Prenatal Development Flashcards
(18 cards)
Stages of Embryonic and Foetal Development
- Zygote: First two weeks of gestation
- Embryo: 3rd week of gestation to end of 2nd month
- Foetus: 2-3 months to birth
- Age of Viability: Period between 22-26 weeks of gestation
- Premature birth: Before full term gestational period of 37 weeks
Foetal Brain
Grows more rapidly than any other organ
* Brain demands a rich supply of nutrients: Protein, fats, iron, etc.
* Supplied through mother’s diet
Teratogens
Any environmental agent that may interfere with the development of the foetus
* Alcohol, smoking, malnutrition, etc
* Comorbidity
Teratogen
Direct Effect of Cocaine Use
- Narrowing of blood vessels to the placenta → Reduces blood supply to the foetus → Affects level of oxygen and nutrients that the foetus receives → Leads to poor growth
- Raise mother’s blood pressure → Premature birth
Teratogen
Wolke & Meyer (1999)
Longitudinal study to measure effects of prematurity on cognitive development
Very pre-term babies:
* At a much greater risk of having a mild or severe learning disability
* Had significantly poorer language skills and problems with grammar and meaning of sentences
* Difficulties in the simultaneous processing of information
Teratogen
Dennis & Najarian (1957)
Orphanage in Teheran
* Children as old as two years were unable to sit securely or stand
* Attributed the delay to the almost total lack of opportunities to explore their environment or to interact with other people
Transnatal Learning
Learning that occurs during the prenatal period which is remembered during the postnatal period
Key Tenets of Foetal Motor and Sensory Development
Foetal Smell and Taste
Maternal food alters the “flavour” of amniotic fluid
* Some evidence that broad maternal food selection engenders broad child’s food consumption
Sensitivities to sweet over other tastes
* Breastmilk = Sweet
* Poor at detecting salty tastes
Smell
* Newborns at 6 days recognise their own mother’s breast milk smell over another mother’s
Key Tenets of Foetal Motor and Sensory Development
Foetal Hearing
Auditory system is mature enough between 23-25 weeks to detect vibroacoustic stimulation at almost all frequencies
* Internal noises are heard more easily (Mother’s heartbeat and voice)
* Foetuses respond to external stimuli (Music, voices, claps)
Heart rate accelerations and body movements
* Recognises mother’s voice
* Discriminate speech sounds
* Discriminate male and female voices
* Discriminate familiar and unfamiliar voices
* Sensitive to white noise, frequency, and intensity changes, vibrations
Key Tenets of Foetal Motor and Sensory Development
Postnatal Auditory Perception
DeCaspar & Spence (1986)
Newborns recognise stories read to them in the womb
* Mothers asked to read same story in last 6 weeks of pregnancy at regular intervals
* High amplitude dummy sucking paradigm
* Infants modified their rates of sucking in the direction that produced the familiar story
Key Tenets of Foetal Motor and Sensory Development
DeCasper et al. (1994)
Recite a rhyme in 35th week of pregnancy
* Familiar rhyme produced a significantly greater change in hear rate
* Babies learn to recognise aspects of spoken language before birth
Key Tenets of Foetal Motor and Sensory Development
Foetal Vision
- Optic nerve formed by 9 weeks
- Retinal layering in period of 12-28 weeks
- Bright light shone on uterus led to increased heart rate from 28 weeks
- Eyelids sealed from 8-22 weeks, but they can still see through
- Gets more light than previously thought
Key Tenets of Foetal Motor and Sensory Development
Reid et al. (2017)
Foetal Vision
Foetal Response to Visual Stimuli
* Orienting more to face like configuration as compared to non face like configuration
* Head turning gaze direction paradigm
Key Tenets of Foetal Motor and Sensory Development
Johnson & Morton (1991)
Foetal Vision
Newborn Face Preference Studies
* Newborns can distinguish face from non face like stimuli
* Faces are attested to from birth with preference for upright more than inverted
Nativist Theory
Attention to Faces
Humans are born with abstract face schema
Empiricist Theory
Attention to Faces
Preference to faces emerges developmentally through associative social learning
* Infants associate a proper face of caregivers with positive outcomes
Key Tenets of Foetal Motor and Sensory Development
Physical and Motor Development
Organised embryonic behaviours at 8-12 weeks of gestation
* Expanding and contract links, kicking feet, benign arms, forming fists curling toes, sucking thumbs, opening mouth
* All core physical characteristics are well in place by 7 months
Remaining physical changes relate to
* Increase in fat tissue and muscle size
Key Tenets of Foetal Motor and Sensory Development
Yamakoshi & Takeshita (2006)
Physical and Motor Development
Inter-Sensorimotor Action Anticipation
* Arms and hand movements toward the face were examined at 5-9 months of gestation
* More than half of the observed arm movements resulted in hand touching the mouth either directly or indirectly
* Movements were anticipatory: Opened their mouths before their hands came in contact
