Download The Developing Baby

Pregnancy
Everything You Ever
Wanted to Know
The Developing Baby
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Conception
• Ovum released from an ovary
• Egg moves through the fallopian tube to the
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uterus
Egg reaches uterus and flushed out by
menstrual cycle, or fertilized by sperm
Ovum and sperm unite=conception
Zygote- 1st stage
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Zygote-fertilized egg, last about two
weeks
Travels through fallopian tube and
attaches to lining of uterus
• Provides nourishment to zygote
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Zygote grows by cell division
• 1,2, 4, etc
• After 2 weeks, only the size of a pin head
Embryo-2nd stage
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Embryo grows rapidly
Mass of cells develops into the major systems
of the body
Brain begins to take control of body systems
Amniotic fluid develops to protect embryo
Placenta develops, rich in blood vessels,
mom’s blood carries food and oxygen to
placenta
Reaches baby through umbilical cord-brings
nourishment to baby, takes away waste
Fetus-3rd stage
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Beings at 8-9th week
4th or 5th month-fetal movements touch wall of uterus
(quickening)
Uterus grows and expands, more fluid produced
By 7th month, fetus is capable of living outside the womb
Major organ systems ready to operate
Fat deposits added under skin
Fetus stores nutrients and build immunity
Can suck thumb, cough, sneeze, kick, hiccup, and cry
before birth
Preparing for Birth
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Lightening-baby dropped in birth canal
Fetus usually upside down-easiest and
safest position for birth
Mother’s skin on abdomen appears
stretched to capacity, muscles are
stretched
37-42 weeks, baby is ready to be born
Vocabulary
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Chromosomes-threadlike particles in the
nucleus of every cell
Genes-units that determine a person’s
inherited characteristics
Dominant-stronger gene
Recessive-weaker gene
Infertility-inability to become pregnant
The Genetic Package
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Inherit characteristics from parents
At conception every human receives 23
pairs of chromosomes
Chromosomes have thousands of genes
For each inherited characteristic, child
receives 2 copies of each gene
• If the same, get that characteristic
• If different, dominant gene is expressed
Recessive Traits
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Blue, green, or hazel eyes
Straight hair
Blonde or red hair
Second toe longer than big toe
Continued
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Combination of genes make up genetic
package and sex
Sex chromosomes are X and Y
• Egg contains X
• Sperm contain X or Y
• XX girl
• XY boy
Activity
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Make a chart of your family from
grandparents through parents, aunts and
uncles to present generation
Show eye color and shape, hair color
and texture, shape and size of ears,
hand, feet, any other physical
characteristics that are passed down
through generations and describe the
pattern
Issues in Prenatal
Development
Multiple Births
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Identical twins-egg splits in 2
Fraternal twins-2 eggs both fertilized
2.5% of births are twins
Infertility
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Seek medical advice and give a
complete health history
Surgery or medication can help solve
problem
Ovaries are not producing eggs,
prescribe fertility drugs
• Side effects: lung problems, abdominal pain,
nausea, diarrhea, dizziness, multiple babies
Options for Infertile Couples
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Adoption
Artificial insemination-doctor injects
sperm into woman’s uterus
In vitro fertilization-in small glass dish,
woman’s egg and male’s sperm
combined, then zygote placed in
woman’s uterus
http://video.nationalgeographic.com/vide
o/player/science/health-human-body-
Continued
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Ovum transfer-egg from female donor
and in vitro fertilization
Surrogate mother-become pregnant for
another couple
• Can carry couple’s fertilized egg
• Artificially inseminated (legal arrangements
and meet state laws)
Problems in Prenatal
Development
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Miscarriage-happens before 20 weeks of
pregnancy, baby dies
Stillbirth-happens after 20 weeks of
pregnancy
• Go through stages of grief
• 20% of pregnancies end in miscarriage
• Most women can have successful
pregnancies later
Types of birth defects
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Serious problems that threaten a child’s
health or ability to live
Some are mild or easily corrected,
others are severe
Every 3 out of 100 children born in US
have a birth defect
Not all are apparent at birth
Causes of Birth Defects
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4 main causes
Environmental causes
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All major organ systems develop in first few weeks or
pregnancy, choices mom makes and mom’s health
affect developing systems
Nutrition
Diseases or infections of mother
Alcohol, tobacco, drugs
Medications
Exposure to outside hazards such as radiation
Hereditary Causes
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For each person about 5 or 6 recessive genes
are imperfect
If each parent passes on the same recessive
defective gene, baby may develop birth defect
Dominant gene can be defective too
Some inherited conditions only affect males
such as hemophilia and color blindness
Errors in Chromosomes
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Could be too many or too few
chromosomes
• Not inherited from parents
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Most common is Down syndrome
• 1 in every 800 births
• Risk increases in women over 35
• Child has extra chromosome, interferes with
development
Interaction of Heredity and
Environment
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Examples like cleft lip, cleft palate, and
spina bifida
Inherit the tendency, combined with
environment factor during pregnancy
Cleft Lip
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Cleft Lip
Cleft Palate
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Cleft Palate
Spina Bifida
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Spina Bifida
Prevention and Diagnosis
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Infections, drugs, and alcohol exposure
can be controlled
Genetic counseling-counselors trained to
understand genetic disorders
• Obtain complete family medical history
• Diseases and cause of death of close relatives
• Thorough medical exams
• States likelihood of genetic problems
Prenatal Tests
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More than 100 birth defects can be
determined before a baby is born
3 procedures used:
• Ultrasound-uses sound waves to make a
video image of unborn baby to check for
specific health problems and rates of
development
• Detects defects to skeleton and other organs
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Amniocentesis-method of removing a
sample of amniotic fluid surrounding the
unborn baby, test fluid for specific birth
defects
• Some cells of the fetus contained in the fluid
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and tested
Test for Down syndrome if mother over 35
1 in 200 women miscarry after test
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Chorionic villi sampling-sample small
amounts of tissue
• Test for same defects that amniocentesis
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does, but can be done earlier
Higher risks than amniocentesis
Avoiding Dangers to the Baby
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Alcohol- Fetal Alcohol Syndrome
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Physical and mental problems
1 out of 5 with FAS die soon after birth
Almost all are mentally retarded
Slow growth, poor coordination, heart defects, facial
deformaties
Fetal alcohol effects-less severe
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Degree of damage is directly related to amount of
alcohol mom consumed during pregnancy and at what
stage
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FAS
Other Drugs
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Prescription and OTC
Caffeine
Nicotine
Illegal drugs
Inhalants-fumes that are inhaled into the
lungs
Medications
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Thalidomide- used to relieve morning sickness
in late 1950’s
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5,000 babies born with severe birth defects
Medicines or infections that reach baby in first
3 months are the most devastating
Last 6 months of pregnancy, may cause slow
growth, infections
Drugs taken just before delivery will be in
baby’s body at birth
Caffeine
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Found in coffee, tea, soft drinks, cocoa,
some foods, medications
Large doses can cause birth defects
Tobacco
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Low birth weight
Prematurity
Respiratory infections and allergies after
birth
Illegal Drugs
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Pass addiction to child
Go through withdrawal right after birth, painful
condition
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Cocaine is known to cause miscarriage,
stillbirth, premature birth, birth defects
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Can be so severe that they die
Similar results with marijuana
Babies who survive withdrawal have an
uncertain future
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Drug addiction
Other Dangers
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X-rays- radiation can cause birth defects
Rubella-vaccine now available
STD’s-can be passed on from pregnant
woman to unborn baby
• Routinely check for syphilis and treat
newborns eyes with a solution to kill
gonorrhea germs that could cause blindness
AIDS
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Developing baby can be infected by
mother
If mother with AIDS gives birth to a baby,
baby is at risk of developing AIDS
Mom can be given treatment that
reduces chances of baby developing
AIDS
Early testing very important