Download 5.1 - 5.4 (Prenatal Development)

Prenatal Development
Chapter 5
The Developing Child
Priscilla Evans
DHS
TEKS: 1.A; 1.C; 1.D; 2.B
Outline
 5-1:
The Developing Baby
 5-2: A Closer Look at Conception
 5-3: Problems in Prenatal
Development
 5-4: Avoiding Dangers to the Baby
Section 5-1 Objectives
 Distinguish
among the three stages
of pregnancy.
 Describe the prenatal
development during each stage
of pregnancy.
 Explain why changes affect a
woman during each stage of
pregnancy.
The Developing Baby

Prenatal Development
 a single cell grows and
develops into a human being
capable of life
 Takes about 9 months
Conception
 Ovum
– a female cell or egg
 Released once a month by one
of a woman’s ovaries
 The egg moves through the
Fallopian tube to the uterus, where
the baby develops during
pregnancy.
 Journey takes about 2-3 days.
Conception
 The
egg meets, and is
fertilized by a sperm, male
cell.
 Conception – when the ovum
and sperm unite
and pregnancy begins!!
Conception Diagram
Conception
 Fertilization
can take place only 23 days after the ovum has been
released.
 Sperm can live up to 7 days.
 There’s a period of about 10 days
each month during which a
female can become pregnant.
Baby’s Development
Three Stages:
 Zygote
Embryo
 Fetus
Period of the Zygote
 Zygote
– fertilized egg
 Last about 2 weeks
 Attaches itself to the lining of the
uterus and draws nourishment
from the mother.
 Grows by cell division
 The size of a pinhead
Period of the Embryo
Second stage
of pregnancy
 3rd – 8th weeks
of pregnancy
 Grows rapidly

5 – 6 weeks
Period of the Embryo
First Stage:
 Mass of cells develop into major
systems – heart, lungs, bones and
muscle.
 Internal organs unable to function.
 Brain begins to take control of
these body systems.
Period of the Embryo
Second Stage:
 A sac filled with fluid forms
around the embryo.
 Amniotic fluid – protects the
developing baby
 cushions it from falls or
bumps
Period of the Embryo
Third Stage:
 Placenta
 Tissue
 Rich in blood vessels
 Mother’s bloodstream
carries food and oxygen
here
Period of the Embryo
Fourth Stage:
 Umbilical cord
 Long tube that connects to
the placenta
 Carries food and oxygen
 Provides nourishment
 Takes away waste products
Period of the Fetus
8th/9th week – birth
 4th-5th month – kicks and other
movements touch the wall of
the uterus
 “Quickening” occurs
 As the fetus grows, so does the
amniotic fluid.

Period of the Fetus
The uterus expands, and the
abdomen grows.
 Just before delivery, the
amniotic fluid decreases.
 Baby is in the fetal position.

Period of the Fetus
By 7th month, fetus is capable
of living outside but not without
a medical help.
 The fetus gains weight rapidly.
 Stores nutrients and builds
immunity to diseases and
infections.

Period of the Fetus
It can do surprising things!
o Sucks its thumb
o Cough
o Sneeze
o Yawn
o Kick
o Hiccup
o Cry
Preparing for Birth
 9th
month
 “ Lightening” - the baby’s weight
seems to shift down and the
mother feels more comfortable in
her upper abdomen.
 the baby drops
 might not occur until just before
labor
Preparing for Birth
The fetus is upside down, the
head is nestled in the mother’s
pelvis.
 The baby is less active
 The mother’s skin and abdomen
muscles stretch.
 After 37-42 weeks of preparation,
the baby is ready to be born.

Section 5-2 Objectives
Describe how personal
characteristics are inherited.
 Explain the cause of multiple
births.
 Evaluate different possible
solutions for infertility.

The Genetic Package
Each person inherits
personal
characteristics from
his/her parents.
The Genetic Package
 At
conception, every
human baby receives
46 chromosomes, tiny
threadlike particles on
the nucleus of every
cell.
 These chromosomes
come in 23 pairs.
The Genetic Package
Each chromosome has
thousands of genes, the units
that determine the child’s
inherited characteristics.
 For ever inherited characteristic,
a person receives two copies of
one gene.
 When both are the same, the
child has that characteristic.

The Genetic Package
What happens if a person
receives two different genes?
 dominant – stronger gene
 recessive – weaker gene, it will
not be expressed
Making a Unique Person
Each sperm or egg cell contains a
different combination of genes.
 Personal traits are determined by
the particular combinations of
genes brought together at
conception.

Making a Unique Person:
Sex Chromosomes
X – egg cell/female
 X or Y – sperm/male
 XX = girl
 XY = boy
So who determines the sex
of a child?

Multiple Births

Identical
 began as one
zygote
always the same
sex
 have very similar
characteristics
Multiple Births
Fraternal
 two eggs are released at the
same time and each is fertilized.
 they grow side by side in the
uterus
 may be opposite sexes

Multiple Births
When more than two babies
are born, they may be identical
or fraternal – or a combination.
 It depends on whether one
fertilized egg splits or more than
one egg is fertilized at the same
time.

Multiple Births
In the U.S., about 2 ½ % of
births are twins.
 Fraternal twins occur 3 times
more often than identical
twins.
 Multiple births are happening
at a growing rate because
people are getting treatments.

Infertility
Infertility – inability to become
pregnant
 Couples may feel abnormal
and/or alone.
 Medical advances have helped
many of these couples.
 Surgery or medication may solve
the problem.

Infertility
Fertility drugs stimulates a
woman’s ovaries to release eggs.
 Drawbacks
 lung problems
 abdominal pain
 nausea
 dizziness
 multiple births

Options for Infertile Couples
Adoption
 couple legally takes all
responsibilities for raising a child
already born
• Artificial insemination
 a doctor injects sperm into a
woman’s uterus with a special
needle

Options for Infertile Couples

In vitro fertilization
 a woman has damaged
Fallopian tubes
 in a small glass, a doctor
combines a mature egg from the
woman and sperm from her
husband
 the doctor places the zygote in
the woman’s uterus
Options for Infertile Couples

Ovum transfer
 this procedure uses an egg
taken from female donor
and in vitro fertilization
 it may used by women who
lack ovaries or who has
inherited disorders
Options for Infertile Couples

Surrogate mother
 substitute
 mother is a woman who
becomes pregnant for another
couple
 she may carry a couple’s
fertilized egg, removed from the
mother
Options for Infertile Couples
•Surrogate cont.
artificially
inseminated w/
sperm from the husband
 include legal arrangements
and must meet state laws
Questions Raised
Technology advances offer
options
 Not everyone thinks these
alternatives are acceptable.
 The use of ovum
transfers/surrogate mothers is
controversial.
 Raises ethical questions.

Section 5-3
Contrast miscarriage and stillbirth.
 Identify some major birth defects.
 Explain the 4 causes of birth
defects.
 Describe how birth defects can be
diagnosed and prevented.

Losing a Baby
 Miscarriage
baby dies before 20 weeks of
pregnancy
 Stillbirth
 baby dies after 20 weeks of
pregnancy

Losing a Baby
As many as 20% of all
pregnancies end in a miscarriage.
 These loses can be severe shocks
and bring pain.
 Parents go through the same grief
as does anyone who has had a
family member die.
 Most couples are able to have a
successful pregnancy later.

Types of Birth Defects
Birth Defects – babies born with
serious problems that threaten their
health or ability to live.
 About 3 out of every 100 children
born in the U.S. have a birth defect.
 Some can be mild or can be
corrected.
 Others result in severe lifelong
disabilities or even death.

Types of Birth Defects
Some birth defects affect the
shape or size of the body or of
certain parts of the body.
 Not all birth defects are
apparent.

Causes of Birth Defects
Scientist don’t yet understand
the cause of about 60% of all
birth defects.
 They have found four main
causes for birth defects.

Causes of Birth Defects:
Environmental
 Many choices the mother makes
can affect the development of
the baby:
 The nutritional balance of her
diet
 Diseases/infections the mother
has during pregnancy.
 Harmful substances the mother
takes in, including alcohol,
tobacco, and drugs.
Causes of Birth Defects:
Environmental
Some medicines that benefit
the mother, but which can hurt
the baby.
 Exposure to outside hazards
such as radiation, especially
early pregnancy.

Causes of Birth Defects:
Environmental
A
father’s exposure to alcohol, drugs,
and other substances can also affect
the baby.
 Sperm take three months to develop.
 Alcohol , drugs, and tobacco affect
the way the sperm forms; they
produce changes in the
chromosomes.
Causes of Birth Defects:
Environmental
 Cocaine
has been found to
adhere to the sperm and
affect the baby from the
moment of conception.
 What responsibilities does a
future father have?
Causes of Birth Defects:
Heredity
1,000’s of genes make up a
genetic blueprint.
 For each person about 5 or 6
of the recessive genes are
imperfect.
 A single copy of these genes
will have no effect on the
development of the child.

Causes of Birth Defects:
Heredity
 Sometimes each parent passes
on the same recessive
defective gene.
 Sometimes a defective gene
is dominant.
 In these cases, the baby may
develop a birth defect.
Causes of Birth Defects:
Heredity
 Some inherited conditions
affect only one sex.
 Hemophilia – a condition that
prevents the blood from
clotting
 Color blindness
Only affects MALES
Causes of Birth Defects:
Errors in Chromosomes
A
few types of birth defects are
linked to a problem with the
baby’s chromosomes.
 There may be too many – or too
few – chromosomes in each of the
baby’s cells.
 This is not a hereditary defect.
Causes of Birth Defects:
Errors in Chromosomes
 Down
Syndrome
1in every 800 births
Risks increase if the
mother is 35 or older
Child has an extra
chromosome 21
www.kidshealth.org/parent/medical/genetic/down_syndrome.html - 29k -
Causes of Birth Defects:
Interaction of Heredity &
Environment
 Researchers think that the
interactions of heredity and
environment is probably the
cause for cleft lip, cleft plate,
and spina bifida.
Prevention & Diagnosis of
Birth Defects
 Genetic
Counseling
 It does not tell people what to do;
it only explains the options and
risks
 Family doctors can perform
genetic counseling, but it is best
provided by a specialist.
 Genetic counselors are trained to
understand genetic disorders.
Prevention & Diagnosis of Birth
Defects: Genetic Counseling
 Genetic
counselors obtain a
complete record of the family’s
medical history.
 Patient/family members may be
given physical examinations.
 When test/questionnaires are
completed, the counselor can
usually tell the couple whether
genetic problems are present.
Prenatal Test
 More
than 100 kinds of birth
defects can now be
diagnosed.
 Some test can alert the
physician to a condition in the
baby that must be treated
before or immediately after
birth.
Prenatal Test
 Today
doctors use three
procedures to make prenatal
diagnosis:
 Ultrasound
 Amniocentesis
 Chorionic villi sampling
Prenatal Test: Ultrasound
 Uses
sound waves to make as
video image of an unborn baby to
check for specific health
problems.
 It show if the fetus is developing on
schedule.
 Can confirm the due date or that
twins are present.
Prenatal Test:
Amniocentesis
 Is
the process of withdrawing a
sample of the amniotic fluid
surrounding an unborn baby
and testing that fluid for
indications of specific birth
defects or other health
problems.
Prenatal Test:
Amniocentesis
 Most
often used as a test for
Down Syndrome when a
mother is over the age of 35.
 About 1:200 women who have
had amniocentesis have a
miscarriage.
Prenatal Test: Chorionic Villi
Sampling
 Tests for specific birth defects by
sampling small amounts of tissue
from the membrane that encases
the fetus.
 A doctor inserts a small tube
through the vagina into the
uterus.
 Sample of tissues are snipped or
suctioned off for analysis.
Prenatal Test: Chorionic Villi
Sampling
 Is
used to test for the same
disorders as amniocentesis.
 The advantage is that it can
be done earlier in a
pregnancy.
 Risks are much greater
Section 5-4 Objectives:
 Identify
the hazards that
alcohol and other drugs
pose to prenatal
development.
 Discuss other environmental
hazards that pregnant
women should avoid.
Alcohol:
 Fetal
Alcohol Syndrome (FAS)
Includes physical and mental
problems that results from a
mother drinking alcohol while
she is pregnant.
Other Drugs…
 Medicines,
including both those
that doctors prescribe and overthe-counter types.
 Caffeine, found in some foods and
beverages.
 Nicotine, found in tobacco.
 Illegal drugs (i.e. LSD, heroin,
ecstasy)
 Inhalants
Fetal Alcohol Syndrome
 1:5
babies born with FAS dies
soon after birth
 Symptoms
Mentally retarded
Slow growth
Poor coordination
Heart defects
Symptoms…
 The
Visible
Teen
Fetal Alcohol Effects
 Less
severe than FAS
 Degree of damage to the child
is usually directly related to the
amount of alcohol the mother
consumed during pregnancy.
 There is not cure for FAS or FAE,
only prevention – DON’T
DRINK!!
DID You Know ?
 Antibiotics
Prescribed
to fight
infections
Can discolor a baby’s
permanent teeth
Affect its growth
Disturb its liver function
Prescription & Over-TheCounter
 Aspirin,
cold remedies and
antihistamines can harm an
unborn child.
 1st Trimester – most critical
Drugs can cause mental
retardation
Prescription & Over-TheCounter
rd
3
Trimester
Cause slow growth,
infections, or bleeding at
birth
Will still be in baby’s system
at birth
Prescription & Over-TheCounter
Even common medicines that are
sold in pharmacies and
supermarkets may be unsafe for
an unborn baby.
How can a pregnant woman be
sure that a medicine is safe?
By checking with her doctor
Caffeine
 Widely
found in beverages such as
coffee, tea, and cocoa.
 Caffeine is often not considered a
drug – but it is!!
 Large quantities have been
associated with a variety of problems:
 Increased risk of miscarriage
 Low birth weight
 Higher risks of infant deaths
Tobacco
 Baby
likely to be smaller
than the average child
 Premature birth
 Linked to respiratory
infections and allergies
among children after birth
DID You
 Smoking
Know
?
During Pregnancy
Baby’s birth weight is reduced
by about ¼ lb. for every pack
of cigarettes that a pregnant
woman smokes each day.
Passive smoking has similar
effects
Illegal Drugs
 A mother
who is addicted to a drug when
pregnant usually passes her addiction on
to her baby.
 Addicted babies go through a period of
withdrawal, as a result may die.
 Children may experience long term effects
(i.e. unable to follow simple instructions,
unable to comprehend in classes)
X-Rays
 Radiation
may cause birth
defects
 Avoid unneeded X-rays
before pregnancy.
 Both men and women
should request a abdominal
shield during routine x-rays.
Sexually Transmitted
Diseases (STDs)
Syphilis
Gonorrhea
Hepatitis B
AIDS
Genital herpes
Chlamydia
 Can result in serious illness,
deformity, or even death.
Sexually Transmitted
Diseases (STDs)
 Most doctors routinely check
pregnant women for syphilis –
mandatory in most states.
 Treatment can cure syphilis and
gonorrhea and can relieve the
symptoms of herpes in adults.
 No drug can cure the damage of
the newborn that results from a
Developing Healthy Habits for a
Lifetime
 Physical
Health
Have regular check-ups
Eat balanced diet
Get regular exercise
Get plenty of sleep
Learn safety rules
Avoid harmful substances
Healthy Habits
 Emotional
Health
List your accomplishments
Use positive “self-talk”
Handle your emotions
 Social Health
Spend time with your family
Be a good friend
Play an active part in your
community
Following Up…
 What
are effective ways of
handling negative emotions?
 How can adopting these habits
help make a person ready to
be a parent?
 How can learning good time
management skills now
prepare you for the future?
Help This Unborn Child
*
answers will vary
 #1
– Dyanne should stop
smoking while she’s pregnant.
Smoking causes problems like
low birth weight. She should
not drink alcohol during the
pregnancy because that can
lead to birth defects.
Help This Unborn Child
#2
– Should not take the
vitamins, nose drops, or
aspirin w/o getting her
doctor’s approval. Any of
those substances might
be harmful to the baby.
Help This Unborn Child
 #3
– Researches agree that there
is no known safe level of caffeine,
so Elaine should stop drinking
coffee during her pregnancy. The
chocolate in the brownies have
caffeine as well. She’d be better
off finding a different treat. Since
she is pregnant, she should not
have had x-rays at the dentist’s
office.
Help This Unborn Child
#4
– The amphetamines
could easily harm the
baby. She should not skip
meals either.