LIFESPAN DEVELOPMENT

1
Children Chapter 4 Prenatal Development
2
The Germinal Period

• First two weeks after conception
• Creation of zygote
• Continued cell division
• Attachment of zygote to uterine wall
• Differentiation of cells has begun

3
The Embryonic Period

• Two to eight weeks after conception
• Rate of cell differentiation intensifies
• Support systems for cells form
• Organogenesis organ formation
• Embryo has three layers of cells

4
The Fetal Period

• Begins two months after conception lasts about
  seven months, until birth
• Largest prenatal size and weight gains
• Fingers, toes, skin, features, lungs, other
  structures, and reflexes all develop to prepare
  for birth

5

• The three trimesters are not same as the three
  prenatal periods
• At birth, average baby weighs 7.5 pounds and is
  about 20 inches long

6
First trimester begins
Third trimester begins
The three trimesters of prenatal development
Second trimester begins
7
Confirming the Pregnancy and Calculating the Due
Date

• Pregnancy test checks for human chorionic
  gonadotropin (HCG)
• Pregnancy calculated from first day of the
  womans last menstrual period
• Lasts about 280 days or 40 weeks
• Fetal life begins at ovum fertilization

8
Early Signs and Symptoms of Pregnancy
9
Three Trimesters and Preparation for Birth
10
Preparation for the Babys Birth

• Braxton Hicks contractions increase
• Cervix becomes softer and thinner
• Awkwardness
• Fatigue and desire for pregnancy to end
• Nesting urge and spurts of energy

11
Expectant Mothers Nutrition and Weight Gain

• Nutrition
• Need for protein, iron, vitamin D, calcium,
  phosphorus, magnesium increases 50 percent, water
  is essential
• Weight Gain
• 25 to 35 pounds associated with best reproductive
  outcomes

12

• Weight Gain
• Maternal obesity adversely impacts pregnancy
  outcomes carries risks
• Hypertension
• Diabetes
• Respiratory complications
• Infections

13
Exercise During Pregnancy

• Exercise for shorter time intervals
• Decrease intensity as pregnancy progresses
• Avoid prolonged overheating
• Avoid high-risk activities

• Warm up, stretch, cool down
• After exercise, lie on left side 10 minutes
• Wear supportive shoes and bra
• Reduce exercise significantly in the last four
  weeks

14
Culture and Prenatal Care

• Prenatal care in the United States and around the
  world
• U.S. does not provide uniform prenatal care
• In developing countries poverty is rampant,
  health and nutrition of mothers is poor, and
  percentage of low birthweight reaches 50

15
(No Transcript)
16
Some General Principles

• Teratogen
• Any agent that causes a birth defect
• Only about half of potential effects appear at
  birth
• Severity and type of defect affected by
• Dose
• Genetic susceptibility
• Time of exposure

17
Prescription and Nonprescription Drugs

• Damage discovered after a cluster of deformed
  babies is born
• Specific antibiotics
• Some antidepressants
• Certain hormones
• Diet pills
• Aspirin
• Caffeine

18
Terogens and Timing of Their Effects on Prenatal
Development
Zygote Embryonic period (wks)
Fetal Period (wks)
Central nervous system
Most serious damage from teratogens in first 28
weeks
Heart
Arms
Eyes
Legs
Ears
Teeth
Palate
Period of susceptibility to structural defects
External genitalia
Period of susceptibility to functional defects
19
Psychoactive Drugs

• Psychoactive drugs
• Act on nervous system
• Alter states of conscious
• Modify perceptions
• Change moods

20

• Alcohol
• Fetal alcohol syndrome (FAS)
• Nicotine
• Cocaine
• Marijuana
• Methamphetamine
• Heroin

21
Environmental Hazards

• Fathers exposure to lead and radiation
• Certain pesticides
• Petrochemicals
• Environmental pollutants and toxins
• Toxic waste
• Manufactured chemicals

22
Infectious Diseases

• Rubella
• Sexually transmitted infections
• Syphilis
• Genital herpes
• AIDS, HIV infection

23
Incompatible Blood Types

• Between mother and father
• Between mother and baby
• Blood group (A, B, O, AB)
• Rh factor (positive, negative)
• Vaccine within 3 days of birth

24
Other Parental Factors

• Maternal nutrition and low birthweight
• Obesity during pregnancy
• Maternal agetoo young, too old
• Paternal age and risks
• Emotional states and stress
• Maternal hormonal treatments