The newborn baby
The newborn baby
Dr. Ali D. Abbas
Instructor, Fundamentals of Nursing Department, College of Nursing, University of Baghdad
[email protected]
LEARNING OBJECTIVES
After mastering the contents of this lecture, the student should be able to:
1. Define the terminologies.
2. Describe the size and appearance of the newborn.
3. Explain the states of arousal.
4. List the medical and behavioral assessment of the newborn.
5. Explain the early physical development of the newborn.
TERMINOLOGIES
Apgar Scale
Sight
Birthweight
Smell
Cerebellum
Taste
Cerebrum
Touch
Neonatal
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The newborn baby
CONTENTS
1. Introduction
2
2. Size and appearance 2
3. States of arousal 3
4. Medical and behavioral assessment 3
5. Early physical development 5
Principle of development 5
Physical growth 6
Nutrition 7
Brain and reflex behavior 7
Early sensory capacities 9
6. References 11
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The newborn baby
Introduction
The first four weeks of life, the neonatal period, is a time of
transition from the uterus, where a fetus is supported entirely by
the mother, to an independent existence. What are the physical
characteristics of newborn babies, and how are they equipped for
this crucial transition?
Size and appearance
An average newborn, or neonate, is about 20 inches long and
weighs about 7.5 pounds. At birth, 95 % of full-term babies weigh
between 5.5 and 10 pounds and are between 18 and 22 inches long.
Boys tend to be slightly longer and heavier than girls, and a
firstborn child is likely to weigh less at birth than laterborns.
In their first few days, neonates lose as much as 10 % of their
body weight, primarily because of a loss of fluids. They begin to
gain weight again at about the 5 day and are generally back to birth
weight by the 10 to the 14 day.
New babies have distinctive features, including a large head
(one-fourth the body length) and a receding chin (which makes it
easier to nurse). At first, a neonate's head may be long and
misshapen because of the "molding" that eased its passage through
the mother's pelvis. This temporary molding was possible because
an infant's skull bones are not yet fused; they will not be
completely joined for 18 months. The places on the head where the
bones have not yet grown together the soft spots, or fontanels are
covered by a tough membrane.
Many newborns have a pinkish cast; their skin is so thin that it
barely covers the capillaries through which blood flows.
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The newborn baby
States of arousal
Babies have an internal "clock," which regulates their daily
cycles of eating, sleeping, and elimination, and perhaps even their
moods. These periodic cycles of wakefulness, sleep, and activity,
which govern an infant's state of arousal, or degree of alertness.
Newborn babies average about 16 hours of sleep a day.
Changes in state are coordinated by multiple areas of the
brain and are accompanied by changes in the functioning of
virtually all body systems: heart rate and blood flow, breathing,
temperature regulation, cerebral metabolism, and the workings of
the kidneys, glands, and digestive system.
Newborns have about six to eight sleep periods, which vary
between quiet and active sleep. Active sleep is probably the
equivalent of rapid eye movement (REM) sleep.
As infants grow, their sleep needs diminish. At about 3
months, babies grow more wakeful in the late afternoon and early
evening and start to sleep through the night. By 6 months, more
than half their sleep occurs at night. The amount of REM (rapideye-movement) sleep decreases steadily throughout life.
Medical and behavioral assessment
The first few minutes, days, and weeks after birth are crucial
for development. It is important to know as soon as possible
whether a baby has any problem that needs special care.
The Apgar Scale: One minute after delivery, and then again
five minutes after birth, most babies are assessed using the Apgar
scale (see table 1).
The newborn is rated 0, 1, or 2 on each measure, for a
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The newborn baby
maximum score of 10. A 5-minute score of 7 to 10 indicates that the
baby is in good to excellent condition. A score below 7 means the
baby needs help to establish breathing; a score below 4 means the
baby needs immediate lifesaving treatment. If resuscitation is
successful, bringing the baby's score to 4 or more at 10 minutes, no
long-term damage is likely to result.
In general, Apgar scores reliably predict survival during the
first month of life.
Table (1): Apgar Scale
Assessing Neurological Status: The Brazelton Neonatal
Behavioral Assessment Scale (NBAS) is used to assess neonates'
responsiveness to their physical and social environment, to identify
problems in neurological functioning, and to predict future
development. It assesses motor or ganization as shown by such
behaviors as activity level and the ability to bring a hand to the
mouth; reflexes; state changes, such as irritability, excitability, and
ability to quiet down after being upset; attention and interactive
capacities,
as shown by general alertness and response to visual
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The newborn baby
and auditory stimuli; and indications of central nervous system
instability, such as tremors and changes in skin color. The NBAS
takes about 30 minutes, and scores are based on a baby's best
performance.
Neonatal Screening for Medical Conditions: Children,
who inherit the enzyme disorder phenylketonuria, will become
mentally retarded unless they are fed a special diet beginning in
the first three to six weeks of life. Screening tests administered
soon after birth can often discover such correctable defects.
Early physical development
1. Principles of Development:
According to the cephalocaudal principle, growth occurs from
the top down. Because the brain grows so rapidly before birth, a
newborn baby's head is disproportionately large. The head
becomes proportionately smaller as the child grows in height and
the lower parts of the body develop (see Fig. 1).
Sensory and motor development proceed according to the
same principle: infants learn to use the upper parts of the body
before the lower parts.
Fig. (1) Changes in proportions
of
the
human
body
during
growth.
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The newborn baby
According to the proximodistal principle (inner to outer),
growth and motor development proceed from the center of the
body outward. In the womb, the head and trunk develop before the
arms and legs, then the hands and feet, and then the fingers and
toes. During infancy and early childhood, the limbs continue to
grow faster than the hands and feet. Similarly, children first
develop the ability to use their upper arms and upper legs (which
are closest to the center of the body), then the forearms and
forelegs, then hands and feet, and finally, fingers and toes.
2. Physical Growth:
Children grow faster during the first three years, especially
during the first few months, than ever again. At 5 months, the
average baby boy's birthweight has doubled to 16 pounds, and, by 1
year, has nearly tripled to 23 pounds. This rapid growth rate tapers
off during the second and third years (see Figure 4-4); a boy
typically gains about 5 pounds by his second birthday and 3.5
pounds by his third.
A boy's height typically increases by 10 inches during the first
year, by almost 5 inches during the second year, and by a little
more than 3 inches during the third year, to top 37 inches. Girls
follow a parallel pattern but are slightly smaller; at 3, the average
girl weighs a pound less and is half an inch shorter than the
average boy. As a baby grows, body shape and proportions change
too; a 3-year-old typically is slender compared with a chubby,
potbellied 1-year-old.
Teething usually begins around 3 or 4 months, when infants
begin grabbing almost everything in sight to put into their mouths;
but the first tooth may not actually arrive until sometime between
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The newborn baby
5 and 9 months of age, or even later. By the first birthday, babies
generally have six to eight teeth. By age 3, all twenty primary, or
deciduous, teeth are in place, and children can chew anything they
want to.
3. Nutrition:
Breast milk is almost always the best food for infants. Why is
breast-feeding best? Breast milk is more digestible and more
nutritious than formula and is less likely to produce allergic
reactions. Human milk is a complete source of nutrients for at least
the first six months; during this time breast-fed babies normally do
not need any other food. Neither they nor formula-fed infants need
additional water.
The health advantages of breast-feeding are striking during
the first two years and beyond. Among the illnesses prevented or
minimized by breast-feeding are diarrheas, respiratory infections
(such as pneumonia and bronchitis). Breast-feeding seems to have
benefits for visual acuity and neurological development, and also
may help prevent obesity, though findings on this point are
inconclusive. Most studies also show benefits for cognitive
development.
4. The Brain and Reflex Behavior:
What makes newborns respond to a nipple? What tells them
to start the sucking movements that allow them to control their
intake of fluids? These are functions of the central nervous
system—the brain and spinal cord (a bundle of nerves running
through the backbone)—and of a growing peripheral network of
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The newborn baby
nerves extending to every part of the body. Through this network,
sensory messages travel to the brain, and motor commands travel
back.
Building the Brain: The growth of the brain is fundamental
to future physical, cognitive, and emotional development.
The brain at birth weighs only about 25 % of its eventual adult
weight of 32 pounds. It reaches 70 % of that weight at 1 year and
nearly 90 % by age 3. By age 6, it is almost adult size; but growth
and functional development of specific parts of the brain continue
into adulthood.
Major Parts of the Brain: Beginning about two weeks after
conception, the brain gradually develops from a long hollow tube
into a spherical mass of cells (see Fig. 2). By birth, the growth spurt
of the spinal cord and brain stem (the part of the brain responsible
for such basic bodily functions as breathing, heart rate, body
temperature, and the sleep-wake cycle) has almost run its course.
The cerebellum (the part of the brain that maintains balance and
motor coordination) grows fastest during the first year of life.
The cerebrum, the largest part of the brain, is divided into
right and left halves, or hemispheres, each with specialized
functions. This specialization of the hemispheres is called
lateralization. The left hemisphere is mainly concerned with
language and logical thinking, the right hemisphere with visual and
spatial functions such as map reading and drawing. The two
hemispheres are joined by a tough band of tissue called the corpus
callosum, which allows them to share information and coordinate
commands. The corpus callosum grows dramatically during
childhood, reaching adult size by about age 10.
Each cerebral hemisphere has four lobes, or sections: the
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The newborn baby
occipital, parietal, temporal, and frontal lobes, which control
different functions and develop at different rates. The regions of
the cerebral cortex (the outer surface of the cerebrum) that govern
vision and hearing are mature by 6 months of age, but the areas of
the frontal lobe responsible for making mental associations,
remembering, and producing deliberate motor responses remain
immature for several years.
Fig.
(2)
Fetal
brain
development.
5. Early Sensory Capacities:
The developing brain enables newborn infants to make fairly
good sense of what they touch, see, smell, taste, and hear; and their
senses develop rapidly in the early months of life.
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The newborn baby
Touch and Pain: Touch is the first sense to develop, and for
the first several months it is the most mature sensory system.
When a newborn's cheek is stroked near the mouth, the baby
responds by trying to find a nipple. Early signs of this rooting
reflex occur two months after conception. By thirty-two weeks of
gestation, all body parts are sensitive to touch, and this sensitivity
increases during the first five days of life.
Smell and Taste: The senses of smell and taste also begin to
develop in the womb. The flavors and odors of foods an expectant
mother consumes may be transmitted to the fetus through the
amniotic fluid. After birth, a similar transmission occurs through
breast milk.
Hearing: Hearing, too, is functional before birth. Early
recognition of voices and language heard in the womb may lay the
foundation for the relationship between parents and child.
Auditory discrimination develops rapidly after birth. Threeday-old infants can tell new speech sounds from those they have
heard before. At 1 month, babies can distinguish sounds as close as
"ba" and "pa".
Because hearing is a key to language development, hearing
impairments should be identified and treated as early as possible.
Sight: Vision is the least developed sense at birth. The eyes of
newborns are smaller than those of adults, the retinal structures
are incomplete, and the optic nerve is underdeveloped. Newborns
blink at bright lights. Their peripheral vision is very narrow; it
more than doubles between 2 and 10 weeks of age. The ability to
follow a moving target also develops rapidly in the first months, as
does color perception.
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The newborn baby
References
Diane, P.; Sally, O., and Ruth, F.: Human Development, 9th ed., McGraw
Hill Company, United States, 2004, P.P. 113-137.
Papalia, D.; Olds, S., and Feldman, R.: Human Development, 9th ed.,
McGraw Hill Company, United States, 2008, P.P. 102-115.
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