A newborn is a baby under the age of three months, as defined by WhatToExpect.com, website of the wildly popular "What to Expect When Expecting" series of books. Through the first three months of life, you're likely to see a variety of changes in your newborn that tell you how he is progressing and growing. Watching the various physical development stages of a newborn week-by-week can alert you to problems and allow you to understand the changes that are taking place in your baby.
One to Three Weeks
At one to three weeks, your newborn is still getting used to her new surroundings. Her eyesight is not yet focused, and anything more than 12 to 18 inches away will appear blurry, notes the Disney family website Wondertime.go.com. Your baby may be able to suck on her thumb to comfort herself, but likely cannot hold her head up. While she may be able to move her head around, her neck must be carefully supported when you hold her.
Three to Five Weeks
During the next few weeks, your newborn will start exploring arm movement. While the arm movements will likely be jerky, it is an important way he learns to gain control over his body. The American Academy of Pediatrics (AAP) notes that in this block of time, your newborn will start recognizing sounds and smells, knowing when you're near. If breastfeeding, he'll likely remember he wants to eat when he smells breast milk. Foster bonding time through holding your baby close.
Five to Seven Weeks
You'll begin to notice more drastic changes in the next few weeks. With the administration of daily "tummy time" in small spurts, your baby will soon learn to hold her head up and strengthen her previously weak neck muscles. You may even notice her first real smiles, says Babycenter.com. She'll start using facial expressions to communicate to you how she is feeling: a content look for happiness and a scowl for discomfort. Her eyes can see more clearly now and may be able to track an object across the room.
Eight to Ten Weeks
Your two-and-a-half-month-old baby should have greater control over his head, lifting it while on his tummy. The AAP also notes that this is the time where he'll likely become interested in simple toys and rattles that he can grasp and shake. His dominion over his physical actions grows as he opens and closes his hands, kicks his legs and manipulates objects. He loves to look at faces and may prefer to watch you over that baby DVD you bought. He'll likely begin to talk and babble as if he's having a real conversation.
Ten to Twelve Weeks
When your newborn turns three months old she is finally considered an infant. She may not even resemble the baby that you delivered at the hospital. Chubby cheeks, smiles and bright eyes accompany her new range of talents, like clapping, blowing raspberries and even giggling. You start to see glimmers of her personality. While your three-month-old isn't yet crawling, she might pull her knees under her belly during tummy time in preparation. She'll learn to roll from back to front, indicating her anticipation of becoming mobile sometime soon.
