Prenatal Development Flashcards
1
Q
stages of prenatal development
A
- Germinal (0-2 weeks): Conception to implantation
- Embryonic (3-8 weeks): Organ development
- Fetal (9 weeks-birth): More development; sensory experiences and learning
2
Q
fetal movement milestones
A
- movement development affects psychological development
- fetus begins to move at 5-6 weeks gestational age (bends head and spine)
- Hiccups begin around 7 weeks gestational age -> tells us that infant’s respitory system is developing
- By 10 weeks, a clear active vs. Rest cycle has emerged (different than, but mimics sleep vs. Rest cycle in newborns -> longer rest periods closer to birth -> creates a U-shaped curve -> little sleep early on, most sleep around birth, less sleep as life goes on)
- Most birth movements by 12 weeks gestational age
3
Q
gestational age
A
time since last menstrual period -> conception is estimated based on this date
4
Q
fetal experience/sensation
A
- Womb is not a vacuum -> fetus has experiences in utero
- includes taste/smell, hearing, touch, and sight
5
Q
fetal gustation/olfaction
A
- Evidence that fetuses can taste/smell in utero
- 3-day-old neonates turn their heads longer toward familiar (mom’s) vs. Unfamiliar (random person’s) amniotic fluid -> shows they can differentiate
- Moms that eat a certain substance (ie. Ginger) have babies who show a preference for that substance in early childhood
6
Q
fetal audition
A
- Most of their auditory experience is exogenous
- Much more robust than fetal vision -> when baby is born, auditory system is much stronger and more developed than visual system
- Hearing is transferred mostly internally through mother’s bones
- Fetal heartbeat changes in reaction to external voices
- Fetal heartbeat is different in reaction to music and speech
- Newborn babies (a few minutes old) can recognize their mother’s language and their mother’s voice
Infants treat a native language differently than they treat a foreign language (as shown by study using suck bursts)
7
Q
fetal vision
A
- What is there to see in utero?
- Not much -> studies show that light does not penetrate the uterus -> it’s quite dark in utero (not much exogenous experience, most of it comes from endogenous stimulation)
- Retinal ganglion cells (type of neuron in retina) fire irregularly by 22 weeks gestational age (provides endogenous visual experience)
8
Q
exogenous vs. endogenous stimulation
A
- Exogenous stimulation = stimuli generated by something/someone other than the organism itself
- Endogenous stimulation = stimuli generated by the organism itself
9
Q
fetal learning
A
- Just like infants after birth, fetuses experience learning in utero
- How do we know?
- Preferences
- Habituation
10
Q
teratogens
A
- Not everything that the fetus experiences in utero is positive for its development
- One of the most widespread causes of fetal abnormalities is the presence of teratogens – external agents that cause damage or death during prenatal development
- Teratogens most affect fetuses during a series of cascading sensitive periods (shown in graph)
- ex. smoking, alcohol, anti-depressants
11
Q
smoking
A
- Smoking during pregnancy is detrimental to the fetus in two main ways:
- Metabolizing the carcinogenic chemicals from mother’s bloodstream into fetus’ bloodstream
- Reduction in oxygen intake -> both from mom’s bad lungs and the smoking itself -> results in slow fetal growth and low birth weight
12
Q
alcohol
A
- Most common and preventable teratogen
- Enters the fetal blood stream without being processed by the mother’s liver -> fetus is getting raw alcohol
- Fetuses are less able to metabolize alcohol than their mothers are -> due both to low tolerance and potentially (depending on where they are in development) may not have enzymes required to break down alcohol
- Alcohol mostly effects women with high education and high SES, which is unlike other teratogens (others mostly affect women with low SES)
- can result in Fetal Alcohol Spectrum Disorder
13
Q
fetal alcohol spectrum disorder
A
- Most severe complication from alcohol consumption during pregnancy
- Facial deformities are common (ie. Low nasal bridge, minor ear abnormalities, thin upper lip, indistinct philtrum)
- Intellectual disability (IQ scores lower than 70)
- Damage to prefrontal cortex (which controls inhibition and attention) -> Behaviour disorders and Attention disability
14
Q
anti-depressants
A
- One study examined how antidepressants affect fetal sound discrimination
- part 1: Fetuses tested at 36 weeks to see whether they could differentiate between “da” vs. “ta” sounds (habituation using heart rate)
- Non-SSRI babies can’t discriminate, SSRI babies can (unlike typical babies)
- part 2: follow up at 6 months with non-native french vowels
- Non-SSRI can discriminate, but the SSRI babies could not (again, unlike typical babies) -> shows an advancement of sensitive period for learning language in SSRI babies -> may or may not be bad, too early to tell. May impede speech/language ability
15
Q
perceptual narrowing
A
- 6-month-olds are good at discriminating those vowels from a language other than their own, but 10-month olds aren’t good anymore -> our ability decreases as we age
- anti-depressant use while pregnant may speed up perceptual narrowing
