Adaptation at birth

Question 1

What is the placental function?

Answer 1

Foetal homeostasis
Gas exchange
Nutrient transport to foetus
Waste product transport from foetus
Acid base balance
Hormone production; baby ready for labour
Transport of IgG

Question 2

What is the role of the foetal liver and kidney?

Answer 2

Liver; albumin, clotting factor, RBC

Kidney; excretes urine, contributes to amniotic fluid

Question 3

What is the role of the foetal endocrine system?

Answer 3

Thyroid hormones
Corticosteroids 
Mineralocorticoids 
PTH 
Insulin

Question 4

What are the 3 shunts present in the foetal circulation?

Answer 4

Ductus venosus
Foramen ovale
Ductus arteriosus

Question 5

What % of the foetal circulation goes to the lungs?

Answer 5

7%

Question 6

What occurs in the 3rd trimester to prepare the foetus for birth?

Answer 6

Surfactant production
Accumulation of glycogen at liver, muscle and heart
Accumulation of brown fat; scapulae and internal organs
Accumulation of subcutaneous fat
Swallowing of amniotic fluid

Question 7

What produces surfactant?

Answer 7

Type 2 pneumocytes

Question 8

What is the role of surfactant?

Answer 8

Reduced surface tension

Question 9

How much fluid is present in foetal lungs?

Answer 9

100ml

Question 10

What is the benefit of vaginal delivery in terms of lung fluid?

Answer 10

Squeezes out 30%, this can be a reason for transient tachypnoea of the newborn in c/s babies (no squeezing)

Question 11

How does the circulation transition as the baby is born?

Answer 11

Pulmonary vascular resistance drops 
Systemic vascular resistance rises
Oxygen tension rises
Circulating prostaglandins drop
Duct constricts
Foramen ovale closess

Question 12

How does the arterial pO2 change as the baby is born?

Answer 12

Rises from 2-3.5 to 9-13 kPa

Question 13

What factors allows for the duct closure in babies post birth?

Answer 13

Decreased flow due to decreased pulmonary vascular resistance
Increased pO2 (oxygen sensitive muscular layer)
Decreased circulating PGE2 due to increased lung metabolism
Shut becomes bidirectional then left-right

Question 14

When is the physiological and anatomical closure of the ductus venous?

Answer 14

Physiological; few hours

Anatomic; 7-10 days

Question 15

What is the fate of the foramen ovale?

Answer 15

Closes or persists as PFO (10%)

Question 16

What is the fate of the ductus arteriosus?

Answer 16

Becomes ligamentum arteriosus

Question 17

What is the fate of the ductus venosus?

Answer 17

Becomes ligamentum teres

Question 18

What can result in failure of cardiopulmonary adaptation?

Answer 18

Asphxia; hypoxia/ acidosis 
Prematurity 
Sepsis
Hypoxia - meconium aspiration 
Cold stress 
Chorioamnionitis 
Hypothermia

Question 19

What is PPHN?

Answer 19

Lung vascular resistance fails to fall
Shunts remain; right to left at PFO, right to left at PDA
High pressure in the pulmonary vascular system

Question 20

What is a good test to assess PPHN?

Answer 20

Pre and post ductal o2 sats

Question 21

How is PPHN managed?

Answer 21

Ventilation 
Oxygen 
NO - vasodilator 
Sedation 
Inotropes 
ECLS/ ECMO

Question 22

What adaptations occur within the first couple of hours?

Answer 22

Thermoregulation
Glucose homeostasis
Nutrition

Question 23

Why is thermoregulation a problem for babies?

Answer 23

Large surface area

Wet when born

Question 24

What are the 4 methods of heat loss?

Answer 24

Radiation
Convection
Conduction
Evaporation

Question 25

Can babies shiver?

Answer 25

No; therefore main source of heat is non shivering thermogenesis

Question 26

How do babies produce heat?

Answer 26

Breakdown of stored brown adipose tissue in response to catecholamines

Question 27

Can babies breakdown brown adipose tissue in the first 12 hours of life?

Answer 27

No; peripheral vasoconstriction occurs | Newborns need help with maintaining temp; between 36.5-37.5

Question 28

Who do small for dates/ preterms need help maintaining temp?

Answer 28

Low stores of brown fat Little subcutaneous fat Larger surface area:vol

Question 29

How can hypothermia be prevented in newborns?

Answer 29

``` Dry Hat Skin to skin Blanket/ clothes Heated mattress Incubator ```

Question 30

How does glucose homeostasis change in the first couple hours of life?

Answer 30

Interruption of glucose supply from placenta Very little oral intake of milk Drop in insulin, increase in glycogen Mobilisation of hepatic glycogen stores for gluconeogenesis Ability to use ketones for brain

Question 31

What can predispose to hypoglycemia in a newborn?

Answer 31

Increased demands; unwell, hypothermia Low glycogen stores; small/ prem Inappropriate insulin/ glucagon ratio; maternal diabetes, hyperinsulinism Beta blockers

Question 32

How can hypoglycemia be avoided in newborns?

Answer 32

Identify those at risk Feed effectively Keep warm Monitor

Question 33

What are the different forms of breastmilk?

Answer 33

Colostrum Foremilk Hindmilk

Question 34

What is a normal weight loss in the first week following birth?

Answer 34

10%

Question 35

What can occur if more than 10% of weight is lost?

Answer 35

Hypernatremic

Question 36

What chemical will result in the changes of foetal Hb?

Answer 36

2,3 BPG | Shifts curve to the right

Question 37

Where will haematopoiesis move to/from after birth?

Answer 37

From liver to bone marrow

Question 38

Why will there be a physiological anaemia at 8-10 weeks post birth?

Answer 38

Adult Hb is synthesised more slowly than foetal Hb is broken down

Question 39

What type of bilirubin results in physiological jaundice?

Answer 39

Unconjugated as conjugating pathways are immature

Question 40

What are the 2 methods of treating jaundice in babies?

Answer 40

Phototherapy | Exchange transfusion

Question 41

What is a bad side effect of prolonged and high jaundice in a baby?

Answer 41

Kernicterus; bilirubin deposits in basal ganglia resulting in athetoid CP and deafness

Question 42

What babies are at risk to maladaptation?

Answer 42

``` Hypoxia/ asphyxia during delivery SGA or LFD Prematures Maternal illness Ill babies; sepsis or congenital anomalies ```