Small Babies

Question 1

Embryonic period is characterised by

Answer 1

Intense organogenetic activity
Growth is very little except for the placenta

Question 2

When is there an acceleration in growth of the foetus

Answer 2

After 8 weeks

Leads to exponential increase in weight of foetus

Question 3

What is an accurate measure of assessing the age of the embryo

Answer 3

Crown rump length CRL

At 9 weeks = 5cm

At 38 weeks = 36cm

Question 4

Weight gain in the early foetal stage is due to _____

Answer 4

Deposition of new protein

Question 5

Weight gain in the late foetus stage is due to

Answer 5

Deposition of adipose tissue

Question 6

How do body proportions change as the foetus grows

Answer 6

At week 9 the head and neck account for half of the length of the foetus

As foetus grows (limbs and trunk) = more proportionate

Question 7

What is main mechanism of growth in the first 20 weeks

Answer 7

Hyperplasia

Question 8

What is the mechanism of growth in 20-28 weeks

Answer 8

Hyperplasia and hypertrophy

Question 9

What is the mechanism of growth after 28 weeks

Answer 9

Hypertrophy

Question 10

Growth restriction can be……

Answer 10

Symmetrical = proportional growth of the head and body

Asymmetrical = head is spared and body is disproportionately smaller

Question 11

Hormones that are essential for foetal growth

Answer 11

Insulin

IGFII = nutrient independent in dominates in T1

IGF I - nutrient dependent and dominates in T2 and T3

Leptin = important in placental formation

Epidermal growth factor EGF and TGF alpha (transforming growth factor)

Question 12

Which hormone is nutrient independent and what trimester does it dominate

Answer 12

Insulin like growth hormone I

Trimester 1

Question 13

What is macrosomia

Answer 13

Baby weight greater than 4.5kg

Indicative of gestational diabetes

Question 14

What is considered a healthy weight for a newborn

Answer 14

3.5kg

Question 15

Less than ________kg is suggestive of foetal growth restriction

Answer 15

2.5kg

Question 16

Why can babies have a low birth weight

Answer 16

• if are born prematurely
• smaller mothers give birth to smaller babies
• if have suffered growth restriction

Question 17

There is a greater risk of ________________ & ________________ in IUGR babies

Answer 17

Mortality
Morbidity

Question 18

What things can be looked at in an antenatal assessment of foetal wellbeing

Answer 18

• mother ( fetal movements or not)
• biochemical tests
• regular measurement of uterine expansion by measuring symphysis-fundal height
• ultrasound scan

Question 19

What are we trying to detect in a biochemical test

Answer 19

• hCG maintains corpus luteum
• HPL (human placental lactogen) regulates metabolism of macromolecules
• alpha fetoprotein - transfer of heavy metal ions in to the foetal bloodstream

Question 20

What are the negatives of biochemical tests

Answer 20

Expensive

Poor positive predictive value

Question 21

A 12 week scan is carried out for what reasons

Answer 21

Rule out ectopic pregnancies
Number of foetuses?

Question 22

A 20 week scan is carried out for what reasons

Answer 22

Assess foetal growth and any anomalies

Question 23

What is used between 7-13 weeks

Answer 23

Crown rump length

To date the pregnancy, estimate EDD

Question 24

Head and abdominal circumference with femur length is measured at ______

Answer 24

20 weeks

Question 25

What is a Doppler ultrasound used for

Answer 25

Assessment of wave pattern of blood through umbilical artery Used in assessment of IUGR at risk babies

Question 26

What is the Normal results of a Doppler ultrasound

Answer 26

Increase in diastolic velocity There will be a decrease in the indices measured such as PSV, MDV and TAPV PSV = peak systolic velocity MDV = mean diastolic velocity TAPV = time averaged peak velocity

Question 27

Worsening umbilical artery Doppler shows

Answer 27

1) increased systolic: diastolic ratio with no rise in diastolic flow 2) absent end diastolic flow in the umbilical artery 3) reverse diastolic flow - there is reflux through the artery

Question 28

What are features are indicative of early foetal hypoxia

Answer 28

Raised umbilical artery pulsatility Absent end diastolic flow

Question 29

What other artery can a Doppler look at

Answer 29

Uterine artery

Question 30

What is the pathogenesis of IUGR

Answer 30

Normally to establish a high flow, low resistance system remodelling of the spiral arteries is required. Remodelling is carried out by invading trophoblasts which migrate into the arterioles and replace the endothelial cells with trophoblast cells Reduction/loss of vascular smooth muscle in spiral arteries so cannot spasm and create high flow, low resistance flow that is needed

Question 31

What is the decidual reaction

Answer 31

Endometrium becomes the decidua Reaction creates Goldilocks zone - enough invasion to allow permissive circulation but not too much that it invades the myometrium as well

Question 32

A sub-optimal decidual reaction can lead to what kind of adverse effects in pregnancy

Answer 32

Placental insufficiency Pre-eclampsia

Question 33

What are foetal risk factors for IUGR

Answer 33

Genetics: chromosomal abnormalities or single gene disorders Epigenetics = methylation disorder Infections = TORCH

Question 34

What infections can increase a foetuses risk for IUGR

Answer 34

TORCH Toxoplasmosis Others varicella, syphilis and parvovirus Rubella Cytomegalovirus HIV

Question 35

What maternal risk factors are there for IUGR

Answer 35

Pre-existing medical conditions such as chronic hypertension, renal disease and CVD Drug exposure = smoking and alcohol

Question 36

Which placental factors pose a risk for IUGR

Answer 36

Placental infarction Placental abruption = placenta torn away from decidua Placental insufficiency = hypertensive disorders and maternal diabetes

Question 37

Why does timing of the insult matter

Answer 37

Early phase insult = hyperplasia phase in which foetus is symmetrically affected in terms of IUGR Late phase insult = hypertrophy phase where foetus is asymmetrically affected

Question 38

How is the head sparing effect achieved

Answer 38

Decreased glycogen deposition in the liver Decreased adipose tissue deposition in the system = decreased abdominal size in proportion to body

Question 39

What is the barker hypothesis

Answer 39

Foetal programming during development leading to adult metabolic disorders Obesity, diabetes, insulin insensitivity, hypertension, hyperlipidemia and CHD

Question 40

A sub-optimal in utero environment may impact adult health how

Answer 40

Pulmonary insufficiency Hypertension Renal insufficiency Insulin insufficiency Altered glucose/lipid metabolism Immune deficiency Neurodegenerative and cognitive diseases Obesity