Foetal Growth And Development Flashcards
Which system is the last to develop ?
Respiratory
What is the aim of the foetal period ?
Growth and maturation of structures that where made in embryonic period
Prepare for transition to life after birth
When is the foetal period ?
Week 9 to birth
Which growth happens first first and rapidly and which one is slow ?
Crown rump length first and rapid
Weight gain slow at first and increases in foetal period
How can we assess the foetal well-being and development at 20 weeks (3) ?
- Fetal movements felt by mother
- Uterine expansion : symphysis-fundal height should be around umbilicus
- Ultra-sound
Why is ultrasound offered at 20 weeks , what are the measurement used for later in pregnancy ?
- Safe
- Can be used to calculate age and predict delivery date
- Rule out ectopic pregnancy
- At 20 weeks , structures big enough to see : can see abnormalities and assess Fetal growth
Later used to monitor growth
How can we estimate the Fetal age ?
- Last menstruation period
- compare to criteria of different stages (eg crown rump length…)
Which measurement are used to assess age and growth of foetus ?
- Biparietal diameter (distance between parietal bones : in 2nd and 3rd trimester)
- Abdominal circumference and femur length
What are the classification of birth weights ?
Normal : 3500g
Growth restriction : Below 2500g
Macrosomia : Above 4500g
What can influence birth weight ?
- Dating of foetus (premature)
- Constitution (naturally small)
- Growth restriction
- Maternal diabetes …
How does the respiratory system develop ?
From the foregut
Forms the respiratory diverticulum which is then separated by the tracheoesophageal septum
By the end of the embryonic period , how developed is the respiratory system ?
Only bronchopulmonary tree present
Describe the 3 stages of foetal development of the respiratory system
- Pseudoglandular stage (weeks 8-16) : creation of bronchioles
- Canalicular stage (week 16-26) : Formation of respiratory bronchioles
- Terminal sac stage (week 26 to term) : Creation of alveoli + differentiation of Type I and II pneumocytes.
What do the lungs do during trimester 2 and 3 ? Why ?
Breathing movements start around week 11 to condition respiratory musculature and fill with fluid that contains factors for pneumocytes differentiation
What is the threshold for viability , why ?
Over 24 weeks
Before that , lungs under developed (not in terminal sac stage ) and no surfactant production (respiratory distress syndrome)
What is respiratory distress syndrome of the new born ?
Affects infants born pre-maturely
Insufficient surfactant production
If pre-term delivery is unavoidable , what can be done to prevent respiratory distress syndrome ?
Glucocorticoid to mother to increase surfactant production in foetus
What is the average fetal HR and when can is the definitive HR achieved ?
15 weeks
120-160bpm
The BioPhysical Profile is used to assess 5 parameters of fetal-wellbeing , what are they and what system do they assess?
Fetal movement : CNS
Fetal breathing movement : lungs development and CNS
Fetal tone : MSK
Amniotic fluid volume : Renal and GI
Fetal heart rate response to movement : ANS and CVS
At which week is the kidney functional ?
Week 10
How is the renal function of the foetus managed during pregnancy ?
Managed by mother via placenta
Why is amniotic fluid a good indicator of Fetal development ?
Most of amniotic fluid consists of Fetal urine
Polyhydramnios or oligohydramnios are indicator of abnormalities in GI or Renal development of the foetus
Other than foetal renal impairment , what can cause Oligohydramnios ?
Placental insufficiency
When do corticospinal tracts develop and what do they do ?
Begin in the 4th month
For coordinated voluntary movements
When does myelinated not of the brain begins ?
9th month but incomplete at birth
When do first movements happen ?
8th week
