When describing infant development, tasks are generally categorized into the following headings: Gross motor (e.g., head control, sitting, walking), fine motor (e.g., holding a spoon, pincer grasp), sensory, language, and social development.

The physical development of the infant begins at the head, then progresses to other parts of the body (for example, sucking precedes sitting, which precedes walking).

Physical milestones:

• newborn through 2 months
  • The infant can lift and turn the head when lying on its back.
  • The neck is unable to support the head when pulled to a sitting position.
  • The hands are fisted, the arms are flexed.
  • Primitive reflexes are in full operation. These include:
    • rooting and sucking -- turns head in search for nipple when cheek is touched and begins to suck when nipple touches lips.
    • tonic neck response -- leg extends on side of head direction, flexion occurs in opposite arm and leg.
    • palmar hand grasp -- closure over finger.
    • plantar grasp -- flexion of toe and forefoot.
    • Babinski -- toes fan when sole of foot is stroked.
    • Moro -- extension and abduction of the arms followed by flexion and adduction.
    • placing -- leg extends when sole of foot is stimulated.
    • stepping and walking -- takes brisk steps when both feet placed on a surface, with body supported.
• 3 through 4 months
  • Primitive reflexes have either already disappeared, or are in the process of doing so.
  • Hand and feet actions begin to come under willed control, but are by no means fine-tuned. The infant may begin to use both hands, working together, to accomplish desired effects. The infant is still unable to coordinate the grasp, but swipes at objects to bring them closer to self.
  • The infant raises self (upper torso, shoulders, and head) with arms when lying face down (prone).
  • Neck muscles are developed enough to allow the infant to sit, with support, and keep it's head up.
  • Enhanced eye muscular control allows the infant to track objects.
  • Increased acuity of vision allows the infant to discriminate objects from backgrounds with minimal contrast (such as a button on a blouse of the same color).
• 5 through 6 months
  • The infant begins to grasp blocks or cubes using ulnar-palmar grasp technique (presses block into palm of hand while flexing or bending wrist in). Does not yet use thumb opposition.
  • The infant rolls from back to stomach (prone position). When prone, the infant can push up with arms to raise the shoulders and head above surface and look around or reach for objects.
  • Able to sit alone, without support, for only moments initially and then up to 30 seconds or more.
• 6 through 9 months
  • The infant able to sit steadily, without support, for long periods of time.
  • The infant may pull self into and maintain a standing position while holding onto furniture.
  • The infant can walk while holding the hand of an adult.
  • The infant learns to sit down from a standing position.
• 9 through 12 months
  • The infant begins to balance while standing alone.
  • The infant takes steps and begins to walk alone.

SENSORY DEVELOPMENT

• Vision -- the infant can see objects within a range of 8 to 12 inches, has excellent color vision, can track moving objects up to 180 degrees, and prefers faces.

• Hearing -- begins prior to birth, and is mature at birth. The infant prefers frequencies of the human voice.

• Touch, taste, smell -- mature at birth; prefers sweet taste.

• Vestibular senses -- the infant responds to rocking and changes of position.

LANGUAGE DEVELOPMENT
Crying is a vitally important means of communication. By the 3rd day of life, mothers can distinguish their baby's cry from others. By the first month of life, most parents can tell if their baby's cry means hunger, pain, or anger. Crying also elicits a nursing mother's milk letdown. The inherent biological response in most humans to crying insures the infant's survival.

The amount of crying in the first 3 months varies in a healthy infant between 1 to 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 physiologic problem, and many experts believe it is associated with excessive gas in the bowel and or the inability to digest certain formulas. It may be associated also with overanxious mothers.

Excessive crying is can be associated with child abuse. Regardless of the cause, it is a complex problem that deserves a medical evaluation.

BEHAVIOR
The behavior of the newborn is characterized by 6 states of consciousness: quiet sleep, active sleep, drowsy waking, quiet alert, fussing, and active crying. The ability to move smoothly from one state to another is one of the most reliable signs of neurologic maturity and integrity. Heart rate, breathing, muscle tone, and body movements vary with each state.

Many physiologic functions are not stable in the first months after birth. This variability is normal and differs from infant to infant. Temperature control, skin color, stooling, yawning, gagging, hiccupping, and vomiting are easily affected by stress and stimulation.

Periodic breathing, in which breathing starts and stops again, is normal and is not a sign of SIDS (sudden infant death syndrome). Some infants will vomit after each feeding but have no organic pathology and continue to gain weight and develop normally.

Other infants grunt and groan distressfully while stooling but produce soft, blood-free stools and growth and feeding remain good. This is due to immature abdominal muscles for pushing and does not require any intervention.

Sleep/wake cycles are extremely variable and do not stabilize until 3 months old. These cycles occur in random intervals of 30 to 50 minutes after birth and gradually increase as the infant matures. By 4 months old, most infants will have one 5-hour period of uninterrupted sleep.

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 frequently.

Giving the child water is not necessary! Adequate hydration is indicated by 6 to 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
Safety is very important for infants. It is very important to consider their developmental stage. For example, around 2-3 months of age, the infant begins to roll over. Therefore, extreme caution must be taken while the baby is on the change table. Consider the following important safety tips:

• Place infant in a proper car seat in every car ride, no matter how short the distance. A car seat that faces backwards should be used until the infant is at least a year of age or longer if possible, then a forward facing car seat can be used safely. The safest place for the infant's car seat is in the back right passenger seat. It is vitally 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 prior to trying to help the infant.
• Do not leave an infant alone with siblings or pets. Even older siblings are seldom prepared to handle the potential emergency situations that may arise. 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 unattended on a surface from which the child can wiggle or roll over and fall off.
• Use gates on stairways and to block off rooms that are not "child proof" --remember, infants may learn to crawl or scoot as early as 6 months.
• Do not drink or carry anything hot while holding the infant, to avoid burning the infant -- remember, infants begin waving arms and grabbing for objects at 3 to 5 months.
• Do not allow older infants to crawl or walk around in the kitchen while adults or older siblings are cooking. The kitchen can be blocked off with a gate or the infant placed in a playpen, highchair, or crib while others cook.
• Never leave small objects within an infant's reach -- remember, infants explore their environment by placing everything they can get their hands on into the mouth.
• 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.
• Be aware of potential poisons (household cleaners, cosmetics, medications, even some plants) within your home and keep them stored up, out of the infant's reach and use drawer and cupboard safety latches. Know the number (and keep it posted near the phone) of your local Poison Control Center. Have a bottle of syrup of ipecac available in your home in case accidental poisoning occurs, but remember to call poison control first and use ipecac only if directed to do so by the poison control representative.

CALL HEALTH CARE PROVIDER IF:

• the infant does not look good; looks different from normal state -- the infant is not consolable by holding, rocking, or cuddling.
• the infant's growth or development does not appear to fall within normal.
• your infant seems to be "losing" developmental milestones. For example, if your 9 month old was able to pull to stand, but at 12 months is no longer able to even sit unsupported.
• you are concerned at any time.