Growth and Development, Ages 1 to 12 Months

Topic Overview

How do babies grow and develop in the first year?

Babies change more in the first year of life than at any other time in their lives. 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. At 12 months, most babies weigh three times as much as they did at birth.
  • Cognitive development. Babies make great advances in being able to learn and remember. A baby will start to recognize loved ones and to understand that people and things still exist even when they are out of sight.
  • Emotional and social development. Babies start to show their emotions and how they feel about other people. A smile may mean that your baby is happy. A cry when you leave the room may be a protest about being left alone (called separation protest).
  • Language development. Babies quickly learn language by what is spoken around them. By about 6 weeks, your baby may have different cries for different needs, such as one to tell you it’s time to eat and another to tell you it’s time for a diaper change. By around 2 months, they coo and smile. Later they babble and chuckle. By 12 months, some babies can say simple words like "mama" or "dada," and they understand many more.
  • Sensory and motor development. During this time, a baby starts to control how he or she moves. Babies become strong enough to sit. Some will stand, and others will begin to take their first steps.

Babies usually move from one important area (or milestone) in their development to the next in a pattern. If your child has a slight delay in one area, it may not mean there is a problem. 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.

When are routine medical visits needed?

Between the ages of 1 to 12 months, a baby usually goes to the doctor at 2, 4, 6, 9, and 12 months. These routine checkups are called well-baby visits. 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 and give your baby any needed immunizations. The doctor will weigh and measure your baby to see how your baby compares to other babies of the same age. The doctor will 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's physical or emotional health. 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 physical and emotional health are 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 in healthy ways. 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 your baby. 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 for some play. And 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 between 1 and 12 months is too young to understand what is "good" and "bad" behavior. You may need to redirect your baby’s attention. For example, if your baby tries to pull the dog's tail, find a toy to get your baby’s attention and 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.

Frequently Asked Questions

Learning about growth and development:

Developmental milestones:

Seeing a doctor:

Ongoing concerns:

What to Expect

Babies usually progress in a natural, predictable sequence from one developmental milestone to the next. During the first year you will see gains in five major areas.

  • Physical development is rapid during the first year of life. Babies steadily gain weight and grow in length throughout this first year. Your baby's birth weight doubles around 6 months of age and triples by about 12 months. But remember that each child is different. Your child may be smaller or larger than other children of the same age. As long as your child continues to grow at a regular pace, your doctor will likely assure you that your baby's growth is within the normal range.
  • Cognitive development, or how the brain develops its abilities to learn and remember, progresses rapidly. Babies soon begin to recognize familiar people. As their memory develops, they gradually realize that people and objects exist even when they are out of sight, a cognitive skill called object permanence. Sensory integration evolves throughout the first year, which is the process by which a baby's brain begins to connect what is seen with what is tasted, heard, and felt.
  • Emotional and social development begins with the bonds babies form with their parents and other caregivers. When cared for in a loving and consistent way, most babies begin to engage and interact with others. By 2 months of age, your baby smiles as a way to engage you. This is called a "social smile." At about 9 months, your baby gets upset when you or another caregiver leaves. This is a normal phase that is known as separation protest. By 12 months, most babies are expressive and have formed a close attachment to their parents. They also experience some degree of separation protest.
  • Language development occurs along with brain growth. Babies start communicating with different types of cries, then progress to babbling. By 12 months, they may be able to say a few words. Most babies also understand some words by this time and begin to infer the meaning of many others. For more information, see the topic Speech and Language Development.
  • Sensory and motor skill development progresses with the continual growth of the brain, nerves, and muscles. As controlled movements become more refined, newborn reflexes gradually fade. By 4 months of age, your baby will start using the arms with purpose. For example, your baby may move the arms and squirm when excited or "swipe" at dangling objects. By 6 months of age, your baby will likely be able to sit with little or no support. Your baby learns to crawl usually by 8 months of age. Some babies will be walking by their first birthday.

Although most children reach milestones by a specific age, it's important to remember that development occurs at an individual pace. Also, many children tend to make progress in one area, such as learning to say "da-da," while another skill, like motor coordination, levels off. If your child experiences a slight delay in an area, it does not necessarily mean there is a problem. But talk to your doctor if you are concerned.

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 prematurely 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. Cognitive skills usually are first to catch up. Motor skills are often the last the catch up.

Common Concerns

Between 1 month and 12 months of age, it is very common for parents to have concerns about their baby's general well-being. Know that you likely do not 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.

Some common concerns include:

  • 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 always putting your baby to sleep on his or her back. Also consider giving your baby a pacifier at nap time and bedtime. Keep your baby's crib clear of toys and blankets. Clothing should be just enough for warmth without the risk of overheating. If possible, keep the room where your baby sleeps at a temperature that is comfortable without needing a lot of clothing or blankets. The safest place for your baby to sleep until at least 6 months of age is in your room in a separate crib or bassinet.1 For more information, see the topic Sudden Infant Death Syndrome.
  • Sleeping patterns. You may just start bragging to your friends and family how your baby is sleeping through the night when—BAM—all bets are off. 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 stay with a nap and bedtime routine. Your baby will adjust if you stay consistent. And remember, napping can be good for tired parents, too!
    Quick Tips: Getting Baby to Sleep
  • Crying. 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 parents or caregivers 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.
  • Head shape. The back of your baby's head may get a little flat from always placing him or her to sleep on the back. Usually, the flat area is not very noticeable. Your baby's head shape will return to normal after he or she can sit and crawl. But sometimes the head can become very noticeably flat. You can help prevent this by changing his or her head position regularly.
    • Make sure your baby gets "tummy time" every day. Place your baby on his or her tummy for playtime while you are watching closely. Let your baby "squirm" around, making sure that he or she can breathe easily. Tummy time helps your baby develop motor skills. These are important for helping your baby learn to move and hold his or head up.
    • 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. Holding your baby is better for all areas of development.
    • 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 each week. One week, place your baby so his or her feet are at one end of the crib. The next week, place the feet at the other end. Babies usually turn their heads away from the wall, toward the inside of a room. If your baby's crib is not against a wall, you can try moving your baby's head position more to one side while he or she is sleeping.
  • Choking. Babies love to put objects into their mouths. This habit is a choking hazard. To prevent 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. Also, choking becomes a concern as you begin introducing solid foods to your baby between 4 and 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 . Diaper rash (diaper dermatitis) is a skin irritation caused by prolonged skin wetness, friction with the diaper material, and contact with chemicals in the urine and stool. The skin may look red, raw, scalded, or burned. Even though a diaper rash is uncomfortable, normally it is not serious. Diaper rash occurs most often in babies who are at least 6 months old. Usually the rash clears up when you change diapers more often, you are careful about cleaning your baby's bottom, or you apply nonprescription ointments to the rash. For more information, see the topic Diaper Rash.
  • Sibling rivalry. 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 help your older child adjust by setting time aside for just the two of you. Also, talk about how important it is for your older child to help care for the baby. Give him or her a role in daily care, such as handing you a fresh diaper when you change your baby. Or you may put your child "in charge" of your baby's favorite toy. Your child can have a special spot for the toy and be the one who always gives it to the baby and puts it away.

Promoting Healthy Growth and Development

Babies thrive when all of their needs are fulfilled consistently and with loving care. 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, feeding, changing, and talking to your baby are the things to focus on. The rest will fall into place.

But you can always learn more about how to help your baby grow and develop in healthy ways.

To promote physical health and development:

  • Breast-feed for at least the first year of life. Introduce solid foods at the appropriate time, ideally after breast-feeding exclusively for the first 6 months.
  • 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.
  • Always put your baby to sleep on his or her back. This sleep position helps reduce the risk for sudden infant death syndrome (SIDS). For more information on SIDS, see the topic Sudden Infant Death Syndrome (SIDS).
  • Allow your baby "tummy time" while he or she is awake and you are closely watching.
  • Keep your baby safe from injury, drowning, burns, poisoning, and other dangers.
    • Buy safe baby equipment(What is a PDF document?) and use it properly. Just because a product is marketed for babies does not mean it's safe. For instance, baby walkers are not recommended.
    • Use a car seat every time your baby rides in the car.
    • Do not leave your baby alone with a pet.
    • Never leave your baby alone or in the care of an older child, even for a moment, during baths or while he or she is on a changing table.
  • Post emergency numbers near the phone. Include information about how to reach your doctor, friends, and neighbors. Keep your local Poison Control Center number handy, too.
  • Never shake your baby. Shaking your baby in anger or frustration can lead to shaken baby syndrome. Get help right away if you feel that you or another caregiver might hurt your baby.
    • Call 911 if it is an emergency.
    • Call your doctor, a friend, a relative, or a parent hotline if you are feeling overwhelmed to the point that you feel you are not able to care for your baby.

For more information, see the topic Health and Safety, Birth to Age 2.

To help promote the healthy emotional development of your baby, you can:

  • 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 appropriately 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. Some babies may experience colic, which is the extreme end of normal crying behavior that peaks at about 6 to 8 weeks of age. Using comforting techniques, such as carrying your baby with you in a front pack, may help. For more information on crying behavior, see the topic Colic or Crying, Age 3 and Younger.
  • Manage separation protest. Beginning around 6 months of age, your baby begins to feel uneasy when you go away. 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.

To help your baby gain new skills, you can:

As a parent or caregiver of children, it is also important for you to:

  • Learn and use effective parenting and discipline techniques. Do not spank or use other types of corporal punishment. A baby between 1 month and 12 months is too young to understand what is "good" and "bad" behavior. 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, find a toy to get his or her attention and move the dog to another area. You cannot "spoil" a baby between 1 month and 12 months. 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 develop into a happy and confident toddler. Parenting classes are offered in most communities. Ask your doctor or call a local hospital for more information.
  • Learn healthy techniques to manage stress and resolve conflicts. Taking care of your baby is an exciting time, but it can also be stressful. Babies need a lot of love and attention. As a parent or caregiver, you must make changes in your daily routine and some days you may simply feel overwhelmed. Also, parents often 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. You can help meet these new challenges by learning stress management skills. For example, think about ways to let others know your feelings before you reach your breaking point. Also, try new ways to relieve stress, such as exercising or listening to relaxing music. For more information, see the topic Stress Management.
  • Ask for help when you need it. Call a family member or friend to watch your baby and give you a break if you feel overwhelmed. 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.

When to Call a Doctor

Talk to your doctor any time you have concerns about your baby's:

  • Physical development. It is important to talk with your doctor if your baby's growth seems to slow significantly or if he or she is not consistently eating well.
  • Cognitive development. Cognition is the ability to learn and remember. If your baby is not becoming increasingly alert or active, talk to your doctor.
  • Emotional and social development. Talk to your doctor 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. If your baby doesn't babble as expected or respond to your voice, talk to your doctor. These may be signs of a hearing problem.
  • Sensory and motor skill development. If your baby does not consistently meet motor skill development milestones, such as purposeful rolling over or crawling, talk to your doctor.

Also see your doctor if your child has lost a skill that he or she had previously mastered.

Remember that babies reach developmental milestones at different times. Just because your child is slow in one area does not mean that he or she has a health problem or developmental delay. But it is important to talk to your doctor whenever you have concerns. Identifying problems early usually offers the best opportunities for successful treatment. Seek other information sources if you feel your concerns are not addressed or if you have any other communication problems with your child's doctor.

Your physical and mental health are also important in helping your baby reach his or her potential. Talk to your doctor if think you might be depressed or if you feel detached or unable to care for your baby in any way.

Routine Checkups

Babies between 1 month and 1 year of age should have routine checkups, sometimes called well-baby visits, at 2, 4, 6, 9, and 12 months of age. During these visits, your baby's growth and development are evaluated to see whether he or she is reaching the milestones for each specific age.

At every checkup, the doctor:

  • Looks at your baby's physical growth by measuring weight, length, and head circumference. These measurements are plotted 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 immunizations are given. For more information, see the topic Immunizations or the childhood immunization schedule.
  • 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.

In addition to the above assessments, the doctor will be especially interested in checking specific developments at your baby's:

  • 2-month checkup. 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?
  • 4-month checkup. Is your baby reaching and grasping? Does your baby try to bring objects to his or her mouth? Are crying spells shortening? Is your baby settling in with the family, and is your family enjoying the baby?
  • 6-month checkup. Is your baby able to sit? How is your baby's sensory and motor development and hand-eye coordination?
  • 9-month checkup. How is your baby eating? Is your baby able to pick up objects? Does your baby respond to his or her name?
  • 12-month checkup. Does your baby walk holding on to furniture? Does your baby enjoy playing peekaboo or patty-cake?

At the 9-month checkup, the doctor may do a test to check your child's development.

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 running list of questions(What is a PDF document?) .

Other Places To Get Help


American Academy of Pediatrics
141 Northwest Point Boulevard
Elk Grove Village, IL  60007-1098
Phone: (847) 434-4000
Fax: (847) 434-8000
Web Address:

The American Academy of Pediatrics (AAP) offers a variety of educational materials about parenting, general growth and development, immunizations, safety, disease prevention, and more. AAP guidelines for various conditions and links to other organizations are also available.

Bright Futures
P.O. Box 571272
Washington, DC  20057-1272
Phone: (202) 784-9770
Fax: (202) 784-9777
Web Address:

The Bright Futures Web site offers current information about health promotion and health care needs of infants, children, teens, families, and communities. Bright Futures is sponsored by the National Center for Education in Maternal and Child Health at Georgetown University.

Healthy Toys
117 North Division Street
Ann Arbor, MI  48104
Phone: (734) 761-3186
Fax: (734) 663-2414
Web Address:

This Web site has information about chemicals in toys. You can search by toy name or brand to see a toy's rating. You can also sign up for email updates and action alerts about toxic toys. The Ecology Center created this resource because government agencies don't require labeling or disclosure to inform consumers about the chemicals in children's products.

National Institute of Child Health and Human Development
P.O. Box 3006
Rockville, MD  20847
Phone: 1-800-370-2943
Fax: 1-866-760-5947 toll-free
TDD: 1-888-320-6942
Web Address:

The National Institute of Child Health and Human Development (NICHD) is part of the U.S. National Institutes of Health. The NICHD conducts and supports research related to the health of children, adults, and families. NICHD has information on its Web site about many health topics. And you can send specific requests to information specialists.

U.S. Consumer Product Safety Commission
4330 East West Highway
Bethesda, MD  20814
Phone: 1-800-638-2772 consumer hotline
(301) 504-7923
Fax: (301) 504-0124 and (301) 504-0025
TDD: (301) 595-7054
Web Address:

The Consumer Product Safety Commission (CPSC) is an independent federal regulatory agency. The goal of this agency is to save lives and keep families safe by reducing the risk of injuries and deaths associated with consumer products. CPSC develops safety standards, recalls products or organizes how they will be repaired, researches possible product hazards, and informs the general public about these and other safety issues. You can call their toll-free number or e-mail them to report unsafe products.

Zero to Three
2000 M Street NW
Suite 200
Washington, DC  20036
Phone: (202) 638-1144
Fax: (202) 638-0851
Web Address:

Zero to Three is a national nonprofit organization whose aim is to strengthen and support families and promote the healthy development of babies and toddlers. The organization provides information about growth and development and about health professional training. It also works to promote public awareness about the importance of giving children a healthy start and solid developmental foundation in the first three years of life.



  1. Task Force on Sudden Infant Death Syndrome, American Academy of Pediatrics (2005). The changing concept of sudden infant death syndrome: Diagnostic coding shifts, controversies regarding the sleeping environment, and new variables to consider in reducing risk. Pediatrics, 116(5): 1245–1255. Also available online:

Other Works Consulted

  • Richter SB, et al. (2006). Normal infant and childhood development. In JA McMillan et al., eds., Oski's Pediatrics: Principles and Practice, 4th ed., chap. 96, pp. 593–601. Philadelphia: Lippincott Williams and Wilkins.
  • American Academy of Pediatrics (2004). Age eight months through twelve months. In SP Shelov, RE Hannemann, eds., Caring For Your Baby and Young Child: Birth to Age 5, 4th ed., chap. 9, pp. 231–264. Elk Grove Village, IL: American Academy of Pediatrics.
  • American Academy of Pediatrics (2004). Age four months through seven months. In SP Shelov, RE Hannemann, eds., Caring For Your Baby and Young Child: Birth to Age 5, 4th ed., chap. 8, pp. 201–230. Elk Grove Village, IL: American Academy of Pediatrics.
  • American Academy of Pediatrics (2004). Age one month through three months. In SP Shelov, RE Hannemann, eds., Caring For Your Baby and Young Child: Birth to Age 5, 4th ed., chap. 7, pp. 177–200. Elk Grove Village, IL: American Academy of Pediatrics.
  • Brazelton TB (2006). Touchpoints, Birth to Three: Your Child's Emotional and Behavioral Development, 2nd ed. Cambridge, MA: Da Capo Press.
  • Goldson E, Reynolds A (2009). Child development and behavior. In WW Hay Jr et al., eds., Current Diagnosis and Treatment: Pediatrics, 19th ed., pp. 63–100. New York: McGraw-Hill.


Author Debby Golonka, MPH
Editor Susan Van Houten, RN, BSN, MBA
Associate Editor Pat Truman, MATC
Primary Medical Reviewer Michael J. Sexton, MD - Pediatrics
Specialist Medical Reviewer Louis Pellegrino, MD - Developmental Pediatrics
Last Updated April 3, 2008

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