Studied by 5 people
Chapter 3
Prenatal Development - Timeline
average of 38 weeks (9.5 months) for fertilized egg to turn into a newborn human
22-28 weeks (5.5-7 months) — age of viability
fetus has working senses and will survive if born now
How can we test fetal hearing?
monitor fetal heart rate
Kisilevsky et al. (2003): Fetal Hearing Study
can fetuses remember and recognize their mother’s voice and differentiate between familiar and unfamiliar voices?
tested 60 fetuses (and their mothers) for 6-minute testing sessions
women came in to read poems
recordings were played for fetuses
2 groups
mother’s voice condition
stranger’s voice condition
Measured heart rate before, during, and after voice recording
Fetal Hearing Study — Results
mother’s voice group
heart rate increased more during recording compared to baseline
stranger’s voice group
heart rate stayed pretty consistent, maybe even small decrease, during recording compared to baseline
conclusion: fetus can differentiate mother voice and stranger voice
Fetal Taste
food that the mother eats is transmitted to amniotic fluid which the fetus swallows
suggestion that a baby prefers foods that they tasted in the womb or when being breastfed
Mennella et al. (2001): Fetal Taste Study
do infants prefer food that their mother ate during pregnancy or breastfeeding?
tested 46 pregnant mothers (last trimester) who delivered healthy babies and breastfed them
3 groups
group CW
group WC
group WW
Tested infants in all 3 groups for preference between carrot-flavored vs plain cereal
Fetal Taste Study — group CW
mothers drank only carrot juice in the last trimester of pregnancy
mothers drank only water in the first months of lactation
Fetal Taste Study - group WC
mothers drank only water in the last trimester of pregnancy
mothers drank only carrot juice n the first months of lactation
Fetal Taste Study - group WW
mothers drank only water in the last trimester of pregnancy
mothers drank only water in the first months of lactation
Fetal Taste Study - Results
Based on 3 measures
negative faces - how many times infants made a negative facial expression while eating
mother’s perception - mother watched video and got them to say what they thought their child thought of the cereal
intake - how much did they consume
calculated differences between reactions to both cereals
all measures indicate that exposure to tastes during pregnancy or breastfeeding effects the child’s food presence
Influences on Prenatal Development
Nutrition
Stress
Parental Age
Teratogens
Nutrition
the fetus relies on nutrients from the mother
mothers often need to increase calories by 10-20% to support themselves and the growing baby
need to eat enough food and good quality food
malnutrition during pregnancy may result in long-term developmental challenges
recommend supplements (prenatal vitamins) for extra proteins, vitamins, minerals
e.g., folic acid (folate) important for development of nervous system, spinal cord, spine
Stress
high levels of chronic stress is associated with poorer outcomes for your baby (stress here and there is ok)
higher maternal stress during pregnancy → once baby is born they are harder to soothe, lower attention, problem behaviour
women stressed about their pregnancy tend to have underweight babies
Why does this happen
genetics
environment (babies learn from their environment to be stressed)
stress can secrete hormones that effect oxygen reaching the fetus
people who were pregnant and had connections to 9-11 had higher levels of cortisol and so did the babies
evidence of generational effects of trauma
Transgenerational Trauma - Epigenetics
epigenetics
the continuous interplay between genes and our environment
genes are modified and either turned on or turned off
changes in gene expression found in trauma survivors
and their children who were not exposed to the trauma
e.g., 9-11 survivors, holocaust survivors, residential school survivors
Parental Age
age of birth of first child has been increasing (average age in Canada is 29)
as of 2012: women giving birth in their 30s has doubled from 1980
age range of 20-30 is the best time for fertility and personal lives
highest fertility in 20s
more pregnancy complications after 35 years of age (decrease in fertility, increase in complications)
not a hard deadline, just harder after this age
Why are women having kids later?
advancing reproductive technologies
NB: infertility treatment fund gives up to $5000 for NB residents with diagnosis of fertility problems
freezing eggs: you can have kids later with younger, healthier eggs (super expensive!!)
Teratogens
an agent that causes abnormal prenatal development
diseases (e.g., HIV, AIDS, genital herpes, syphallis)
can directly attack baby through placenta or can be effected if they line the birth canal
certain drugs (e.g., aspirin, caffeine, alcohol, nicotine)
can reduce oxygen and nutrients to baby
fetal alcohol syndrome
second hand smoke
marijuana use can have effects similar to nicotine (less researched)
environmental hazards (e.g., contaminated water, lead, x-rays)
APGAR Score
5 vital signs of life - scored on a scale from 0-2
A-Activity: moves limbs actively
P-Pulse: at least 100 beats per minute
G-Grimace: reflex by crying from irritating stimulus (pinch baby)
A-Appearance: lack of blue-grey skin colour
R-Respiration: strong breathing and crying
highest score is perfect 10
score of 7 or more = no worries
score between 4-6 = might be something wrong
score between 1-3 = serious, life threatening issue
Newborn Reflexes
unlearned responses that are triggered by a specific stimulation
indication of if the nervous system is working properly
thought to help infants survive (evolutionary reason)
5 examples
palmar reflex
moro reflex
rooting reflex
sucking reflex
stepping reflex
at some point in development we lose these reflexes and start to do these things voluntarily
Palmar Reflex
if you place something in the palm of a baby’s hand they will automatically wrap their fingers around and hold on
Moro Reflex
when you put a baby down and their head falls back or they feel like they’re falling they will reach their arms out to grab onto something
Rooting Reflex
when you stroke a baby’s cheek they will turn to face stimulus and open mouth to feed
Sucking Reflex
put something in their mouth and they will automatically start sucking
Stepping Reflex
if you lift a baby up and put their feet on the ground they will move their legs around like they’re walking
Sudden Unexpected Infant Death
could be due to these reflexes starting to fade away too early before they have enough voluntary control to complete these actions
Newborn Sleep
sleep 16-18 hours daily
sleep in “nap cycles”
cycle between awake/asleep every 4ish hours
gradual shift to more “night sleep”
Baby Blues
irritation, resentment (towards baby and maybe partner), and crying after having a baby
stress of the new baby and bodily changes/recovery after childbirth
hormonal changes
experienced for about 1-2 weeks
some evidence that fathers can also experience this
Postpartum Depression
feelings of irritability, low self-worth, disturbed sleep, poor appetite, lack of interest
more serious and lasts longer than baby blues
lasts for months after giving birth
less common but still about 10-15% of women report experiencing this
may not reciprocate/provide emotional range desired by infant
Still Face Paradigm
react normally with infant, using facial expressions and then stop showing any emotion and see how baby reacts (baby gets very stressed when mom stops interacting but returns to normal when mom responds again)
same effects in fathers
Greater Risk of Postpartum Depression if…
you experienced depression before pregnancy
coping with other life changes during pregnancy or early in newborn stage
e.g., recent death in the family, made a big move (new house)
unplanned pregnancy (particularly an unwanted pregnancy
lack of support from others during pregnancy and in early newborn stage
*mothers should seek help and be taken seriously
Note 
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