Download zygote

Prenatal and Neonatal
Prenatal Development
• Prenatal development lasts
approximately 38 weeks from
conception to birth.
• Three periods of development:
▫ Zygote
▫ Embryo
▫ Fetus
Zygote Period
• The zygote is formed at conception
and continues to develop for the
first two weeks.
• The zygote travels from the
fallopian tube to the uterus and
implants itself in the uterine wall.
• After 2 weeks, the placenta begins
to grow and is attaches to the
zygote via the umbilical cord.
Embryo Period
• The embryo period begins at the end
of the second week and ends at the
end of the eighth week.
• First half of this period:
▫ The ectoderm, mesoderm, and
endoderm layers develop.
▫ The heart begins to pump.
• Second half of this period:
▫ Facial features, arms, legs, fingers, and
toes form.
▫ Can respond to touch.
Fetus Period
• The fetus period begins in the
ninth week and continues through
birth.
• At the beginning of this period:
▫ Organs, muscles, and the nervous
system organize.
▫ The lungs expand and contract.
▫ The external genitals are
distinguishable.
▫ The fingernails, toenails, tooth
buds, and eyelids develop.
Fetus Period (continued)
• 18 Weeks - Fetal movements are
felt by the mother.
• 20 Weeks - The fetus can hear
sounds and react to them.
• 24 Weeks - All the brain neurons
are developed.
• 25 to 38 Weeks – The fetus has a
chance for survival outside the
womb. This is called the age of
viability.
Prenatal Health Issues
• Teratogens - environmental
substances that cause damage
during prenatal development
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Medications
Drugs, cigarettes, and alcohol
Radiation and pollution
Infectious disease
• Other health issues can include:
▫ The mother’s nutrition and stress
level
▫ Rh blood incompatibility
▫ The mother’s age and previous
pregnancy experiences
Medications
• Almost all medications that are
taken by the mother can reach the
embryo or fetus through the
bloodstream.
• Medications can cause:
▫ Low birth weight
▫ Lower intelligence later in life
▫ Death
• Mothers must consult doctors
before taking any medications.
Illegal Drugs
• Fetuses exposed to illegal drugs in
the womb are at risk of:
▫ Low birth weight
▫ Numerous defects
▫ Death
• If the fetus manages to survive
through birth, the baby is likely
born with a drug addiction.
Cigarettes
• Cigarette smoking while pregnant
can cause:
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Low birth weight
Cancer in childhood
Miscarriage
Death
• Second-hand smoke can also put
children at risk
Alcohol
• Fetal alcohol syndrome (FAS) is a
serious effect caused by the
mother consuming alcohol during
pregnancy.
• Children with FAS may have:
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Mental retardation
Poor attention
Hyperactivity,
Facial abnormalities
Slow growth
Radiation
• Pregnant women should avoid
exposure to radiation, including
medical X-rays.
• Exposure to radiation can
cause:
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Miscarriage
Poor physical growth
Brain damage
Cancer
Pollution
• Some environmental pollution
dangers include mercury, lead,
and PCBs.
• Exposure to pollutants can
cause:
▫ Brain damage
▫ Mental retardation
▫ Low birth weight
Infectious Disease
• Infectious disease can be difficult
for pregnant mothers to evade.
• Common illnesses such as the cold
and flu are essentially harmless to
the fetus as long as the mother is
well-rested and continues to get
nutrients.
• Serious infectious disease can
cause:
▫ Birth defects
▫ Low birth weight
▫ Miscarriages
Non-Teratogen Prenatal Health Issues
• Pregnant women must be
certain to get proper nutrition.
The level of malnutrition of the
mother is directly linked to brain
weight in the child.
• Pregnant women should also try
to remain stress-free. Anxiety
can have harmful effects on the
fetus.
Non-Teratogen Prenatal Health Issues (continued)
• Rh blood incompatibility
between the mother and fetus
can cause:
▫ Mental retardation
▫ Heart damage
▫ Death
• Blood tests and vaccines are
given to prevent illness or injury
resulting from Rh
incompatibility.
Neonatal Development
• The first four weeks of life are called
the neonatal, or newborn, stage.
• In this stage, special attention is
given to:
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Parent-child bonding
Reflexes
Temperament
States of arousal
Sensory capabilities
The Apgar Scale
• The Apgar scale rates newborns in
the following areas:
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Appearance
Pulse
Grimace
Activity
Respiration
• Apgar scores:
▫ 7 to 10 – Healthiest
▫ 4 and 6 – Need assistance with
breathing or other vital signs
▫ 0 and 3 – Need serious emergency
medical attention
Bonding
• Bonding is a parent’s deep
affection and concern for the
newborn.
• Parents and children develop a
special bond that allows the
infant to grow and develop with
confidence.
• Some parents instantly bond,
while other parents bond over
the first few weeks.
Reflexes
• Reflexes are expected,
automatic responses to specific
stimulants.
• Newborn reflexes include:
▫ Rooting reflex
▫ Sucking reflex
▫ Palmer reflex
• Most of these reflexes should
disappear as the baby grows
and develops.
Sensory Capabilities
• Touch – most important sense
for newborns
• Taste – prefer sweet over salty
• Smell – respond to good and
bad smells
• Sound – special interest in the
human voice
• Vision – least developed sense
in a newborn
Newborn States of Arousal
• Newborns continually cycle
through five states of arousal:
▫ Regular sleep – deep sleep with
little movement
▫ Irregular sleep – light sleep with
body movement
▫ Drowsiness – waking up or falling
asleep
▫ Quiet alertness – awake and
attentive
▫ Waking activity and crying –
uncoordinated movements and
irregular breathing
Neonatal Health Issues
• The transition from the womb
into the world does not occur
smoothly.
• Neonatal health issues include:
▫ Premature birth
▫ Respiratory issues
▫ Sudden Infant Death Syndrome
Premature Birth
• Premature birth is used to describe
infants that are preterm or smallfor-date.
▫ Preterm babies are born 3 weeks or
more before the 38-week due date.
▫ Small-for-date babies weigh less
than expected compared to their
length of time in the womb.
• With proper care and special
attention, many premature babies
go on to lead normal, healthy lives.
Respiratory Issues
• In respiratory distress syndrome, a
baby’s air sacs collapse, which
makes breathing very strenuous
• Respiratory distress syndrome can
occur in premature or full-term
babies.
• Babies with respiratory distress
syndrome are attached to
respirators until they can breathe
comfortably on their own.
SIDS
• Sudden Infant Death Syndrome
(SIDS) occurs when an infant dies
during sleep.
• Death occurs with no trauma to the
child and no indication from the
child, such as crying, prior to death.
• No cause, cure, or prevention has
been found for SIDS.