9. foetal growth and development 3 (workbook) Flashcards
which is the fastest developing organ in the foetus and infant?
brain
how much of the body weight does the brain account for?
12% at birth
falling to around 2% in adults
what are the important changes that occur during foetal period to the brain structurally and functionally?
- cerebral hemisphere becomes largest part of brain
- histological differentiation of cortex in cerebrum and cerebellum
- formation and myelination of nuclei and tracts
- relative growth of the spinal cord and vetebral column
what happens to allow for cerebral hemisphere to become largest part of the brain?
gyri and sulci form after 5 months as the brain grows faster than the head
when do hearing and taste mature?
before vision
when are the organ of corti and retina developed?
organ of corti (inner ear): at 5 months
retina: immature at birth
when are foetal movements seen and felt?
seen at 8 weeks (ultrasound)
felt at 17 weeks
what are the 4 features of foetal development of clinical importance?
- foetal movements (quickening)
- viability
- SENSory awareness e.g. pain, sound
- maternal / neonatal nutrition and cortical development
what are foetal movements known as?
quickening
what is viability?
is the brain sufficiently mature to control body functions e.g. breathing
what is foetal waste excreted ultimately by?
the placenta
what us the functional foetal kidney?
metanephros
what happens to the metanephros at around 10 weeks?
ascent is complete and function begins
kidneys have lobulated form, until 4-5 years
what is present at 10 weeks of the kidneys?
glomeruli and some tubules
what is present at 23 weeks of the kidneys?
renal pelvis
renal calyces
what happens by 8 months to the kidneys?
histological differentiation of cortex and medulla is almost complete
where does the bladder lie in foetus and infants?
in abdominal cavity
where does urine entering the bladder empty into in foetus?
urine enters the bladder and is emptied into the amniotic fluid, to be swallowed by the foetus
what is the rate at which foetal bladder empties?
every 40-60mins
can be seen on ultrasound scans
what is the rate of foetal bladder emptying used for?
used clinically to assess foetal urinary function
what is the foetal circulation adapted to do?
to bring oxygenated blood from the placenta to the foetus via umbilical vessels
what do the foetal lungs receive in terms of CVS?
the foetal lungs receive only the blood needed to sustain their own growth and development
what changes at birth to the CVS?
rapid and profound changes take place in the circulation at birth, related to the onset of air breathing
how can foetal growth and development be assessed?
via a range of tests that monitor changes in anatomical and physiological parameters
what are the tests that can be done to assess foetal growth and development?
- ultrasound
- doppler ultrasound
- non-stress test (NST)
- biophysical profiles (BPP)
- vibroacoustic stimulation
- contraction stress tests
- foetal movements kick-chart
what do non-stress tests (NST) monitor?
monitors heart rate changes associated with foetal movement
what do vibroacoustic stimulations monitor?
foetal heart rate change
what do biophysical profiles (BPP) consist of>
5 variables to be measured
what do the tests done in utero indicate?
foetal organ system development and functionality
how does foetal weight change during the embryonic and foetal period?
slow weight gain in embryonic period
increases rapidly in foetal period
initially, what accounts for most of the weight gain in the foetal period?
protein
when does foetal weight gain change?
after 28 weeks, foetal adipose tissue is laid down in subcutaneous and abdominal stores
(from protein prior to 28 weeks of foetal period)
when is a foetus regarded as having ‘growth restriction’?
if his / her estimated weight is below the 10th percentile for his gestational age
depending on the cause a foetus with growth restriction may be compromised in what?
the uterine environment and require closer monitoring in order to allow the continuation of the pregnancy to term
what are the 2 main types of growth restriction?
- symmetrical
2. asymmetrical
what is symmetrical growth restriction?
growth restriction is generalised and proportional
what is asymmetrical growth restriction?
abdominal growth lags
there is relative sparing of head growth
when does asymmetrical growth restriction tend to occur?
in the last part of pregnancy when maternal, foetal or utero-placental factors cause some deprivation of nutritional and oxygen supply to the foetus
