Chapter 4 - Prenatal Devel. and Birth Flashcards
what are the 3 stages of prenatal development
period of zygote, embryo, and fetus
how long does the period of the zygote begin and last
begins with fertilization and lasts about 2 weeks (when fertilized egg implants itself in wall of uterus)
what is a fertilized egg called
zygote
what is the period of zygote mainly characterized by
rapid growth through cell division
in zygote period, how often does cell division occur
every 12 hours
by the end of the first week, what happens to the zygote and what is next
recheas the uterus
-implantation
what is implantation, how long does it take and what does it trigger
burrowing of zygote into uterine wall and connects to the mothers blood vessel
-takes about a week
-triggers hormonal changes that prevent menstruation
what is the germ disc of a zygote
small cluster of cells near center that eventually develops into the baby
what is the layer of cells of the zygote closest to the uterus called
placenta
what marks the end of the period of the zygote
implantation and differentiation of cells
when does the period of the embryo begin and end
once zygote completely embeds istelf in uterine wall
-begins around 3rd week after conception and lasts until end of 8th week
what is the period of the embryo mainly characterized by
development of body structures and internal organ
what are the 3 layers that form in the embryo at the beginning of th eperiod and what will they become
-outer: ectoderm - hair, outer layer of skin and NS
-middle: mesoderm - msucles, bones, and circulatory system
-inner: endoderm - digestive system and lungs
in what period of prenatal development can you begin to see eyes, jaw, arm and legs
period of the embryo
where does the embryo rest inside the mother
amniotic sac
what is the purpose of amniotic fluid
to cushion embryo and maintain constant temperature
what allows nutrients, oxygen, vitamins, and waste products to be exchanged between mother and embryo
the villi from the umbilical blood vessels that lie close to the mothers blood vessel
what are the 2 important principles of grwoth in the period of the embryo
-cephalocaudal: growth from the top and extending downward
-proximodistal: growth from the center and extending outward
what is the longest phase of prenatal developmetn and how long does it last
period of the fetus
-from the ninth week after conception until birth
what is the period of the fetus mainly characterized by
child becomes much larger and its bodily systems begin to work
at what period of prenatal development can the mother start to feel the baby
period of the fetus
at 4 weeks after conception, during the fetus period, what main thing happens
-flat set of cells curls to form a tube
-at one end it swells to form brain
-rest forms spinal cord
describe the brain at the beginning of the fetus period
-has distinct structures and begun to regulate body functinoing
-all regions of brain grow especially cerebral cortex
what is the cerebral cortex
folded surface of the brain that regulates many important human behaviours
when do male embryos develop testes and females develop ovaries
near the end of the embryonic period
when do female fetuses develop a vagina and labia
thrid month
what secretes the hormone that causes cells to develop into a penis and scrotum and what happens if this hormone is not secreted
-testes
-will have female genitalia
when do eyebrows eyelashes and scalp hair emerge
in fift and sixth month
what is vernix
thick, greasy coating on skin that protects baby during gestation
what are the 3 general risk factors of prenatal development
nutrition, stress and a mothers age
most pregnant women need to increase their intake of calories by how much and why
10-20 precent
-to meet the needs of prenatal development
when does weight gain of th emotehr tend to be higher during pregnancy and why
second half of pregnancy
-as fetus grows
what are the 3 areas that cause a womens weight gain during pregnancy
-weight of baby, placenta and amniotic fluid
-increases in a womens fat stores
-increased volume of blood and size of her breasts and uterus
what 2 vitamins are important for a babys NS
-folic acid
-B vitamins
what are babies at risk for if mothers do not consume enough folic acid, describe this disorder
spina bifida
-embryos neural tube does not close properly during first month of pregancy
-neural tube develops into brain and spinal cord, result is permament damage to spinal cord and NS
wwhat are symptoms of spina bifida
many children need crutches, rbaces or wheelchairs
what happens to infant if pregnant women does not provide adequate nourishment
likely to be born prematurely and to be underweight
in prenatal development, when is the time of rapid brain growth
last few months of pregnancy
correlational studies show what about women who report greater stress during pregnancy
give birth early or have babies who weigh less than average
when is the optimal age for having a child
25 and 34
what is thalidomide
agent that disrupts normal prenatal development
-pregnant women were prescribed this to help them sleep and control symptoms of nausea
potential consequences for developing baby when pregnant mother has AIDS
-frequent infections
-neurological dirsorders
-death
potential consequences for developing baby when pregnant mother has cytomegalovirus
-deafness
-blindness
-abnormally small head
-cognitive delay
potential consequences for developing baby when pregnant mother has genital herpes
-encephalitis
-enlarged spleen
-improper blood clotting
potential consequences for developing baby when pregnant mother has rubella (german measles)
-cognitive delay
-damage to eyes, ears and heat
potential consequences for developing baby when pregnant mother has syphilis
damage to CNS, teet and bones
whcih diseases pass from mother through the placenta to attack embryo or fetus directly
-cytomegalovirus
-rubella
-syphylis
-AIDS
what diseases attack babies at birth and how
-AIDS
-genital herpes
-virus is present in the lining of the birth cana, baby is infected as it passes through to be born
what drug can cause deficits in intelligence, attention, and motor skills in prenatal baby
aspirin
when pregnant women consume alcohol what are the 4 possible damages ot baby
-fetal alcohol spectrum disorder
-cognitive deficits
-heart damage
-retarted growth
what drug causes lower birth weight and decreased msucle tone to baby when rpegnant women consume too mcuh
caffeine
what drug causes low birth weight and less motor control to baby when pregneant women consumes
marijuana
what drug causes retarted growth and possible cognitive impairments to baby when pregnant women consume
nicotine
prior to pregnancy, what can smoking result in
-lowered rate of fertilit
-infertility
-implantation in the fallopian tube rather than uterus (ectopic pregnancy)
smoking during rpegnancy is related to what 5 complications
-problems with placenta and premature membrane rupture
-low birth weight
-peterm birth
-cleft palate
-sudden infant death syndrome
smoking after child is born can increase what 4 things
-child respiratory tract infection
-ear infection
-asthma
-sudden infant death synodrome
what are 5 problems caused by fetal acholohol spectrum disroder
-usually grow more slowly than normal
-heart problems
-intellectual delay
-poor social judgement
-limited motor skills, language and motor coordination
what are 4 physical characteristics of infant with fetal alcohol disorder
-small head
-thin upper lip
-short nose
-widely spaced eyes
what are the most common environmental teratognes
chemicals associated with industrial waste
potential consequences ond eveloping baby from led
cognitive delay
potential consequences ond eveloping baby from mercury
-retarted growth
-cognitive delay
-cerebral palsy
potential consequences ond eveloping baby from polychlorinated biphenyls
impaired memory and verbal skills
potential consequences ond eveloping baby from x-rays
-retarded growth
-leukemia
-cognitive delay
what were polychlorinated biphenyls used in
paints and electrical transformers
what environemtnal hazard substance has the most effect on cognitive and behavioural functioning of new borns
heavily chlorinated polychlorinated biphenyls
what is bisphenol A often used in and what can this cause for babies
plastics such as baby bottles and water bottles
-hormonal functioning
-linked to agression and other behaviorual problems in girls exposed during gestation
what are 4 thigns pregnant women should try to do when it comes to eating
-clean foods thoroughly to rid them of insecticides
-avoid convenience foods that contain additives
-stay away from air contaminated by household products (cleaners, fertilizers)
-try not to handle cats and kitty-litter boxes
why should pregnant women try not to handle cats
they can spread toxoplasmosis
-disease harmful to developing babies
what does the impact of teratogen depend on
genotype of the child
what was the difference between pregnant women and rats and rabbits they took thalidomide
-women: gave birth to children with deformed limbs
-rats: offspring had normal limbs
during the period of zygtoe exposure to teratogens usually results in what
spontaneous abortion of the fertilized egg
during the period of embryo exposure to teratogens usually results in what
major defects in body structure
what happens to babies when pregnant women contract rubella during the embryonic period
heart defects
during the period of fetus exposure to teratogens usually results in what
minor defects in body structures or cause body systems to function improperly
what happens to baby when pregnant women drink alcohol during fetal period
fetus develops fewer brain cells
what are 5 effects on baby when mom uses cocaine while pregnant
-impact on language skills
-neurobiological development
-cognitive functioning
-behavioural regualtion difficulties
-increased risk for mental health difficulties
when is the heart of baby most sensitive to teratogens
during first 2-3 of the embryonic peiord
what did pregnant women take the drug diethylstibestrol for and what effect did this have ont heir babies
to rpevent miscarriages
-appeared normal at birth
-as adults, girls more likely to ahve rare cancer of vagina and difficulty becoming pregnant
-sons can be less fertile and at risk for cancer of th etestes
when can ultrasounds be used to see baby
four or five weeks after concepition
when can you see gender of baby in ultrasound
16 to 20 weeks after conception
what is amniocentesis
medical procedure in which a sample of amniotic fluid is taken and tested for genetic disorders
what is chorionic villus sampling
medical procedure in which a sample of placental cells is taken and tested for genetic disordes
what method to see if baby has any disorders is often preferred
chorionic villus sampling
-can be done about 8 weeks after concpetion (2 motnhs earlier than amniocentesis)
what is one price of amniocentesis and chorionic villus sampling
miscarriages are slighlty mroe likely after
some cases of spina bifida have beend corrected in what way
fetal sugery in 7 to 9 month of pregnancy
-cut through abdominal wall and repair spinal cord and put baby back
how is endoscopic procedures perfored
through small cuts in the mothers abdmone, which a camera is insrterd and surgery is performed
out of open fetal surgery and endoscopic preocedures, which one is thought ot have fewer complications
open fetal surgery
how long do newborns sleep daily, and how could this cause problems for paretns
16-18h
-newborns sleep in naps, go through cycle of being awake for around an hour and sleep for 3
when do most babies begin to sleep through the night
around 3 or 4 months
what stage of sleep do newborns spend about half in and describe how babies act during it
REM
-rapid eye movement sleep
when does REM sleep become less frequent for newborns
as infant grows
-by 4 months only 40% in REM
-by 1 year REM drops to 25%
-average adult REm is 20%
in regular sleep (non-REM) how do newborns act
breathing, heart rate and brian activity are steady
-lie quietly without twwitching like in RE,
what do we know about REM and what do we believe about it
know
-its associated with increased production of proteins and stimulation of learning and memory in the brain
believe
-stimulates brain in some way that helps foster growth in the nervous system
in general, in 4 ways how is sleep important related to infants
-learning in infacncy due to its ability to facilitate neural maturation
-consolidate memory for events that happened during periods of wakefulness
-help infants process snesory stimuli and relationships in environment
-connected to immune function as well as other regulatory systems in body
what is sudden infant death syndrome
crib death
-a healthy baby suddenly and unexpectedly dies, for no apparent reason
what is the most common cause of postneonatal death
sudden infant death syndrome
what are 5 contributing factors to sudden infant death syndrome
-born prematurely
-born with low birth weight
-if parents smoke cigarettes
-when baby sleeps on stomach
-winter, when baby become overheated from too many blankets
what are 5 signs of postpartum depression
-feelings of low self-worth
-disturbed sleep
-poor appetite
-apathy
-might not touch, cuddle or talk to their babies much
what may reduce risk of sudden infant death syndrome
sleeping with a pacifier
what biology thing contributes to placing women at risk postpartum depression
high levels of hormones during later phases of pregnancy
if postpartum depression lasts for months and month, what effect does this have on the baby
they are more likely to become depressed themselves and are also at risk for other behavioural problems
when does labour begin
when the muscles of the uterus start to contract, forcing amniotic fluid against the opening at the bottom of the uterus
wave like motion of the amniotic fluid with each contraction causes what
the cervix to enlarge gradually
what are the contractions like in early and end phase of stage 1
-weak and spaced irregularly
-stronger and occur at regular interval
by the end of stage 1, what size is the cervix
7-8 cm in diameter
women report what stage to be the most painful part about labour and why
transition phase of stage 1
-contractions are intense and sometimes occur without interruption
at the end of the transition stage of labour, what size is the cervix
10cm
how long does stage 1 of labout typically last
12-24h
when does the second satge of labour begin
when the cervix is fully dialted
what is breech presentation
when baby comes out feet first or bottom firts
-small percentage
what have some researchers found about babies born as breech presentation
have normal neuromotor development
-may actually experience a roomier environment in utero than fetuses developing head down
what marks the end of the second stage of labour
birth of baby
what is the third stage of labour and how long does it last
afterbirt, placenta is expelles from the uterus
-10 -15 min
what is a doula
person who provides professional support and education about birth but does not provide medical intervention
why are natural methods of dealing with pain during birth emphasized over medication
when anaesthetized cant use abdomnial msucles to help psuh the baby through birth canal
what are the 3 ways childbirth classes teach to counteract labour pain without drugs
-deep breathing
-visual imagery
-involve a supportive coach
who experiences the most amount of birth related fear
women over 40
what is anoxia
complete lack of oxygen
what can cause anoxia in babies in uterus
sometimes during labour and delivery because umbilical cord is pinched or squeezed shut, cutting off flow of blood
or
placenta abruptionL occurs when placenta beocmes detached from wall of uterus, severing connection to mothers blood supply
what are 2 thigns anoxia can lead to in babies
-cognitive delay
-death
what is reduced oxygen supply called
hypoxia
when are infants normally born and when are premautre infants bron
normal: 38 weeks
not: less than 38 weeks
out of premature and low weigh t, which is the less serious one
prematurity
at what age do premature ifnants start to develop normally
by age 2 oor 3
what is one of the greatest challneges for premature infants
damage to or underdevelopment of the cerebellum of rbain
-can result in later deficits in aspects of cognition, behaviour, and socializatoin
small for date babies are msot often born to women who what
smoke cigarettes or drink alcohol frequently during pregnancy or who not eat enough nutritious foods
at what weight do babies usually not survive and what happens if they do
1500
-delayed in cognitive and motor development
babies low birth weight are typically how many grams
2500
in the apgar score, what are the 5 vital signs health professionals look for
breathing, heartbeat. muscle tone, presence of reeflexes, skin tone
what do the scores mean in the apgar score
7 or more - good physical condiiton
4 to 6 - need special attentiona nd care
3 or less - life threatenening situation
what is the purpose of the neonatal behavioural assessment
evaluates broad range of newborn abilities and behaviours that the infant needs to adjust to life outside the uterus
newborns spend most of their day alternating between whay 4 stages
-alert inactivity (calm and eyes open)
-waking activity (eyes open unfocused)
-crying
-sleeping
describe a basic baby cry
starts softly then gradually becomes more intensen
babies basic cry usually when
when hungry or tired
describe a mad cry
more intense verios of basic cry
descibe a pain cry
begins with a sudden long burst of crying, followed by a long pause and gasping
