Fostering Healthy Prenatal Development

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Fostering Healthy Prenatal Development
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Outline

• Preconception
• Stages of development from conception to birth
• What can interfere with healthy development
• Teratogens
• Alcohol
• Low Birth weight
• Prevention
• Cool Tool http//www.zerotothree.org/baby-brain-m
  ap.html

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Timelines of Human Prenatal Development
Tri- mester
1st trimester
2nd trimester
3rd trimester
Prenatal week
Brain Growth Spurt (Dobbing) --gt 2 yrs
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3
13
5
7
9
15
17
19
21
23
25
27
29
31
33
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39
35
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birth
Video



1 Neural Induction
5 Specialization
2 Proliferation
Cowan Brain Dvlp
7 Cell Death
4 Aggregation
6 Connections
3 Migration
8 Elimination of Connections
stages 5, 6, 7, 8
continue
postnatally
FETUS
EMBRYO
Ovum Embryo Fetus
to birth
wks 3 - 7
OVUM
birth
viability
"quickening"
Tri- mester
3rd trimester
1st trimester
2nd trimester
wks 27 - 39
wks 1 - 13
wks 14 - 26
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Stages of prenatal development

• 1st trimester Organ development Nervous system
• Cells multiply
• Cells specialize and migrate to where they should
  be to be part of certain organs
• 2nd trimester
• Nerve cells proliferate and form connections
• External organs continue to be laid down
• 3rd trimester
• Brain growth spurt
• Can hear sounds
• Getting ready to come out lungs very immature

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Cowan's Eight Stages in Brain Development

• 1. Neural Induction ( days 16-23)
• 2. Cell proliferation
• Begins once neural tube has closed off.
• Migration
• 4. Aggregation

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Cowan's Eight Stages in Brain Development (cont.)

• 5. Specialization of immature neurons (16-25
  wks)
• a. elaboration of processes
• b. adoption of mode of transmission
• 6. Formation of Connections
• 7. Selective Cell Death
• 8. Selective Elimination of Connections

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Fig.5
FETUS (wks)
EMBRYO (wks)
OVUM
Central Nervous System
Heart
Arms
Eyes
Legs
Teeth
Palate
External genitalia
Ears
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What can interfere with healthy development

• Teratogens literally means creates monsters
• Now used to mean anything that mother exposed to
  that interferes with prenatal development in ways
  that cause
• Birth defects (visible at birth)
• Behavioral Difficulties (behavioral teratogens)
• Low birth weight
• Prematurity
• Low weight for gestational age

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1. Teratogens

• How effect fetus/embryo
• directly as in radiation
• Cross from mothers body through placenta
• Alcohol, infections
• Affect genes environment
• Examples
• Thalidomide (drug)
• Infections -- Rubella (measles)
• Radiation
• Alcohol

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Thalidomide WarningLabel
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Thalidomide Deformities
Normal development
Hands
Feet
Effects of time of exposure (3.5 - 7 wks
gestational age) on limb deformities
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Thalidomide Deformities
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Effects of teratogens

• Critical periods of exposure
• Embryo or fetus vulnerable to specific problems
  during specific times when undergoing a
  particular developmental process. (e.g., female
  fetus may have genital malformations if exposed
  to androgens ltmale sex hormonegt during 10th week
  of gestation).
• 1st trimester (especially 1st two months)
  organs, limbs, shape)
• 2nd 3rd trimester brain size (less visible
  effects) size of fetus
• Vulnerability of fetus (some tougher than others)
• General health of mother

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Fig.5
FETUS (wks)
EMBRYO (wks)
OVUM
Central Nervous System
Heart
Arms
Eyes
Legs
Teeth
Palate
External genitalia
Ears
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3rd Week of Development
Neural Induction
embryonic mesoderm
neural groove
neural fold
neural plate
brain
primitive knot
first missed menstrual period
neural groove
primitive streak
somite
somite
notochord
2-3 mm
trilaminar embryo
heart tubes
prim.streak
thyroid developing
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4th Week of Development
Proliferation Migration
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4th Week of Development
Proliferation Migration
hydrocephaly anencephaly hydroanencephaly
spina bifida
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Neural Tube Defects
Spina Bifida
Day 22
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Radiation Interferes with cell migration and
aggregation -- stop too soon
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Rat Brain Normal Development
Proliferation -- Migration -- Aggregation
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Radiation on Days 13-14
Proliferation -- Migration -- Aggregation
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Radiation on Days 16-17
Proliferation -- Migration -- Aggregation
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Alcohol Interferes with migration.Cell dont
stop
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Alcohol as a Teratogen

• Negative effects throughout gestation
• Neurological Damage
• Retarded Physical Growth
• Face and organ malformations
• Unknown whats a safe dose
• Leading known environmental cause of mental
  retardation
• 5-10 of women of child-bearing age have alcohol
  problem

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Alcohol-related birth defects

• Facial features underdeveloped midface

Kathy Sulik
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Alcohol-related birth defects

• Underdeveloped brain

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Fetal Alcohol Syndrome (12,000 a year in U.S.)

• Mild retardation -- IQ 65-80
• Difficulty with reasoning and planning
• Distractable
• Dont learn from mistakes
• Indiscriminate affection
• Verbal gt Reasoning
• (Anne Streissguth, U of Washington c.1970)

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Fetal Alcohol Spectrum Disorder (36,000 a year in
U.S.)

• More common but less severe form of the syndrome
• Effects evident in behavior only
• Problems with attention
• Inhibition difficulties (start cant stop)

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• FAS 843

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Learning about the effects of alcohol

• Correlational studies in humans
• Correlations show whether two things tend to be
  found together
• Dont prove cause
• Experimental studies with animals

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Correlational studies in humans Limitations

• Difficult to accurately estimate level of alcohol
  exposure.
• Amount mother ingests
• - Amount fetus/embryo exposed to
• Cant rule out alternative causes of problems
  child might be showing Correlated risks
• Difficult to study effects of exposure during
  specific periods

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Experimental studies with animals

• Advantages
• Control when and how much exposed.
• Compare to control group similar except for
  exposure to alcohol
• Infer that alcohol causes differences in
  offspring.
• Look in a fine grained way at how alcohol
  exposure disrupts brain development.
• Disadvantages
• Unclear how findings apply to humans especially
  for things that only humans do.

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Findings from animal studies

• Ist trimester
• Facial malformations, worse for growth and
  behavior than later exposure.
• Effects on behavior even in the absence of
  obvious physical defects.
• Effects to nervous system due to exposure in only
  2nd and 3rd trimester.

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2nd semester

• When nerve cells are generated and go to
  appropriate regions of the brain
• Effects
• Nerve cell generation delayed
• Fewer produced.
• Nerve cells dont go where they are supposed to
  go.
• Unusual cell formations in
• hippocampus learning,memory emotion
• cerebellum motor ability

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3rd trimester

• Interferes with brain growth spurt
• Brain weight head circumference reduced
• Fewer cells in cerebellum hippocampus
• These anatomical changes are related to animal
  equivalent of hyperactivity and learning deficits.

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Humans What can we tell about effect of alcohol
on behavior

• Early, heavy drinking leads to most severe
  problems
• mental retardation
• sensory deficits (vision, hearing)
• motor problems
• Facial abnormalities 1st 8 weeks (comparison of
  women who stopped or continued M 24 drinks per
  week)

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Human Behavior cont.

• Even in the absence of physical effects
• learning and attention problems.
• Moderate early drinkin leads to more subtle
  learning difficulties and attention problems.
• Hyperactivity, language difficulties, motor
  deficits greater when Mom drank through pregnancy
  than stopped after 1st trimester
• Weight, length, head circumference affected by
  drinking later in pregnancy
• Being alcohol free during 3rd trimester allows
  growth catch up.

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FASD Adults

• The following secondary effects were ascertained
  from life history interviews of 415 FASD affected
  individuals using 450 questions
• Dr Anne Streissguth, et al, University of
  Washington

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Secondary Disabilities

• Mental health problems 94
• Disrupted school experiences 43
• Easily victimized 72
• Trouble with the law 60
• Inappropriate sexual behavior 45
• Alcohol and drug problems 50
• Problems parenting
• Problems living independently

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FASD and Activities of Daily LivingStreissguth
et al. Longitudinal Study (1996)

• Sample of adults age 21 were unable to
• Manage money 82
• Make daily living decisions 78
• Obtain social services 70
• Get medical care 68
• Handle interpersonal relationships 57
• Grocery shop 52
• Cook meals 49
• Structure leisure activities 48
• Stay out of trouble 48
• Maintain hygiene 37
• Use public transportation 24

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Implications for intervention

• FAS and FAE are common preventable problems.
• How can we develop interventions that work?
• Type of intervention
• Primary, secondary, tertiary
• How should be target?
• Getting knowledge to people
• Motivation to change
• Learning from people who have changed

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2. Preventing low birth weight babies

• Who has low birthweight babies
• Poverty nexus of risk
• Multiple births through infertility treatment

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Why? At risk for

• medical problems
• developmental problems such as cerebral palsy
• higher risk of mortality

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Role of life style factors in preventing low
birth weight
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Nutritional and weight gain

• Risk factors
• Low income/limited food budgets
• Stress and distress
• Lack of knowledge about proper nutrition
• Smoking, alcohol

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Life style choices Cigarette smoking, alcohol,
caffeine, and illegal drugs

• Risk factors
• Stress and distress
• Lack of knowledge about their effects
• Lack of support for stopping addictive behavior
• Quitting smoking at any point has positive effect
  on birth weight.Smoking after birth increases
  childs risk of respiratory problems (most women
  who quit during pregnancy start again after the
  childs birth).

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Stress

• neuroendocrine functioning
• depresses immune system
• Affects health behaviors
• decreases likelihood of prenatal care
• increases likelihood of smoking, drinking
• Anxiety may increase metabolism
• Depression affects appetite, sleep

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Employment

• Benefit health insurance, income
• Possible problems
• exposure to toxins
• work related stress and fatigue
• work overload may interfere with eating
  regularly

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Domestic violence

• Physical abuse can lead to
• early onset of labor
• neglect of prenatal care, chronic medical
  conditions

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Sexually transmitted diseases

• various infections linked with low birth weight
  and preterm babies.

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Directions for prevention and intervention

• Learn from women who despite living in
  economically depressed or stressful situations,
• dont engage in high-risk behaviors that may have
  a detrimental effect on their child during
  pregnancy
• who have been able to change.
• Apply the lessons learned to intervention
  programs.

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Change

• Pregnancy is an opportunity for change.
• Women want healthy babies
• More likely to
• seek information about healthy behavior
• make changes in their own lives during or before
  pregnancy.
• Benefits
• OWN HEALTH SHORT TERM AND LONGTERM
• INCREASES LIKELIHOOD OF HEALTHY BABY
• POSTNATAL HEALTH OF BABY
• IMPROVES HEALTH OF ENTIRE FAMILY (CHANGES IN
  DIET)

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Barriers to change

• Life circumstances that require focus on
  day-to-day survival.
• Unavailability of health care.
• Development of addictive behaviors long before
  pregnancy makes it hard to stop during pregnancy
• Case of smoking
• ads targeting young women
• societal concern about weight