1. Chapter 4: Prenatal Development
4.1 The Developing Baby
4.2 Problems in Prenatal Development
4.3 Avoiding Dangers to the Baby

2. Chapter 4 Objectives List the methods of family planning
Outline what occurs during each of the three stages of prenatal development
Contrast miscarriage and stillbirth
Identify how ten major birth defects can be diagnosed
Summarize the hazards that alcohol and other drugs pose to prenatal development
Assess why environmental hazards must be avoided during pregnancy
Describe how a fetus can be affected by certain illnesses the mother may contract

3. The Developing Baby
Chapter 4 Section 1

4. Family Planning
Many families carefully consider whether to have children and when to have them. However, anytime a couple has sexual intercourse, a pregnancy can occur. The only sure way to prevent pregnancy is abstinence, or avoiding sexual activity. Do you think this statement is true or false?
There are other methods of contraception which can help prevent pregnancy and it is important to understand which methods are out there. Most do not prevent STIs but they can prevent pregnancy.
Abstinence however is still the only way to prevent pregnancy and STIs
Not all forms of contraception are 100% affective. If one says 80% affective, that means that there is a 1 in 5 chance that a pregnancy could occur using that method.

5. Conception
About every 28 days, an ovum (egg) is released by one of a woman’s two ovaries.
This is called ovulation; at the same time certain hormones are released
During ovulation, the inner lining of the uterus grows and thickens.
If the ovum is not fertilized, the lining breaks down and passes out of the body
The menstrual period
When an ovum is released it travels through the fallopian tube (connects the ovary to the uterus)
This journey takes about 2-3 days

6. Conception
When the ovum reaches the uterus unfertilized, it typically breaks up
When a sperm, the male cell, reaches the fallopian tube it may penetrate and fertilize the ovum
The process when the sperm fertilizes the egg is called conception
Ovum's usually live hours while sperm are capable of fertilizing an ovum for about 48 to 72 hours
During a woman’s cycle, there are only about 3-4 days in which conception can occur

7. Conception

8. The Role of Genetics
People inherit many physical traits from their parents
Skin color
Hair color and texture
Eye color
Size and shape of ears
Much more…
Some children are more likely to have talents like musical talents or athletic ability

9. The Role of Genetics
At the moment of conception, every human baby receives 46 chromosomes
A chromosome is a tiny threadlike structure in the nucleus of every cell
Chromosomes come in 23 pairs
The fathers sperm and mothers ovum contribute 1 to each pair
Has hundreds to thousands of gene
A gene is a unit that determines a human’s inherited characteristics
The complete blueprint for the creation of a person is called a genome
The complex molecules that make up genes are called DNA
No two people, except identical twisn, have identical dna

10. Dominant and Recessive Genes
A dominant gene is a stronger gene
A recessive gene is a weaker one and will not be expressed
The terms dominant and recessive only refer to the relationship of genes to each other
What factor determines the characteristic that a person will express is the dominant gene
EX: Red hair genes often skip a generation because the gene is recessive
Most traits are influenced by multiple genes
Height, weight, personality, and intelligence

11. Let’s Practice

12. Making a Unique Person
Heredity explains why people in some families look so much alike and why some do not
EX: one child with brown hair and another with bright blond hair
The gender of the child is determined at conception
Sex chromosomes come in two types X and Y
Woman carries the X, and the man carries the X or Y
So if a man fertilizes an X chromosome with a Y chromosome the combination is for a boy. XX is for a girl.

13. 1st Month At 2 weeks: size of a pin head
Egg attaches to the lining of the uterus
Critical stage for brain and spinal cord development
Internal organs and circulatory system begin to form
The heart begins to beat

14. 2nd Month Size about ¼” long at the beginning of the month
Face, eyes, ears, and limbs take shapes
Bones begin to form

15. 3rd Month Size about 1” as the month begins
Nostrils, mouth, lips, and eyelids form
Buds for all 20 baby teeth appear
Fingers and toes almost complete
All organs present but still immature

16. 4th Month About 3” long; weighs 1 ounce as the month begins
Can suck its thumb, swallow, hiccup, and move around
Facial features become clearer

17. 5th Month About 6 ½’-7” long and weighs 4-5 oz as month begins
Hair, eyelashes, and eyebrows appear
Teeth continue to develop
Organs are maturing
Becomes more active

18. 6th Month
Size about 8-10” long and weighs 8-12 oz. as the month begins
Fat deposits under skin, but fetus appears wrinkled
Breathing movements begin

19. 7th Month Size about 10-12” long and weighs 1 ½-2 lbs as month begins
Has periods of activity followed by periods of rest and quiet

20. 8th Month Size about 14-16” long, 2 ½-3 lbs as the month begins
May react to loud noises with a reflex jerking action
Moves into a head-down position

21. 9th Month
Size about 17-18” long and weighs about 5-6 lbs as month begins
Weight gain continues
Skin becomes smooth as fat deposits continue to form
Movements decrease as the fetus has less room to move around
Acquires disease-fighting antibodies from the mother’s blood
Descends into pelvis, ready for birth

22. Chapter 4 Section 2
Problems in Prenatal Development

23. Losing a Baby Sometimes a baby does not develop normally
Sometimes the developing baby dies
Miscarriage is when a baby dies prior to the 20th week of pregnancy
Still birth is when a baby dies after the 20th week of pregnancy
About 15% of recognized pregnancies end in miscarriage
Causes are still not medically known
Still birth occurs in about 2% of pregnancies
Most common causes are problems with the placenta, abnormal chromosomes, poor growth, and infections

24. Dealing with Grief
Most couples feel a long sense of attachment prior to a baby’s birth
May go through similar stages of grief that a parent would to a child that was already born
Parents may blame themselves and feel alone
Couples may need support to deal with grief
Most couples that experience a miscarriage or stillbirth still have healthy children later

25. Birth Defects
A serious problem that threatens a baby’s health, and is present at birth, is called a birth defect
Some are mild that no one would ever know the child has a birth defect
Others can result in disabilities or even death
Approximately 120,000 babies are born each year in the US with a birth defect
Scientists are still trying to identify some causes
If found, could possibly decrease the occurrence of birth defects

26. Types and Causes of Birth Defects
Some defects cause an abnormality in the structure of the body
EX: extra or missing fingers/toes
Some defects cause one or more systems in the body to not function properly
EX: blindness, deafness, and mental retardation
Some abnormalities are not discovered until months or years after birth
4 main causes of birth defects currently:
Environment
Hereditary
Errors in chromosomes
Combination of environment and hereditary factors

27. Types and Causes of Birth Defects
Environmental
Hereditary
Nutritional balance of the mothers diet
Any diseases or infection the mother has
Harmful substances; alcohol, over-the-counter medication, illegal drugs, etc.
Some medicines help the mother but hurt the baby
Air pollution
Exposure to X-Rays and high levels of radiation
Parents can pass off faulty recessive genes
This is called recessive inheritance
Tay-Sachs disease
Cystic Fibrosis
Tay-Sachs disease affects the nervous system and causes it to malfunction
Cystic Fibrosis when thick mucus builds up in the lungs, digestive track and other areas of the body

28. Types and Causes of Birth Defects
Errors in Chromosomes
Interactions of Heredity and Environment
When a baby has too many or too few chromosomes
Most common birth defect is Down syndrome
1 in 800 children are born with a form of Down syndrome
When you have too many or too few it can affect the body’s systems
Heart defects
Leukemia
Poor muscle tone
Physical growth or motor development
When an environmental and hereditary factors are present
Examples
Cleft lip
Cleft palate
Heredity and medications
Spina bifida
A predisposition, tendency, are combined medications during pregnancy

29. Prevention and Diagnosis
Changing of your lifestyle
Frequent doctors visits for prenatal check-ups
Genetic counseling
Assesses their risk of having a child with a birth defect that is caused by a defect in genes
Compiling a family history
Prenatal Tests
More than 100 kinds of birth defects can be detected before birth

30. Prenatal Tests Alpha-fetoprotein (AFP) Ultrasound
Blood test between 15 and 20 weeks
AFP is produced in the liver of the fetus and shows up in the mothers blood
Abnormal levels can indicate a possible birth defect
Is a test that uses sound waves to make a video image of an unborn baby
Can monitor problems with a baby’s skeletal, circulatory, or nervous system
Usually during their 20th week
Many doctors now do 3D ultrasounds

31. Prenatal Tests Chorionic Villi Sampling Amniocentesis
The process of withdrawing a sample of the amniotic fluid surrounding the unborn baby
Often used as a test for Down syndrome with the mother is older than 35 years or older
Also may be completed if uncertain results are obtained from the AFP
Done between the 15th and 20th week
Uses a sample of tissue from the membrane that encases the fetus to check for birth defects
Tissue is cut off and analyzed
Newer techniques using a laparoscope are used to take samples and even operate on unborn babies. These procedures currently carry a risk however new technology makes these procedures safe for widespread use in the future.

32. Chapter 4 Section 3
Avoiding Dangers to the Baby

33. Effects of Alcohol and Other Drugs on Pregnancy
Essential parts of good prenatal care is avoiding hazards such as
Alcohol
Drugs
Smoking
X-Rays
Hazardous chemicals
Other harmful substances
Infections
Environmental Factors
Environmental factors include prescription and over-the counter drugs, caffeine, nicotine, illegal drugs, and inhalants

34. Fetal Alcohol Syndrome
Incurable condition found in some children of mothers that consumed alcohol during pregnancy
1 in 5 babies born with FAS do not live to 1 year old
Those that survive can have problems
Delayed physical growth
Heart, liver, kidney defects
Hyperactivity
Facial deformity
Mental retardation
Learning Disabilities
Even small amounts can harm the baby
Doctors do not know the exact amount that can harm a baby
Avoid any amounts when trying to become pregnant
Deformity is a defect in a structure

35. Alcohol Fetal Alcohol Effects
Abnormalities caused by the mother consuming alcohol during pregnancy
Suffer less than children with FAS
Extent of damage is directly related to the amount the mother drinks
Binge drinking increases your risk of having a child with FAS
Deformity is a defect in a structure

36. Prescription Drugs and Over-The-Counter Drugs
Extreme example of unsafe mediation is thalidomide
1950s- to relieve morning sickness
After proved harmful, 5,000 babies were born with birth defects
Missing or deformed arms, legs
Some acne medicine has been proven to cause problems
Chemicals found in some medications can cause mental retardation in the first 3 months
4-9 months, OTC drugs can cause slow growth, infections, and bleeding at birth

37. Caffeine Passes easily through the placenta
Cause high blood levels of caffeine for fetus
Increases fetal heart rate and movement
Consumed in large amounts:
Miscarriage
Premature birth
Low birth weight
Can draw fluid and calcium out of the body
Small amounts (2 cups of coffee or soft drinks per day) not a huge risk

38. Tobacco Cause: Low birth weight Premature birth Linked to:
Respiratory infections
Allergies

39. Illegal Drugs
Cocaine causes miscarriage, still birth, and premature births
Causes unborn child to have strokes resulting in brain and heart damage or even death
Low birth weight
Smaller heads
Risk of seizures
Risk of SIDS (sudden infant death syndrome)
Tremors
Exaggerated startle response
Irritability and developmental delays
Feeding and sleeping problems
Mothers pass their addiction to their baby
After birth, babies must go through a painful period of withdrawal
Long-term effects can be learning and behavioral disabilities

40. Illegal Drugs
Marijuana and methamphetamine use is liked to low birth weight and premature delivery
Breathing problems
Poor attention span
Drowsiness
Heart defects

41. Environmental Hazards
Two possible hazards to unborn babies include X-rays and hazardous chemicals.
Radiation from X-rays, or from other sources, can cause birth defects
If an X-ray is necessary during pregnancy, inform your medical staff because precautions can be taken
Dental X-rays are generally considered safe

42. Environmental Hazards
Hazardous Substances and Chemicals
Paint
Pesticides
Lead in water or paint
Carbon monoxide
Mercury found in some fish
Solvents, paint thinners, and formaldehyde

43. Diseases and Infections
Rubella
Toxoplasmosis
Rubella is also called the German measles
Mother contracts it
Birth defects can happen within 1st three months
Blindness
Deafness
Heart disease
Mental retardation
Caused by a parasite
Most people have immune systems to fight it off
Developing babies cannot
Causes:
Blindness
Hearing loss
Learning disabilities
Severe cases
Death
Long-term learning disabilities
Precautions:
Never clean a cats litter box

44. Diseases and Infections
Chicken Pox
Sexually Transmitted Infections
Viral infection
Depending when infection occurs during pregnancy will affect the outcome to the baby
1st half of pregnancy
Congenital Varicella Syndrome
Causes scarring of the skin, limb defects, eye problems
Some cases miscarriage
Passed from mother to baby
For Example:
Syphilis can be treated if caught early to the unborn baby
Can cause skin rash or lesions, bone/facial deformities, deafness, brain damage
2% end in miscarriage, stillbirth, or death
AIDS 35-65% it will be passed to the baby. Most babies are delivered by C-Section if the mother is known to have an STI
Herpes can cause the child to be born with brain infections or mental retardation. Some can die from the infection.