Ch 4 –
Pregnancy
Child Growth and
Development
Where the Baby is Formed
Conception
 Every
28 days, an ovum is released by one
of the woman’s two ovaries.
 Uterus
is pear shaped, able to expand
during pregnancy.
Conception
 During
ovulation, inner lining of the uterus
grows and thickens. If the egg is not
fertilized, the lining breaks and passes
though.
 Ovum
travels through the fallopian tube
to the uterus.

Takes about 2-3 days.
Conception
 When
the ovum reaches the uterus,
usually it breaks up and leaves the body.
 When
the sperm reaches the fallopian
tube it may penetrate and fertilize the
ovum.

This process is known as conception.
Conception
 Ovum
can live 12-24 hours
 Sperm
can live 48-72 hours
 Ectopic
pregnancy is when the baby
starts to grow in the fallopian tubes
instead of the uterus.

Dangerous for the mother and does not
end with a live birth.
Role of Genetics
 Inherit
physical traits, talents, and abilities
from parents.
 At
conception babies get 46
chromosomes.
 Each chromosome has hundreds of
genes.
 Only
identical twins have the same DNA
Dominant and Recessive
Genes
 Dominant
gene is the “stronger” one.
 Recessive gene is the “weaker” one.
 Only expressed when it is received from
both parents.

XX girl XY boy.
Multiple Pregnancy
 When
two or more babies develop in the
same pregnancy


Twins are the most common
Occur in 3% of pregnancies
Multiple Pregnancy
 http://pregnancy.healthguru.com/video/
multiple-births-twins-triplets-and-more
Multiple Pregnancy
 Fraternal
children develop from two or
more ova and have a different genetic
makeup


most common
each baby has own chorion
 Identical
children develop from same ova
and sperm and have the same genetic
makeup
 Mixed types of pregnancy must include
fraternal and identical babies
4.1 Vocab









Ovum
Uterus
Fallopian tube
Sperm
Conception
Chromosome
Gene
Genome
DNA
Infertility
Surrogate
Prenatal Development
Zygote
Embryo
Amniotic fluid
Placenta
Umbilical cord
fetus
Prenatal Development
 Prenatal
development takes place between
conception and birth
 There are 3 stages in prenatal development



germinal stage
embryonic stage
fetal stage
Germinal Stage (Zygote)
 The
first stage of development
 From conception to 2 weeks


Zygote forms
Implantation of egg occurs (at 10 days)
Zygote
Embryonic Stage (Embryo)
 Embryonic
stage is the second stage of
development, lasts about six weeks






most crucial to development
baby is called an embryo
development of most body systems
heart begins to beat
cartilage is present before bones form
substances pass from mother’s placenta
through the umbilical cord
Embryo
Fetal Stage (Fetus)
 Fetal
stage is the third stage of
pregnancy, lasts from about nine weeks
after conception until birth






bone starts to replace cartilage
baby is known as a fetus
all parts of the body mature
overall size increases quickly
hear heartbeat in the third month
quickening (when the fetus moves) begins
between the fourth and fifth months
Fetus
Reverse Conception Calendar
 http://www.babymed.com/conception-
calculator
Fetal Stage Cont.
 Age
of viability is the age at which a
baby could survive if born, 28 weeks


still need extensive medical care
better chance of survival each week the
baby is not born
 During


last two months of pregnancy,
inner layer of lungs produces substance
that allows for breathing air
receives immunities from mother in the ninth
month
Month-by-Month Posters
 Nine
groups – 1 group for each month of
pregnancy
 Must include:




an overall description of what occurs
during that month
At least five facts
At least 3 pictures
Must be neat and professional. Take your
time and make it look good! You will be
presenting these.
Problems in Prenatal
Development
Losing a Baby
•
When baby passes away prior to the 20th
week of pregnancy it is called a
miscarriage.
–
•
After the 20th week it is called a stillbirth.
–
•
15% of pregnancies
2% of pregnancies
Grief is similar to the loss of an already
born child.
Birth Defects
 There
 Can
 Birth
are hundreds of birth defect types.
be physical or mental
defect can result in body structure
abnormalities or cause a body part to
malfunction, as with blindness, deafness,
or mental retardation.
Birth Defects
 Can be
caused by
 environmental factors
 hereditary
 errors in chromosomes
 combination of environmental and
hereditary factors
 Think:
What environmental factors do you
know?
Birth Defects
 Do’s
and Don’ts or Pregnancy Poster
 Environmental
Hazards Wordle
Birth Defects
 Cerebral Palsy – varying problems in the motor system

Caused by damage to the brain before, during, or shortly after
birth
Birth Defects
 Cleft Lip and
Cleft Lip Palate – gap in the upper lip or palate
that causes problems with eating, swallowing, speech, and
appearance.

Caused by hereditary, environmental factors, or both.
Birth Defects
 Cystic fibrosis – affects respiratory and digestive systems.
Many die before adulthood, although treatment now allows
sufferers to live longer.

Caused by inheriting defective recessive genes from both parents.
Birth Defects
 Down Syndrome – a group of problems that may include
mental retardation; heart, blood, and digestive system
difficulties; and poor muscle tone.

Caused by presence of an extra chromosome 21.
Birth Defects
 Muscular Dystrophy – Involve
shrinking of muscles.

Caused by mostly heredity.
progressive weakness and
Birth Defects
 PKU – condition in which the body is unable
to process and
use a specific protein present in nearly all foods. Brain damage
and mental retardation can result.

Caused by defective recessive genes inherited from both parents.
Birth Defects
 Sickle Cell Anemia – malformed red blood
cells interfere with
the supply of oxygen to all parts of the body. Symptoms
include tiredness, lack of appetite, and pain. Can lead to early
death.

Caused by defective recessive genes inherited from both parents.
Birth Defects
 Spina Bifida and Hydrocephalus – An incompletely formed
spinal cord may lead to stiff joints, partial paralysis, and
problems with the kidneys and urinary tract. 70% of children
with spina bifida also have hydrocephalus, in which excess of
fluid surrounds the brain

Caused by combination of heredity and environmental factors.
Birth Defects
 Tay-Sachs Disease
– Body is unable to process and use certain
fats because of lack of a specific chemical in the baby’s blood.
Leads to severe brain damage and death, usually by the age of
4.

Caused by defective recessive genes inherited from both parents.
Avoiding Dangers to the Baby
A fetus needs to be protected from many
dangers.
 These include the mother drinking alcohol
or taking other drugs, environmental
hazards, diseases, and infections.

Health Hazards to Avoid During
Pregnancy
 Diseases or illnesses in the mother
 Drugs

recreational and prescription
 Radiation exposure

medical X-rays should be avoided
 Environmental pollution

lead, chemicals, pesticides, herbicides
Diseases and Infections
 An infection in a pregnant woman can pose a risk for
the
unborn baby.
 Some infections include:
 Rubella- can cause blindness, deafness, heart disease,
and mental retardation
 Toxoplasmosis- can cause blindness, hearing loss, and
learning disabilities or cause a miscarriage or still birth
 Chicken Pox- fetus can contract congenital varicella
syndrome (scarring of skin, eye problems, limb defects)
 STIs – can be past on to the infant (like AIDS)
 Syphilis – skin rash, bone or facial deformities, deafness,
brain damage
 Genital Herpes- can cause brain infection or mental
retardation
Drugs to Avoid during Pregnancy
 Medications




Prescribed – in 1950 thalidomide was prescribe to relieve
morning sickness. The medication caused more than 5,000
babies to be norm with birth defects such as missing limbs
over-the-counter – antacid can harm the fetus
dietary supplements – large amounts of caffeine can harm the
fetus
herbal products
 Alcohol

fetal alcohol syndrome (FAS)
 Nicotine – can cause low birth weight, smaller babies,
premature birth, and is linked to respiratory infections and
allergies
Drugs to Avoid During
Pregnancy

Illegal drugs – drug addicted babies; cocaine
increase the risk of miscarriage, still birth,
premature birth, stroke in fetus, low birth weight,
and higher risk of SIDS

SIDS (Sudden Infant Death Syndrome)


The sudden, unexpected death of a baby under
the age of one with no clear cause.
Marijuana and methamphetamine use are also
linked to low birth weight and premature delivery.
Can cause breathing difficulties, poor attention
span, drowsiness, or heart defects in children.
Drugs to Avoid during Pregnancy
FAS
In what ways do the Fetal Alcohol Syndrome baby and Drug
Addicted baby act and look different from a normal baby?
After seeing the effects of FAS, what would you do if you
saw a pregnant woman drinking?
http://www.youtube.com/watch?v=X9ap3Iimimk
http://www.youtube.com/watch?v=31M_GDVYLe0&featur
e=related (3:03)
Environment Hazards
 X-Rays – can cause birth defects (dental x-rays are
considered safe)
 Paint  Pesticides
 Lead
 Carbon Monoxide
 Mercury
 Solvents, paint thinners, and formaldehyde