Flashcards in 7.2 Foetal Growth And Development Deck (58):
When is pregnancy calculated from?
The date of last menstrual period
What pattern of growth characterises the embryonic period?
Intense activity - organogenetic period
Absolute growth is very small (except placenta)
What happens to growth in the foetal period?
Growth and weight gain accelerate
During which periods does CRL rapidly increase?
When is weight gain at its fastest (of foetus)?
Mid and late foetal periods
What sort of growth occurs in the embryo?
Intense morphogenesis and differentiation
Not much weight gain
Significant placental growth
What sort of growth happens in the early foetus?
What sort of growth occurs in the late foetus?
Why is the CRL less useful in the foetal period?
Body proportions change dramatically
What are the body proportions at week 9?
Head is approximately half CRL
What happens to the body proportions after week 9?
Body length and lower limb growth accelerates
What are 3 sources of ante-natal assessment of foetal wellbeing?
Mother -> Foetal movements
Measurements of uterine expansion
How is uterine expansion measured?
What must be taken into consideration when using symphysis-fundal height?
It is not just the foetus that is occupying the space
There is amniotic fluid too
When would a first time mother feel foetal movements?
What can the USS be used to detect early in pregnancy?
Rule out ectopic
Number of foetuses
Assess foetal growth
Why is the USS done at 20 weeks?
Structures are developed
Structures are large enough to see
What is the 20 week scan sometimes known as?
What methods can be used to estimate foetal age?
When is CRL measured?
Between 7 and 13 weeks
What is a T1 scan used for?
Estimate due date
Why is CRL not used later in pregnancy?
Less strong correlation between crown and rump
What is the biparietal diameter?
The distance between the parietal bones of the foetal skull
When in pregnancy is is biparietal diameter used?
T2 and 3
What is AC & FL?
Abdominal circumference and femur length
What is AC&FL used for?
Dating and growth monitoring (when used in combination with BPD)
What is an average birth weight?
What does a birth weight of less than 2500g suggest?
What birth weight is classified as macrosomia?
What could be a cause of macrosomia?
What part of the lungs develops in the embryonic period?
What occurs to the lungs in the foetal period?
What is the lung derived from?
Out-pocket of foregut
Which lung development stage occurs from weeks 8-16?
What developmental stage occurs in the lungs at weeks 16-26?
What developmental stage occurs in the lungs from weeks 26-term?
Terminal sac stage
What occurs during the pseudoglandular stage of lung development?
Duct system begins to form within the bronchopulmonary segments
What occurs during the canalicular stage?
Formation of respiratory bronchioles
What occurs during the terminal sac stage?
Terminal sacs bud from respiratory bronchioles
Differentiation of type 1 and 2 pneumocytes
Where does gas exchange occur in a foetus?
At the placenta
How do the lungs prepare to work at birth?
Breathing movements to condition the respiratory muscles
Fluid filled for normal lung development
When is viability possible?
When the lungs have entered the terminal sac stage
Why does respiratory distress syndrome often affect premature babies?
Insufficient surfactant production
What treatment can be given is preterm delivery is unavoidable?
Glucocorticoid treatment of mother to increase surfactant production in foetus
What is the definitive foetal HR and when is it achieved?
At 15 weeks
When doesfoetal kidney function begin?
What is a major contributor to amniotic fluid?
Why is foetal kidney function not necessary for survival in utero?
Renal function managed by the placenta
What may be seen if there is decreased foetal kidney function?
What is oligohydramios and what can it be caused by?
Too little AF
Foetal renal impairment
What is polyhydramnios and what is it caused by?
Too much AF
Foetal abnormality eg inability to swallow
What may lead to a foetus being unable to swallow?
Tracheoesphageal septum in wrong place
CNS defect meaning foetus is unable to coordinate swallowing
Which system is the first to begin and last to finish developing?
What system begins to develop in the 4th month?
Corticospinal tracts which are required for voluntary movements
At which week will movement begin to be seen in the foetus?
What is quickening?
Maternal awareness of foetal movements from 17 weeks onwards
Describe the clinical advantage of quickening
Low cost, simple method of ante-partum foetal surveillance