Effects of Prenatal Stress

When is stress most likely to be harmful

highly intense or traumatic (war, serious illness), chronic or long term (poverty or pandemic), and do not have control or ability to change (poverty, racism, natural disaster)

When is stress more likely to be helpful

acute or short term (interview, planning wedding), when individual has resources to adapt to resist the challenge, and ability to control or change stressor

Effects of prenatal stress: Birth complications

shorter gestational length and premature birth, low birthweight (increased likelihood of health problems) and increased risk for miscarriage

Effects of prenatal stress: emotional/behavioral outcomes

more difficult temperament, negative effect and crying, higher anxiety in childhood, and more behavioral problems

Effects of prenatal: cognitive and motor development

lower motor and cognitive development (attention regulation)

Effects of prenatal stress: psychiatric or neurodevelopmental disorders

increased risk of ADHD in childhood, increased risk for neurodevelopmental disorders (autism and schizophrenia), increased risk for mood disorders (anxiety and depression)

Timing of prenatal is crucial as it can lead to

permanent changes

fetal programming hypothesis

stressors occurring during critical periods of prenatal development may lead to permanent changes in brain development and risk for long term outcomes

what were the two studies that showed the differences based on timing of prenatal stress

Kinney et al and Torche & Kleinhaus

Torche and Kleinhaus studied effects of earthquake on gestational length: methods and results

pregnant women in Chile who experienced earthquake compared to women that were nearby but were not affected (cross-sectional); those who experienced earthquake while they were 3 months pregnant had shorter gestational lengths

Kinney et al studied stressor of storm/hurricane exposure on development of autism disorder: methods and results

used objective index (weather and birth record data) to see when during pregnancy the storm occurred; mothers exposed to hurricane showed that those who were 5-6 months (mid gestation) had highest risk of developing autism bc during this time neuronal migration occurs & 9 months is peak for synapse formation as it also shows increased levels then

mechanisms of prenatal stress #1

prenatal stress reduces blood flow to fetus because of activation of SAM and HPA axis (sends oxygenated blood away from fetus)

mechanisms of prenatal stress #2

involves HPA axis and cortisol

increased risk of premature birth because

if a pregnant woman is activating HPA axis repeatedly, more CRH and cortisol is produced (normally CRH signals when to go into labor)

effects of fetal brain development because

higher maternal cortisol levels are associated with higher fetal cortisol which is neurotoxic and disrupts growth of neurons and synaptic connections