After an average pregnancy of 38 to 42 weeks, new parents encounter their newborn baby for the first time. There are many things about a newborn baby that make these littlest humans different from older infants. They are completely dependent on their parents for care, but at the same time are developed sufficiently to allow them to function outside the womb that has been protecting them for the past nine months.
Definition
A baby is considered newborn immediately after birth up until four to six weeks of age. This also includes premature infants, although these babies are sometimes considered newborn for a longer period of time, as their in-womb growth was not completed. As a baby exits the newborn period, he will lose the physical characteristics associated with birth, such as a misshapen head, puffy eyes and the attached umbilical cord stump. Newborns transitioning to infants will also become more aware of and interactive with the world around them as their senses develop further.
Size and Shape
Newborns typically weigh between 5 and 10 lbs. and range in length from 19 to 21 inches. The newborn baby has an identifiable shape, with a large head and small body and limbs. The head is often compressed into a slightly cone-like appearance from travel through the birth canal if the mother had a vaginal birth. Babies delivered by Cesarean section will not have this compression of the head.
First Experiences
The physical experience of birth is just one in a series of new first experiences for a newborn baby. The newborn, in the first few minutes of life, will take a first breath and cry for the first time. Shortly after birth, he will nurse for the first time and have a first bowel movement, which is made up of a substance called meconium, a sticky black substance made up of amniotic fluid and other components that were swallowed while still in the womb.
Umbilical Cord
A newborn baby will have a portion of the umbilical cord, called the umbilical cord stump, still attached to her belly button for 10 to 20 days. Parents of newborns often use special diapers with a cutout for the cord or fold down the diapers so the cord will not be pressed against the baby or get wet from the diaper. The cord will fall off by itself when it is ready.
Behavior
A newborn baby will spend a lot of time sleeping---up to 16 hours a day. His sleep patterns are not set yet, so he will often sleep in short blocks of time, from two to four hours, instead of all through a night. Newborns will also need to eat frequently, usually every three to four hours, according to KidsHealth.org. Breastfed newborns may need even more frequent feedings.
Bonding
A newborn baby has many hormonal changes as her body adjusts to life outside the womb. These internal changes prime the newborn for absorbing sights, sounds and tastes of the world and catering to these newborn needs helps parents bond with their new baby. The newborn's hormones cause her to be alert and quiet shortly after birth and also kick-start her nursing instinct. These hormones can also produce physical effects, including small acne-like bumps on the newborn's face and genital enlargement.
