Typical 4-month-old infants are expected to develop certain physical and mental skills. These skills are called milestones.

All children develop a little differently. If you are concerned about your child's development, talk to your child's health care provider.

PHYSICAL AND MOTOR SKILLS

The typical 4-month-old baby should:

• Show a slowing of weight gain to approximately 20 grams per day
• Double the birth weight
• Have almost no head lag while in a sitting position
• Be able to sit up straight if propped
• Raise head 90 degrees when placed on stomach
• Be able to roll from front to back
• Try to reach objects with hands (may commonly overshoot)
• Hold and let go of an object
• Play with rattle when it's placed in the hands, but won't be able to pick it up if dropped
• Be able to grasp rattle with both hands
• Be able to place objects in mouth
• Sleep 9 to 10 hours at night with two naps (total of 14 - 16 hours per day)

SENSORY AND COGNITIVE SKILLS

A 4-month-old baby is expected to:

• Have well-established close vision
• Increase eye contact with parents and others
• Have beginning hand-eye coordination
• Be able to babble and coo
• Be able to laugh out loud
• Anticipate feeding when able to see a bottle (if bottle-fed)
• Begin to show memory
• Demand attention by fussing
• Recognize parent voice or touch

PLAY

You can encourage development through play:

• Place the baby in front of a mirror
• Provide bright-colored toys to hold
• Repeat sounds the infant makes
• Help the infant roll over
• Use a swing or stroller
• Play on the stomach (tummy time)

Feigelman S. The first year. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elevier; 2007: chap 8.