7.2 Foetal Growth And Development

Question 1

When is pregnancy calculated from?

Answer 1

The date of last menstrual period

Question 2

What pattern of growth characterises the embryonic period?

Answer 2

Intense activity - organogenetic period

Absolute growth is very small (except placenta)

Question 3

What happens to growth in the foetal period?

Answer 3

Growth and weight gain accelerate

Question 4

During which periods does CRL rapidly increase?

Answer 4

Pre-embryonic
Embryonic
Early foetal

Question 5

When is weight gain at its fastest (of foetus)?

Answer 5

Mid and late foetal periods

Question 6

What sort of growth occurs in the embryo?

Answer 6

Intense morphogenesis and differentiation
Not much weight gain
Significant placental growth

Question 7

What sort of growth happens in the early foetus?

Answer 7

Protein deposition

Question 8

What sort of growth occurs in the late foetus?

Answer 8

Adipose deposition

Question 9

Why is the CRL less useful in the foetal period?

Answer 9

Body proportions change dramatically

Question 10

What are the body proportions at week 9?

Answer 10

Head is approximately half CRL

Question 11

What happens to the body proportions after week 9?

Answer 11

Body length and lower limb growth accelerates

Question 12

What are 3 sources of ante-natal assessment of foetal wellbeing?

Answer 12

Mother -> Foetal movements
Measurements of uterine expansion
Ultrasound scan

Question 13

How is uterine expansion measured?

Answer 13

Symphysis-fundal height

Question 14

What must be taken into consideration when using symphysis-fundal height?

Answer 14

It is not just the foetus that is occupying the space

There is amniotic fluid too

Question 15

When would a first time mother feel foetal movements?

Answer 15

20 weeks

Question 16

What can the USS be used to detect early in pregnancy?

Answer 16

Calculate age 
Rule out ectopic
Number of foetuses
Assess foetal growth 
Anomalies

Question 17

Why is the USS done at 20 weeks?

Answer 17

Structures are developed

Structures are large enough to see

Question 18

What is the 20 week scan sometimes known as?

Answer 18

Anomaly scan

Question 19

What methods can be used to estimate foetal age?

Answer 19

LMP

Development criteria

Question 20

When is CRL measured?

Answer 20

Between 7 and 13 weeks

Question 21

What is a T1 scan used for?

Answer 21

Date pregnancy 
Estimate due date 
Check location 
Number 
Viability

Question 22

Why is CRL not used later in pregnancy?

Answer 22

Less strong correlation between crown and rump

Question 23

What is the biparietal diameter?

Answer 23

The distance between the parietal bones of the foetal skull

Question 24

When in pregnancy is is biparietal diameter used?

Answer 24

T2 and 3

Question 25

What is AC & FL?

Answer 25

Abdominal circumference and femur length

Question 26

What is AC&FL used for?

Answer 26

Anomaly detection Dating and growth monitoring (when used in combination with BPD)

Question 27

What is an average birth weight?

Answer 27

3500g

Question 28

What does a birth weight of less than 2500g suggest?

Answer 28

Growth restriction

Question 29

What birth weight is classified as macrosomia?

Answer 29

>4500g

Question 30

What could be a cause of macrosomia?

Answer 30

Maternal diabetes

Question 31

What part of the lungs develops in the embryonic period?

Answer 31

Bronchopulmonary tree

Question 32

What occurs to the lungs in the foetal period?

Answer 32

Functional specialisation

Question 33

What is the lung derived from?

Answer 33

Out-pocket of foregut

Question 34

Which lung development stage occurs from weeks 8-16?

Answer 34

Pseudoglandular stage

Question 35

What developmental stage occurs in the lungs at weeks 16-26?

Answer 35

Canalicular stage

Question 36

What developmental stage occurs in the lungs from weeks 26-term?

Answer 36

Terminal sac stage

Question 37

What occurs during the pseudoglandular stage of lung development?

Answer 37

Duct system begins to form within the bronchopulmonary segments (Bronchioles)

Question 38

What occurs during the canalicular stage?

Answer 38

Formation of respiratory bronchioles

Question 39

What occurs during the terminal sac stage?

Answer 39

Terminal sacs bud from respiratory bronchioles | Differentiation of type 1 and 2 pneumocytes

Question 40

Where does gas exchange occur in a foetus?

Answer 40

At the placenta

Question 41

How do the lungs prepare to work at birth?

Answer 41

Breathing movements to condition the respiratory muscles | Fluid filled for normal lung development

Question 42

When is viability possible?

Answer 42

When the lungs have entered the terminal sac stage | >24 weeks

Question 43

Why does respiratory distress syndrome often affect premature babies?

Answer 43

Insufficient surfactant production

Question 44

What treatment can be given is preterm delivery is unavoidable?

Answer 44

Glucocorticoid treatment of mother to increase surfactant production in foetus

Question 45

What is the definitive foetal HR and when is it achieved?

Answer 45

110-160 bpm | At 15 weeks

Question 46

When doesfoetal kidney function begin?

Answer 46

Week 10

Question 47

What is a major contributor to amniotic fluid?

Answer 47

Foetal urine

Question 48

Why is foetal kidney function not necessary for survival in utero?

Answer 48

Renal function managed by the placenta

Question 49

What may be seen if there is decreased foetal kidney function?

Answer 49

Oligohydramnios

Question 50

What is oligohydramios and what can it be caused by?

Answer 50

Too little AF Placental insufficiency Foetal renal impairment

Question 51

What is polyhydramnios and what is it caused by?

Answer 51

Too much AF | Foetal abnormality eg inability to swallow

Question 52

What may lead to a foetus being unable to swallow?

Answer 52

Tracheoesphageal septum in wrong place | CNS defect meaning foetus is unable to coordinate swallowing

Question 53

Which system is the first to begin and last to finish developing?

Answer 53

Nervous system

Question 54

What system begins to develop in the 4th month?

Answer 54

Corticospinal tracts which are required for voluntary movements

Question 55

At which week will movement begin to be seen in the foetus?

Answer 55

8th week

Question 56

What is quickening?

Answer 56

Maternal awareness of foetal movements from 17 weeks onwards

Question 57

Describe the clinical advantage of quickening

Answer 57

Low cost, simple method of ante-partum foetal surveillance

Question 58

When does myelination of the brain begin?

Answer 58

Week 36