the things to focus on.
But you can always learn more about how to help your baby grow and develop in healthy ways.
Physical health and development
- Try to breastfeed for at least the first year of life. Breast milk is the ideal food for babies.
- Learn your baby's rhythms . You will gradually get a sense of your baby's unique sleeping and eating patterns and be able to help establish a routine by about 3 months of age. But be prepared to make adjustments as needed.
Help keep your baby's head from getting too flat
. It's important to always put your baby to sleep on his or her back. But always sleeping on the back may make your baby's head a little flat. You can help keep it from getting too flat by changing his or her head position regularly.
- Allow your baby "tummy time" while he or she is awake and you are closely watching. Tummy time also helps your baby develop motor skills.
- Cuddle your baby while holding his or her head up as much as you can. Don't place your baby in car seat carriers or bouncers for long periods each day.
- Change your baby's head position during sleep at least every week. (Remember to always keep your baby on his or her back during naps and at bedtime.) A good way to make sure your baby's head rests in different positions is to switch which end of the bed you place him or her in each week. Babies usually turn their heads away from the wall, toward the inside of a room.
- Start to care for your child's teeth as soon as you see the first baby tooth (primary tooth).
- Keep your baby safe from injury, drowning, burns, poisoning, and other dangers.
- Choose child care wisely. Before you take your baby to a child care center, check the health policies of the center. Get the names of people and agencies you can talk to about the care center's safety record. For more information, see the topic Choosing Child Care.
For more information about health and safety, see the topic Health and Safety, Birth to Age 2.
Emotional health and development
- Encourage bonding . Consistently interact with and provide loving attention to your baby.
- Recognize and reinforce behaviors. For example, when interacting with your baby, encourage smiling and eye contact.
- Respond to crying. Your baby cries to communicate needs, such as feeling hungry or uncomfortable. You are not spoiling your baby by promptly responding to these cues. Use comforting techniques, like cuddling and singing.
Development of new skills
- Stimulate learning . You help promote your baby's cognitive development through emotional bonding, interaction and play, and unconditional love.
- Nurture speech and language development. Talking to, interacting with, and reading to your baby are all natural ways to promote language development. For more information, see the topic Speech and Language Development.
- Don't spank your baby or use other types of corporal (physical) punishment. A baby age 1 month to 12 months is too young to know that there are certain ways he or she should behave. Try distracting a child who is doing something wrong or something that might be dangerous. For example, if your baby tries to pull the dog's tail, you can find a toy to get his or her attention, and then move the dog to another area.
- Don't worry about "spoiling" your baby. You can't spoil a baby at this age. Hold your child, and give him or her as much love and attention as you can. Your love and patience are critical for helping your child grow into a happy and confident toddler.
Taking care of your baby is an exciting time, but it can also be stressful. Some days you may simply feel overwhelmed. Ask for help when you need it:
- Call a family member or friend to watch your baby and give you a break.
- Investigate community resources that are available to help you with child care or other needed services.
- Call a doctor or local hospital for some suggestions.
- Some communities have respite care facilities for children. A respite care facility is a place that provides temporary child care during times when you need a break.
Also, parents may find that they have a harder time communicating with each other. Feeling tired can make you more sensitive and lose patience more easily than normal. Learn coping skills to help you deal with anger and frustration. For more information, see the topic Stress Management.
When to Call a Doctor
Call 911 or other emergency services if you become so frustrated with your child that you are afraid you might cause your child physical harm.
Talk to your doctor anytime you have concerns about your baby's:
- Physical development. (For example, call if your baby's growth seems to slow significantly or if your baby isn't consistently eating well.)
- Cognitive development. (For example, call if your baby is not becoming more alert or active over time.)
- Emotional and social development. (For example, call if you are concerned about how you and your baby interact or if you feel unable to nurture or emotionally connect with your child.)
- Language development. (For example, call if your baby doesn't babble as expected or respond to your voice.)
- Sensory and motor skill development. (For example, call if your baby doesn't consistently meet motor skill milestones, such as purposeful rolling over or crawling.)
Also see your doctor if your child has lost a skill that was previously mastered.
Doctors recommend that babies have routine well-child visits every 2 to 3 months from age 1 month to 12 months. During these visits, your doctor checks your baby's growth and development to see if your baby is reaching the milestones for each specific age. During these visits, you also can discuss any concerns you have. When your baby is age 9 months, the doctor may do a developmental screening test.
At every checkup, the doctor:
- Looks at your baby's physical growth by measuring weight, length, and head circumference. These measurements are placed on a growth chart and are compared to previous and later markings to make sure your baby is growing as expected.
- Asks you about your baby's motor and sensory development, vision, and hearing. Your baby receives a thorough exam and gets immunizations.
- Assesses your baby's emotional and social development by observing his or her interactions with you. You will be asked questions about how you and the rest of the family are doing, how your baby is eating and sleeping, and whether you have noticed any changes in behavior.
The doctor will be especially interested in certain developments at specific ages. For example:
At 2 months:
- Is your baby smiling yet?
- Do you have a routine feeding schedule?
- Are you bonding with your baby?
- Is the rest of the family adjusting to the baby?
At 4 months:
- Is your baby reaching and grasping?
- Does your baby try to bring objects to his or her mouth?
- Are crying spells getting shorter?
- Is your baby settling in with the family, and is your family enjoying the baby?
At 6 months:
- Is your baby able to sit?
- How are your baby's sensory and motor development and hand-eye coordination?
At 9 months:
- How is your baby eating?
- Is your baby able to pick up objects?
- Does your baby respond to his or her name?
At 12 months
- Does your baby walk holding on to furniture?
- Does your baby enjoy playing peekaboo or patty-cake?
Routine checkups are a good time for parents to ask about what to expect in the weeks to come. You may find it helpful to keep a list of questions to ask the doctor.
Other Works Consulted
- American Academy of Pediatrics (2009). Age eight months through twelve months. In SP Shelov et al., eds., Caring For Your Baby and Young Child: Birth to Age 5, 5th ed., pp. 249–284. New York: Bantam.
- American Academy of Pediatrics (2009). Age four months through seven months. In SP Shelov et al., eds., Caring For Your Baby and Young Child: Birth to Age 5, 5th ed., pp. 217–247. New York: Bantam.
- American Academy of Pediatrics (2009). Age one month through three months. In SP Shelov et al., eds., Caring For Your Baby and Young Child: Birth to Age 5, 5th ed., pp. 193–216. New York: Bantam.
- Augustyn M, et al. (2009). Infancy and toddler years. In WB Carey et al., eds., Developmental-Behavioral Pediatrics, 4th ed., pp. 24–38. Philadelphia: Saunders Elsevier.
- Blasco PA (2011). Motor delays. In M Augustyn et al., eds., The Zuckerman Parker Handbook of Developmental and Behavioral Pediatrics for Primary Care, 3rd ed., pp. 271–276. Philadelphia: Lippincott Williams and Wilkins.
- Brazelton TB (2006). Touchpoints, Birth to Three: Your Child's Emotional and Behavioral Development, 2nd ed. Cambridge, MA: Da Capo Press.
- Ertem IO (2011). Child development. In CD Rudolph et al., eds., Rudolph's Pediatrics, 22nd ed., pp. 34–42. New York: McGraw-Hill.
- Feigelman S (2011). The first year. In RM Kliegman et al., eds., Nelson Textbook of Pediatrics, 19th ed., pp. 26–31. Philadelphia.
- Goldson E, Reynolds A (2012). Child development and behavior. In WW Hay et al., eds., Current Diagnosis and Treatment: Pediatrics, 21st ed., pp. 73–112. New York: McGraw-Hill.
- Mayes LC, et al. (2007). The infant and toddler. In A Martin, FR Volkmar, eds., Lewis's Child and Adolescent Psychiatry: A Comprehensive Textbook, 4th ed., pp. 252–261. Philadelphia: Lippincott Williams and Wilkins.
- Newman BM, Newman PR (2012). Infancy (first 24 months). In Development Through Life: A Psychosocial Approach, 11th ed., pp. 136–192. Belmont, CA: Wadsworth Cengage Learning.
Current as of: September 20, 2021
Author: Healthwise Staff
John Pope MD - Pediatrics
Kathleen Romito MD - Family Medicine
Louis Pellegrino MD - Developmental Pediatrics