Prenatal

BRAIN DEVELOPMENT

Prenatal Influences

Teratology

  • Teratology: The study of negative effects on children resulting from environmental influences.

  • Teratogens: Environmental factors that adversely impact developing fetuses. Examples include:

    • Drugs

    • Chemicals

    • Radiation

  • Teratogens can pass through the placenta and negatively affect fetal development.

Disease and Prenatal Timing

  • The effects of diseases depend on when they are contracted by the mother or the fetus:

    • May cause slight to severe effects.

    • Exposure may impact the mother differently than the fetus.

Age as a Risk Factor

  • Maternal age plays a critical role in prenatal development:

    • Teenage mothers and women over age 35 are at greater risk for complications.

Nutrition

  • Poor nutrition during weeks 10 to 20 of pregnancy adversely affects brain development and can lead to:

    • Impaired bone and teeth formation

    • Low birth weight

    • Anemia (poor quality blood)

    • Mental deficiencies

Stress

  • Evidence regarding stress effects on newborns is inconclusive:

    • Some studies suggest it may influence behavior during infancy.

Genetic Abnormalities

Causes and Frequencies

  • Major causes of genetic abnormalities involve:

    • Union of sex cells and random gene distribution.

    • Genetic diseases affecting inheritance.

  • In the U.S., about 3% of babies born with genetic abnormalities lead to 20% mortality from these conditions.

Increase in Incidence

  • There has been a rise in genetic abnormalities since the 1950s, possibly linked to prescription and non-prescription drug use.

Forms of Genetic Transmission

  • Genetic abnormalities can be transmitted through:

    • Carriers

    • Recessive and dominant gene transfer

    • Gene interactions (gene + gene, gene + environment)

    • Defective chromosomes.

Specific Genetic Disorders

  • Sickle Cell Anemia: More common in individuals of African heritage; connected to malaria.

  • Down Syndrome: Caused by an extra 21st chromosome; risk increases with maternal age (1 in 1000 for women in late 20s, 1 in 50 for women in late 40s).

  • Klinefelter's Syndrome: Characterized by tall stature, small testicles, sterility, and below-average intelligence.

  • Turner's Syndrome: Features include short stature and limited sexual development.

  • Hemophilia: Disorder where blood does not clot properly; more prevalent in the African American population.

  • Cystic Fibrosis: Causes mucus accumulation in lungs; higher incidence in European North Americans.

  • Phenylketonuria (PKU): Amino acid buildup damages the nervous system.

  • Tay-Sachs Disease: Leads to nervous system degeneration, typically resulting in death by preschool age.

Prenatal Heredity & Environmental Factors

  • Gestation period: Lasts about 266 days (38 weeks).

  • Development occurs sequentially from conception to delivery (P.C.C.E.S.):

    • Order: Physical, Cognitive, Social, Emotional development.

  • Nature and nurture impact the developmental process.

  • Prenatal care and postnatal care are crucial for healthy development.

  • Traits and characteristics are inherited through genes grouped in chromosomes:

    • Combined from 23 chromosomes (mother) + 23 chromosomes (father) = Individual.

  • Environmental factors can influence development both positively and negatively.

Prenatal Development Stages

  • Three Stages:

    • Germinal Stage: Conception to 2 weeks.

    • Embryonic Stage: 2 weeks to 8 weeks.

    • Fetal Stage: 8 weeks to birth.

  • Critical Periods:

    • Specific times in development that are crucial for influence impact.

    • Development of systems and organs occurs in an orderly manner.

    • Health and nutrition are key components during these stages.

Prenatal Testing

  • Types of prenatal testing methods:

    • Chorionic villi sampling

    • Ultrasound

    • Amniocentesis

Birth Process

  • Leboyer Method: Advocates for a gentle birth with minimal trauma.

  • Lamaze Method: Focuses on breathing and relaxation techniques, promoting a natural approach.

  • Stages of Birth:

    • Dilation

    • Birth

    • Expulsion of placenta.

APGAR Scale

  • A rating scale to assess the health of neonates at birth:

    • A: Appearance (skin color).

    • P: Pulse (heart rate).

    • G: Grimace (response to light and pain).

    • A: Activity Level (motor responses and tone).

    • R: Respiration (breathing efforts).

  • Assessment ratings:

    • 7 or above: Doing well.

    • 5-7: May require additional care.

    • 4 or below: Life-threatening condition.

  • Impact of prematurity and low birth weight on overall development emphasizes understanding diversity in children's developmental needs.

The Neonate

  • Age: From birth to 1 month.

  • Adjustment Period: Adjustment from womb to birth, managing vital functions post-delivery.

  • Average Weight: Between 2.5 kg and 4.3 kg.

  • Average Height: Ranges from 48 cm to 56 cm.

Appearance and Body Functioning

  • Vernix: A protective covering on the skin post-birth.

  • Body Hair: Presence of fine facial and body hair.

  • Skull Shape: Misshapen head due to molding effect during birth; soft spots present.

  • Breasts and Genitals: May be temporarily enlarged.

  • Eyes: Appear glazed over.

  • Initial Reflex Actions: Include crying, snorting, sneezing, coughing.

  • Cardiovascular System: Begins function utilizing lungs.

  • Nourishment and Temperature Regulation: Managed during the transition from womb to external environment.

Infant Behavior and Reflexes

  • Reflexes: Automatic responses to specific stimuli in the environment.

  • Examples of Reflexes: Actions such as sucking, grasping, and stepping that are inherent abilities in infants.

Neuroscience of Behavior

  • Neuroscience: The interdisciplinary study focusing on how brain activity shapes individual behaviors and capabilities.

Methods of Study in Neuroscience

  • Techniques include:

    • Naturalistic observation

    • Clinical research

    • Technologically-based applications (CT, MRI, PET scans).

  • Imaging technologies provide insights into:

    • Nature and structure of the brain.

    • Active brain areas.

    • Diagnoses of disorders and abnormalities.

    • Effects of environmental stimulation on brain development.

Terms to Understand in Neural Development

  • Critical/Sensitive Period: Optimal times for receiving necessary inputs to strengthen neural connections.

  • Central Nervous System (CNS): Composed of the brain, brain stem, spinal cord, with essential neural functions.

  • Neurons: Basic nerve cells in the nervous system crucial for communication; develop and branch throughout life.

  • Synapses: Communication links enabling interaction between neurons; strengthened or discarded links based on use.

  • Myelination: Formation of the myelin sheath around neurons, enhancing speed and accuracy of signal transmission.

  • Stimulation: External influences affecting brain development, involving reactions to sensory inputs.

  • Wiring or Sculpting: Refinement of neural networks through strengthening or discarding connections, occurring predominantly in early childhood.

Neuro Research Findings in Early Childhood

  • Early experiences crucial for enduring neural structures; strong connections are formed in infancy.

  • Infants initially create a vast number of synaptic connections which will later get refined.

  • Neonates utilize twice the energy of an adult brain.

  • Proper emotional and sensory stimulation creates a foundation for lifelong learning.

Principles of Brain Development

  • Environmental input shapes brain wiring through sensory experiences (sight, sound, taste, touch, smell).

  • The brain operates on a "use it or lose it" principle regarding neural connections.

  • Early relationships are foundational for emotional and social brain development.

Overview of Brain Function

  • The brain's development is influenced not only by genetics but also by experiences before and after birth.

  • Key to cognition, emotional regulation, language acquisition, and social interaction.

Prenatal Brain Development

  • In the first month post-conception, the embryo forms key layers, including the ectoderm that becomes the CNS.

  • By week 4, the main brain structures are established.

  • Maternal nutrition and avoidance of teratogens are vital for healthy brain development.

Brain at Birth

  • Babies are born with approximately 100 billion neurons, most of which are not interconnected at birth.

  • Post-birth, neurons engage in rapid activities forming pathways; some connections are strengthened while others are lost (known as 'wiring' or 'sculpting').

Creating Optimal Environments for Brain Development

  • Key factors for fostering healthy brain development include:

    • Breastfeeding: Optimal nutritional source for brain growth.

    • Healthy Attachment: Essential for emotional security.

    • Responsive Care: Influences which neurons thrive.

    • Protection from Harm: Ensures a safe developmental environment.

Breastfeeding Benefits

  • Breast milk is unique, species-specific, and rich in fatty acids critical for brain development.

  • It adapts to the needs of both mother and infant, containing vital nutrients and colostrum.

  • Breastfeeding reduces the risk of illnesses and conditions like SIDS.

  • The World Health Organization recommends exclusive breastfeeding for the first six months, continuing with complementary foods until at least two years of age.