Moro reflex (startle reflex) -- extends arms then bends and pulls them in toward body with a brief cry; often triggered by loud sounds or sudden movements
Palmar hand grasp -- infant closes hand and "grips" your finger
Placing -- leg extends when sole of foot is touched
Plantar grasp -- infant flexes the toes and forefoot
Rooting and sucking -- turns head in search of nipple when cheek is touched and begins to suck when nipple touches lips
Stepping and walking -- takes brisk steps when both feet are placed on a surface, with body supported
Tonic neck response -- left arm extends when infant gazes to the left, while right arm and leg flex inward, and vice versa
3 - 4 months
Better eye-muscle control allows the infant to track objects
Begins to control hand and feet actions, but these movements are not fine-tuned. The infant may begin to use both hands, working together, to accomplish tasks. The infant is still unable to coordinate the grasp, but swipes at objects to bring them closer
Increased vision allows the infant to tell objects apart from backgrounds with very little contrast (such as a button on a blouse of the same color)
Infant raises up (upper torso, shoulders, and head) with arms when lying face down (on tummy)
Neck muscles are developed enough to allow the infant to sit with support, and keep head up
Primitive reflexes have either already disappeared, or are starting to disappear
5 - 6 months
Able to sit alone, without support, for only moments at first, and then for up to 30 seconds or more
Infant begins to grasp blocks or cubes using the ulnar-palmar grasp technique (pressing the block into palm of hand while flexing or bending wrist in) but does not yet use thumb
Infant rolls from back to stomach. When on tummy, the infant can push up with arms to raise the shoulders and head and look around or reach for objects.
6 - 9 months
Crawling may begin
Infant can walk while holding an adult's hand
Infant is able to sit steadily, without support, for long periods of time
Infant learns to sit down from a standing position
Infant may pull into and keep a standing position while holding onto furniture
9 - 12 months
Infant begins to balance while standing alone
Infant takes steps holding a hand; may take few steps alone
Hearing -- begins before birth, and is mature at birth. The infant prefers the human voice.
Touch, taste, smell -- mature at birth; prefers sweet taste.
Vision -- the newborn infant can see within a range of 8 - 12 inches. Color vision develops between 4 - 6 months. By 2 months, can track moving objects up to 180 degrees, and prefers faces.
Inner ear (vestibular) senses -- the infant responds to rocking and changes of position
Crying is a very important way to communicate. By the baby's third day of life, mothers can tell their own baby's cry from that of other babies. By the first month of life, most parents can tell if their baby's cry means hunger, pain, or anger. Crying also causes a nursing mother's milk to letdown (fill the breast).
The amount of crying in the first 3 months varies in a healthy infant, from 1 - 3 hours a day. Infants who cry more than 3 hours a day are often described as having colic. Colic in infants is rarely due to a problem with the body and usually stops by 4 months of age.
Periodic breathing, in which breathing starts and stops again, is normal and is not a sign of sudden infant death syndrome ( SIDS). Some infants will vomit or spit up after each feeding, but have nothing physically wrong with them. They continue to gain weight and develop normally.
Other infants grunt and groan while making a bowel movement but produce soft, blood-free stools, and their growth and feeding are good. This is due to immature abdominal muscles used for pushing and does not need to be treated.
Sleep/wake cycles vary and do not stabilize until a baby is 3 months old. These cycles occur in random intervals of 30 - 50 minutes at birth and gradually increase as the infant matures. By age 4 months, most infants will have one 5-hour period of uninterrupted sleep per day.
Breast-fed infants will feed about every 2 hours. Formula-fed infants should be able to go 3 hours between feedings. During periods of rapid growth, they may feed more often.
You don't need to give a baby water. In fact, it could be dangerous. An infant who is drinking enough will produce 6 - 8 wet diapers in a 24-hour period. Teaching the infant to suck a pacifier or his or her own thumb provides comfort between feedings.
Safety is very important for infants. Base safety on the child's developmental stage. For example, around age 4 - 6 months, the infant may begin to roll over. Therefore, be very careful while the baby is on the changing table.
Consider the following important safety tips:
Be aware of poisons (household cleaners, cosmetics, medications, and even some plants) in your home and keep them out of your infant's reach. Use drawer and cupboard safety latches. Post the national poison control number -- 1-800-222-1222 -- near the phone.
Do not allow older infants to crawl or walk around in the kitchen while adults or older siblings are cooking. Block the kitchen off with a gate or place the infant in a playpen, highchair, or crib while others cook.
Do not drink or carry anything hot while holding the infant to avoid burns. Infants begin waving their arms and grabbing for objects at 3 - 5 months.
Do not leave an infant alone with siblings or pets. Even older siblings may not be ready to handle an emergency if it occurs. Pets, even though they may appear to be gentle and loving, may react unexpectedly to an infant's cries or grabs, or may actually smother an infant by lying too closely.
Do not leave an infant alone on a surface from which the child can wiggle or roll over and fall off.
For the first 5 months of life, always place your infant on his or her back to go to sleep. This position has been shown to reduce the risk of sudden infant death syndrome (SIDS). Once a baby can roll over by himself, the maturing nervous system greatly reduces the risk of SIDS.
Know how to handle a choking emergency in an infant by taking a certified course through the American Heart Association, the American Red Cross, or a local hospital.
Never leave small objects within an infant's reach -- infants explore their environment by putting everything they can get their hands on into their mouth.
Place your infant in a proper car seat for every car ride, no matter how short the distance. Use a car seat that faces backwards until the infant is at least 1 year old AND weighs 20 pounds, or longer if possible. Then you can safely switch to a forward facing car seat. The safest place for the infant's car seat is in the middle of the back seat. It is very important for the driver to pay attention to driving -- not playing with the infant. If an infant needs assistance, safely pull the car over to the shoulder and park before trying to help the infant.
Use gates on stairways, and block off rooms that are not "child proof" -- remember, infants may learn to crawl or scoot as early as 6 months.
CALL YOUR HEALTH CARE PROVIDER IF:
The infant does not look good, looks different from normal, or cannot be consoled by holding, rocking, or cuddling.
The infant's growth or development does not appear normal.
Your infant seems to be "losing" developmental milestones. For example, if your 9 month old was able to pull to standing, but at 12 months is no longer able to sit unsupported.
You are concerned at any time.
Kimmel SR, Ratliff-Schaub K. Growth and development. In: Rakel RE. Textbook of Family Medicine. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 23.
Feigelman S. The first year. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th Ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 108.
Jennifer K. Mannheim, ARNP, Medical Staff, Department of Psychiatry and Behavioral Health, Seattle Children's Hospital. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.