Prenatal Development

1. Prenatal Period
Chapter II- Child and Adolescent Period

2. Topics to be discussed:
• Characteristics of the period
• Prenatal Development
o How life begins
o Ovulation, fertilization, conception
o Genetic and chromosomal abnormalities
o Multiple births
o In vitro fertilization
• Stages/Periods of Prenatal Development
• Environmental effects on prenatal development
(Teratogens)
Chapter II- Child and Adolescent Period

3. Characteristics of the period
“A person’s a person, no matter how small.”
-Dr. Seuss
Chapter II- Child and Adolescent Period

4. • This is the first developmental period in the life span.
• The shortest and the most important period.
• refer to period of development before birth.
• period that ranges from conception to birth.
• period approximately lasts for about 280 days.
Chapter II- Child and Adolescent Period

5. 6 important characteristics
of prenatal period
1) The heredity endowment
2) Favourable conditions
3) Sex
4) Proportionally greater growth and development
5) The prenatal period is a time of many hazards, both
physical and psychological.
6) The prenatal period is the time when significant
people form attitudes towards newly created
individuals.
Chapter II- Child and Adolescent Period

6. FACTORS THAT
INFLUENCES THE
PRENATAL DEVELOPMENT
1) Age of the mother
2) Illness and infections
3) Blood RH factor
4) Birth complications
5) Drugs
6) Environmental hazards
Chapter II- Child and Adolescent Period

7. The origin of life
Chapter II- Child and Adolescent Period

8. How life begins?
Chapter II- Child and Adolescent Period

9. What do many scientists
claim?
Chapter II- Child and Adolescent Period
Evolution

10. What does the evidence
reveal?
• Researchers have learned that for a cell to survive,
at least three different types of complex molecules
must work together—DNA (deoxyribonucleic acid),
RNA (ribonucleic acid), and proteins.
Chapter II- Child and Adolescent Period

11. What does the Bible say?
• The Bible states that life on earth is the product of
an intelligent mind. Note the Bible’s clear logic: “Of
course, every house is constructed by someone, but
he that constructed all things is God.” (Hebrews 3:4)
Chapter II- Child and Adolescent Period

12. What does the evidence
reveal?
• Your body is one of the most complex structures in
the universe. It is made up of some 100 trillion tiny
cells—bone cells, blood cells, brain cells, to name a
few. 7 Infact,therearemorethan200different types of
cells in your body.
Chapter II- Child and Adolescent Period

13. Ovulation
• Approximately every month an egg will mature
within one of the ovaries.
• when a mature egg is released from the ovary,
pushed down the fallopian tube, and is available to
be fertilized.
Chapter II- Child and Adolescent Period

14. Ovulation Calendar
Chapter II- Child and Adolescent Period

15. 2 parts of ovulation cycle
• follicular phase. first half of the cycle, this phase
starts the first day of the last menstrual period (LMP)
and continues until ovulation.
• luteal phase. The second half of the cycle from the
day of ovulation until the next period begins.
Chapter II- Child and Adolescent Period

16. **ovulation can help a woman get a better idea of
when pregnancy can and cannot occur during her
monthly cycle.
Chapter II- Child and Adolescent Period

17. Fertilization
Chapter II- Child and Adolescent Period

18. • Occurs when the sperm successfully enters the
ovum membrane.
• Sperm should be ejaculated during sexual
intercourse (or during artificial insemination)
Chapter II- Child and Adolescent Period

19. Conception
• Occurs when a female egg (ovum)is penetrated
and fertilized by the male sperm.
• The union of the mother’s and father’s sex cells, also
known as gametes or germ cells.
o Mother’s sex cell are eggs
o Father’s sex cells are sperm
• Successful conception depends on:
o ovaries releasing one healthy egg cell.
o Egg cell migrates most of the way down the fallopian tube.
o One sperm must penetrate the ovum to form a zygote.
Chapter II- Child and Adolescent Period

20. Genetic and chromosomal
abnormalities
An overview:
• Chromosomes are structures within cells that
contain a person's genes
• A gene is a segment of DNA and contains the code
for a specific protein that functions in one or more
types of cells in the body
• Every normal human cell, except for sperm and egg
cells, has 23 pairs of chromosomes for a total of 46
chromosomes.
Chapter II- Child and Adolescent Period

21. • Sperm and egg cells have only one of each pair of
chromosomes for a total of 23.
• Each chromosome contains hundreds to thousands
of genes.
• The sex chromosomes are one of the 23 pairs of
chromosomes.
• Normal people have 2 sex chromosomes, and each
is either an X or a Y chromosome.
• Normal females have two X chromosomes (XX), and
normal males have one X and one Y chromosome
(XY).
Chapter II- Child and Adolescent Period

22. Chromosomal
Abnormalities
• Chromosomal abnormalities can affect any
chromosome, including the sex chromosomes.
• Chromosomal abnormalities affect the number or
structure of chromosomes and may be visible with a
microscope in a test called karyotype analysis.
Chapter II- Child and Adolescent Period

23. Types of Chromosomal
Abnormalities
• Numerical abnormalities occur when a person has
one or more extra copies of a chromosome (one
extra is trisomy, and two extra is tetrasomy) or is
missing a chromosome (monosomy).
• Structural abnormalities occur when part of a
chromosome is abnormal.
a. Deletions
b. Duplications
c. Translocations
d. Inversions
e. Rings
Chapter II- Child and Adolescent Period

24. Genetic abnormalities
• Small changes (mutations) may occur in a specific
gene.
• Some substances or agents in the environment are
capable of damaging and causing mutations in
genes, and these mutations may be passed from
parent to child. These substances are called
mutagens.
Chapter II- Child and Adolescent Period

25. Testing for chromosomal
and genetic abnormalities
• A person's chromosomes and genes can be evaluated
by analyzing a sample of blood.
.
Chapter II- Child and Adolescent Period
amniocentesis –is a diagnostic procedure in
which a needle is inserted into the womb of a
pregnant woman and a small amount of
amniotic fluid is removed.
chorionic villus sampling-procedure that
analyzes samples of placental tissue to
assess fetal wellbeing.

26. Prevention
• Although chromosomal abnormalities cannot be
corrected, some birth defects can sometimes be
prevented.
Chapter II- Child and Adolescent Period

27. When Part of a
Chromosome Is Missing
• A number of syndromes can occur in infants who
are missing parts of chromosomes.
• These syndromes are called chromosome deletion
syndromes .
o cri du chat syndrome (cat’s cry syndrome),
o Prader-Willi syndrome
o Wolf-Hirschhorn syndrome
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28. Multiple births
Chapter II- Child and Adolescent Period

29. Facts
• The scientific study of twins is known as
“gemellology”. The word is probably derived from
an ancient German word twine which means ‘two
together’
• Worldwide there are at least 125 million living
multiples.
• Did you know that up to 22 percent of twins are left-
handed. In the non-twin population the number is
just under 10 percent.
Chapter II- Child and Adolescent Period

30. • Twins and multiples have been known to develop
their own language (known as cryptophasia or
idioglossia) that only they understand.
• The average time between the delivery of the first
and second twin is 17 minutes.
Chapter II- Child and Adolescent Period

31. Genetics and Types of
Twins/Triplets
• Maternal Family history of twins.
• Fraternal (dizygotic/trizygotic) twins/triplets
• Identical (monozygotic) twins/triplets
• Mirror image twins
• Conjoined twins (Siamese)
• Polar Body or Half identical twins
• Twins of two
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32. In vitro fertilization (IVF)
Chapter II- Child and Adolescent Period

33. What is IVF?
• is a process by which an egg is fertilized by sperm
outside the body.
• is a major treatment for infertility when other
methods of assisted reproductive technology have
failed
• The process involves monitoring a woman's
ovulatory process, removing ovum or ova (egg or
eggs) from the woman's ovaries and letting sperm
fertilize them in a fluid medium in a laboratory.
• When a woman's natural cycle is monitored to
collect a naturally selected ovum (egg) for
fertilization, it is known as natural cycle IVF.
Chapter II- Child and Adolescent Period

34. Why IVF?
• used to overcome female infertility in the woman
due to problems of the fallopian tube, making
fertilization in vivo difficult.
• It may also assist in male infertility, where there is a
defect in sperm quality, and in such cases intra
cytoplasmic sperm injection (ICSI) may be used,
where a sperm cell is injected directly into the egg
cell.
Chapter II- Child and Adolescent Period

35. • This is used when sperm have difficulty penetrating
the egg, and in these cases the partner's or a
donor's sperm may be used. ICSI is also used when
sperm numbers are very low.
Chapter II- Child and Adolescent Period

36. METHOD
i. Ovarian hyper stimulation
ii. Natural and mild IVF
iii. Final maturation and egg retrieval
iv. Egg and sperm preparation
v. Fertilization
vi. Embryo culture
vii. Embryo selection
viii. Embryo transfer
Chapter II- Child and Adolescent Period

37. RISKS IN IVF
• There may be a failure to recover an egg because:
- follicles that contain mature eggs may not
develop in the treatment cycle
- ovulation has occurred before time of egg
recovery
- one or more eggs cannot be recovered
- pre-existing pelvic scarring and/or technical
difficulties prevent safe egg recovery.
• The eggs that are recovered may not be normal;
Chapter II- Child and Adolescent Period

38. Stages/Period of Prenatal
Development
Chapter II- Child and Adolescent Period

39. Stages of Prenatal
development
• Zygotic (or Germinal) Stage 0-2 weeks
• Embryonic Stage 2-8 weeks
• Fetal Stage 9-40 weeks
Chapter II- Child and Adolescent Period

40. Zygotic/Germinal Period
• Begins when egg is fertilized in the fallopian tube
• Period of rapid cell division
• Ends 2 weeks later when the zygote is implanted in
the wall of the uterus
Chapter II- Child and Adolescent Period

41. Developmental Process
• The zygote is transformed into an embryo and then
a fetus through the process of:
o Cell Division- begins 12 hours after fertilization and continues throughout
fetal development.
o Cell migration- cell move from point of origin to elsewhere in the embryo
o Cell differentiation- cells begin to specialize, fulfilling the needs of
separate bodily structures and functions.
o Cell death- the selective death of certain cells as they are no longer
needed
Chapter II- Child and Adolescent Period

42. Key terms
• Zygote- The genetic material of the sperm and egg
combine to form a single cell.
o Union of sperm and egg cell.
• Cleavage- process of rapid division of zygote.
• Blastomeres- first two identical cell.
• Morula- sixty hours after fertilization, approximately
sixteen cells have formed, still enclosed by the zona
pellucida
Chapter II- Child and Adolescent Period

43. • Blastocoele- a fluid-filled cavity that forms in the
center of the group of cells.
• Trophoblasts-outer shell of cell
• Embryoblasts- inner mass of cells.
• Blastocyst- previously morula, when zona pellucida
disappeares
**at this stage the blastocyst consists of 200-300 cells
and is ready for implantation.
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46. • Implantation- the process in which the blastocyst
implants to the uterine wall, occurs approximately
six days after conception.
• The blastocyst first adheres to the wall then moves
into the uterine tissue.
• Implantation marks the end of the germinal stage
and the beginning of the embryonic stage.
Chapter II- Child and Adolescent Period

47. Embryonic Stage
• From 2 to 8 weeks after conception
• Begins after implantation and last until eight weeks
after conception
• Cell differentiation intensifies
• Life support systems for the embryo develop
• Organs Appear
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49. Germ layers
• Ectoderm (outer layer)-develops skin, hair, nails,
sense organs, nervous tissue
• Mesoderm (middle layer)-develops muscles, bones,
circulatory system, lymph system, kidneys, gonads
• Endoderm (inner layer)-develops pharynx, tonsils,
thyroid, trachea, lungs, digestive system, bladder,
urethra
Chapter II- Child and Adolescent Period

50. Major events that occur
during this stage
• Week 3: Beginning development of the brain, heart,
blood cells, circulatory system, spinal cord, and
digestive system.
• Week 4: Beginning development of bones, facial
structures, and limbs (presence of arm and leg
buds); continuing development of the heart (which
begins to beat), brain, and nervous tissue.
Chapter II- Child and Adolescent Period

51. • Week 5: Beginning development of eyes, nose,
kidneys, lungs; continuing development of the heart
(formation of valves), brain, nervous tissue, and
digestive tract.
• Week 6: Beginning development of hands, feet,
and digits; continuing development of brain, heart,
and circulation system.
Chapter II- Child and Adolescent Period

52. • Week 7: Beginning development of hair follicles,
nipples, eyelids, and sex organs (testes or ovaries);
first formation of urine in the kidneys and first
evidence of brain waves.
• Week 8: Facial features more distinct, internal
organs well developed, the brain can signal for
muscles to move, heart development ends, external
sex organs begin to form.
Chapter II- Child and Adolescent Period

53. **by the end of the embryonic stage, all essential
external and internal structures have been formed.
**The embryo is now referred to as a fetus.
Chapter II- Child and Adolescent Period

54. Fetal stage
• From 9 weeks after conception to birth.
• The most dramatic stage
• Increase in size and systems begin to function
• Age of viability :22-28 weeks
• Although all of the organ system were formed
during the embryonic development, they continue
to develop and grow during the fetal stage
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56. The Fetal Support System
• Placenta: permits he
exchange of the materials
between the bloodstreams of
mother and fetus.
• Umbilical Cord: structure
containing blood vessels
connecting fetus and mother.
• Amniotic sac: membrane
within which the fetus floats in
a clear liquid that acts as a
protective buffer.
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71. Environmental Effects on
Prenatal Development
Chapter II- Child and Adolescent Period

72. • Teratogens – refers to any disease or viruses, or other
environmental agent that can harm a
developing embryo or fetus by causing physical
deformities, severely retarded growth,
blindness, brain damage and even death.
Chapter II- Child and Adolescent Period

73. Examples of Teratogens
1. Maternal Diseases Rubella (German measles) – is a
disease that has little effects on mother but may
cause a number of serious birth defects in unborn
children who are exposed in the first three trimester
to four months of pregnancy.
2. Toxoplasmosis – is a disease caused by a parasite
found in a raw meat and cat feces; can cause birth
defects if transmitted to an embryo in the first
trimester. It can cause severe eye and brain
damage to the developing embryo if transmitted.
Chapter II- Child and Adolescent Period

74.  Drugs also taken by pregnant women could
harm developing organisms.
 Examples:
1. Thalidomide – is a mild tranquilizer that
produce a variety of malfunctions of the
limbs, eyes, ears and heart of the baby.
2. Diethylstilbestrol (DES) – is a synthetic
hormone that can produce cancer in
adolescent female offspring and genital
tract abnormalities in males.
Chapter II- Child and Adolescent Period

75. Sexually transmitted disease or STD can produce
serious birth defects. Three (3) of this diseases are:
1. Syphilis – is a common sexually transmitted disease
that may cross the placental barrier in the middle and
later stages of pregnancy causing serious eye, ear,
bone, heart or brain damage.
2. Genital herpes – is a sexually transmitted disease
that can infect infant at birth, causing blindness, brain
damage or even death.
3. Acquired Immune Deficiency Syndrome (AIDS) – is
a viral disease that can be transmitted from a mother
to her fetus that result in a weakening of the body’s
immune system and, and ultimately death.
Chapter II- Child and Adolescent Period

76. • Fetal Alcohol Effects (FAE) – are group of mild congenital
problems sometimes observed in children of mothers
who drink sparing to moderately during pregnancy.
• Fetal Alcohol Syndrome (FAS) – are group of serious
congenital problems commonly observed in the children
of mothers who abuse alcohol during pregnancy.
Other factors are:
1. Poverty
2. Mother’s Age
3. Drug use
4. Alcohol
Chapter II- Child and Adolescent Period

77. 6. Smoking and Nicotine
7. Diseases
8. Mother’s diet and Physical health
9. Mother’s prenatal
10. Environmental toxins
11. Low birth weight
Chapter II- Child and Adolescent Period

78. Prenatal Diagnosis and
Treatment
• Diagnosis: ultrasound, amniocentesis, and chorionic
villus sampling can detect physical deformities and
genetic disorders
• Treatment: fetal medicine and genetic engineering
are experimental
Chapter II- Child and Adolescent Period

79. Prenatal Diagnosis
Chapter II- Child and Adolescent Period

80. Labor and Delivery
• Stage 1: starts when the muscles of the uterus
contract and ends when the cervix is fully enlarged
(about 10 cm)
• Stage 2: baby is pushed down the birth canal
• Stage 3: placenta is expelled
Chapter II- Child and Adolescent Period

81. Three Stages of Labor
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82. Chapter II- Child and Adolescent
Period
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