Prenatal Development and Hazards Flashcards
What are the 4 stages of prenatal development
- Cell division.
- Cell migration. Cells move away from their point of origin
- Cell differentiation. Embryonic stem cells specialise their structure and function
- Death. Cells disappear where they are not needed
Describe Fetal Behaviour
5-6 weeks. Moves spontaneously
7 weeks. Hiccups and swallowing, prepares for drinking and digestive system develops. Moves limbs
10 weeks. Fetal breathing. Amniotic fluid taken in
Describe Fetal Experience
Sight. Minimal visual experience. Rub faces and suck thumb. Bumps against uterus
Taste. Amniotic fluid has a taste. Prefer sweet tastes. Drunk more fluid when it was sweetened
Smell. Smells like what mother has eaten. Comes in to contact with odour receptors when fetus breathes.
Hearing. Womb is noisy e.g breathing, blood pumping, digestion, mothers voice. Heart rate decelerates when hearing mothers voice.
Describe Fetal Learning
Habituation. 30 weeks fetuses show habituation to auditory and visual stimuli. Heart rate increased to mothers voice and decreased to other woman’s voice
Memory. Can remember smell of amniotic fluid. Turn head to side of pad soaked in their own fluid. Mother drank carrot juice near end of pregnancy - baby responded more positively to cereal in carrot juice
Auditory preference - newborns prefer mothers voice distorted like to would sound it in the womb. Prefer to listen to the language spoken when they were in the womb
What are teratogens and how are they a prenatal hazard
Environmental agents that may harm a fetus.
Only cause damage during sensitive periods.
E.g thalidomide. Caused birth defects of missing limbs if taken during 4th to 6th week.
How are drugs a prenatal hazard
Over the counter drugs - accutane can cause serious birth defects and death
antidepressants - negative effects of SSRIs. Inconclusive evidence. May be low birth weight, preterm birth and withdrawal
Opioids - fetus can become addicted. Low birth weight, seizures, problems breathing and feeding
Illegal drugs - marijuana. Doubles risk of stillborn birth.
What maternal factors are prenatal development hazards
Age - babies born to mothers 15 and under are more likely to die before 1. Older parents - more likely to have chromosomal abnormalities and autism
Nutrition - not enough folic acid can lead to neural tube defect. Malnutrition can lead to smaller brain. Difficult to isolate from other factors of poverty
Disease - e.g rubella. Malformations, deafness, blindness. Genital herpes - blindness and death. AIDS - can be passed on. Schizophrenia - more likely if mother had influenza during first trimester
Maternal emotional state - higher stress higher levels of fetal movement, more behaviour problems, more emotional problems
What are states of arousal in infants
Sleep - most of it is R.E.M. Activates the visual system. May be learning when they’re asleep. Can remember sounds played when asleep.
Crying - adaptive. Aids survival. Normal behaviour, increases until 8 weeks. Soothing helps, repetitive stimuli e.g rocking, swaddling. Cry less when interacting with adults.
What are negative outcomes at birth
Mortality - low in developed countries. Less poverty, famine, illnesses
Low birth weight - premature. Can be due to teratogens e.g smoking, drinking, drugs, pollution. More common in multiple births. Can affect babies in later life e.g poor academic achievement, poor behaviour, psychiatric issues. Most end up normal.
How is smoking a prenatal hazard
decreased oxygen to fetus. Slower growth, low birth weight, SIDS, low IQ, ADHD, hearing loss
How is alcohol a prenatal hazard
Alcohol - directly and indirectly, through bloodstream and amniotic fluid. Fetal alcohol syndrome. Small eyes, flat Cupid’s bow, attention problems, intellectual disability
How are teratogens a prenatal hazard
Have a dose response relationship - more exposure worse effects.
Occur in combination e.g poverty, poor nutrition, poor healthcare, pollution, stress
Can effect fetal programming - Dutch winter hunger women gave birth to babies of normal weight. Later in life had obesity issues. Metabolism permanently set in the womb
