1. Chapter 4 Prenatal Development and Birth

2. Chapter 4- Prenatal Development
Time of fastest development in life span
Environment extremely important
Conception
Ova travels from ovary to uterus
Penetration by 1 of sperm
Outcome: single-celled ZYGOTE

3. Prenatal Stages Germinal period: days 1-14
Implantation: 1/2 are successful
Miscarriage: 15% (recognized) to 50%
Embryonic period: 3rd to 8th week
Organogenesis, Sexual differentiation
Fetal period: 9th week – birth
Proliferation, migration
Differentiation of stem cells
Ends in tremendous brain development

4. Prenatal Environment
Reciprocal influence
Person and environment
Good and bad influences important
Teratogen: environmental agent
Harms the developing fetus
Critical Period: Organogenesis
Dosage & duration
Genetic make-up: susceptibility

5. Figure 4. 3 The critical periods of prenatal development
Figure 4.3 The critical periods of prenatal development. Teratogens are more likely to produce major structural abnormalities during the third through the eighth prenatal week. Note, however, that many organs and body parts remain sensitive to teratogenic agents throughout the nine-month prenatal period
Figure 4.3

6. Teratogens-Drugs
Thalidomide (for morning sickness)
All or parts of limbs missing
Tobacco: miscarriage, low birth weight, SIDS, slows fetal growth
Alcohol: FAS
Small, facial deformities, retardation
Cocaine: Processing difficulties

7. Figure 4.6 A. Characteristic features of a child with fetal alcohol syndrome. B. Child with fetal alcohol syndrome illustrating many of the features in the drawing. These children may also have cardiovascular and limb defects.
Figure 4.6

8. Teratogens - Diseases
Rubella (German Measles)
Blind, deaf, heart, brain
Syphilis:miscarriage, blind, deaf, heart, brain
After 18th week
AIDS mothers transmit to babies (15%-35%)
Prenatally, perinatally, postnatally

9. Teratogens – Environmental Hazards
Radiation: MR, leukemia, cancer, mutations, spontaneous abortions, etc.
Avoid X-rays when pregnant
Pollutants
In air and water
Lead - MR (also postnatally)

12. The Mother’s State
Age: typically age16 – 35
15 or younger don’t seek prenatal care
Birth complications, low birth weight
Over 35: miscarriage, Down Syndrome (father’s age also)
Emotion: stress – can stunt fetal growth
Positive outlook most helpful
Nutrition: lb weight gain
Malnutrition: smaller neurons, brain, child

13. Figure 4.8 The three stages of labor: Stage 1: (a) Contractions of the uterus cause dilation and effacement of the cervix. (b) Transition is reached when the frequency and strength of the contractions are at their peak and the cervix opens completely. Stage 2: ( c) The mother pushes with each contraction, forcing the baby down the birth canal, and the head appears. (d) Near the end of Stage 2, the shoulders emerge and are followed quickly by the rest of the baby’s body. Stage 3: (e) With a few final pushes, the placenta is delivered.
Figure 4.8

14. The Perinatal Environment
Birth Process: 3 step process
Possible Hazards
Anoxia – Oxygen shortage: can be severe
Complicated delivery
Cesarean (“C”) section
Medications: can reach baby

16. The Mother’s Experience
Severe pain, anxiety
77% rate it as positive experience
Psychological factors
Attitude, knowledge, support
Cultural factors

17. Postnatal Depression
Baby Blues, mild, common
Clinical depression: 1/10
Previous depression common
Children of depressed mothers
Insecurely attached, less responsive
Negative to other children

18. The Neonatal Environment
Culture, early socialization, health status
E.g., low birth-weight babies (8% in US)
Less than 5 1/2 lbs
Strongly linked to low SES
Environment: neonatal intensive care
Risk: blindness, deafness, CP, autism, cognitive, and later academic problems
Parenting must be attentive, responsive

19. Risk and Resilience
Not all high-risk infants have problems
Werner: Kauai Longitudinal study (40 yrs)
Findings:
Effects decrease over time
Outcomes depend on postnatal environment
Protective factors
Personal factors
Supportive postnatal environment