Fetal Development and Adaptation to Extra-Uterine Life

Question 1

```Before birth the baby “breathes”

~~~

How does the lung develop in late pregnancy?

Answer 1

During REM the diaphragm distends stimulating their growth. Surfactant is produced reducing surface tension stimulated by cortisol

Surfactant needed for first breath

Question 2

Respiratory distress syndrome in premies are given this

What can be given to premature babies to cause lung development?

Answer 2

Glucorticoids

Question 3

When do functioning lungs really develop?

Answer 3

35ish weeks

Question 4

What happens to liver glycogen when cortisol rises?

Answer 4

It goes down so the baby is saving some for energy

Question 5

What do fetal circulation - shunts do?

Answer 5

Incorporates the placenta into fetal circulation and insures appropraite delivary of oxygenated blood and nutrients

Question 6

What the umbilical arteries take blood to? and what does the vein do?

Answer 6

The body to the placenta and the vein takes deoxygenated blood from placenta to body

Question 7

There is 3 of these

What are the shunts?

Answer 7

Ductus Venosus
Ductus Ateriosus
Foramen Ovale

Question 8

What does the Ductus Venosus do?

Answer 8

Shunts oxygenated blood from placenta away from the semifunctioning liver and to the heart.

Shunt 1

Question 9

What does the Ductus Ateriosus do?

Answer 9

Connects the aorta with the pulmonary artery shunting blood away from lungs and to the aorta

Shunt 3

Question 10

What does the Foramen Ovale do?

Answer 10

allows oxygenated blood in the right atrium to reach the left atrium

This can cause a hole in the heart and is split into 2 streams.

Shunt 2

Question 11

How would you get back to our circulation?

The adult human circulation instead of the fetal circulation

Answer 11

Shut the shunts

Question 12

Protaglandin E2, cortisol, BP

How is the fetal cardiovascular system matured?

Answer 12

Prostaglandin E2 maintina patent ductus arteriosus

Cortisol increases cardiac output and peripheral resistance

Increase in blood pressure

Question 13

what is the first thing which happens as the fetus transitions to adult circulation?

Answer 13

When born the baby takes a deep breath decreasing the vascular resistance letting blood into lung easily. You also lose the umbilical circulaton and the three shunts close.

Question 14

R and L side of heart, DA shunt involvement/ stimulation

What happens second in the transition from fetal circulation to adult circulation?

Answer 14

Drop in pressure of R side of heart and a rise on the L side of heart creating a transient reversal of flow through the Ductus Arteriole (DA) and the high pO2 stimulates the DA to contract

Question 15

What is the third thing that happens when changing from fetal to adult circulation?

Answer 15

DA constriction inhibited by low pO2 and high PGE2

Foreman Olvale (FO) valve with reversal pressure in the atria pushes against wall separating both sides of the heart

Question 16

What adult diseases can come from fetal programming and how is this caused?

Answer 16

Can lead to chronic diseases in childhood for example, raised stress response, CVD’s, obesity and diabetes.

Can be caused from interuterine insult e.g. hypocia, nutrition, prenatal stress, glucorticoids and smking

Question 17

What is being researched in terms of resistance in utero?

Answer 17

Insulin, leptin and glucorticoids

Question 18

Can some stress be good for babies?

Answer 18

Yes - such as stress from a normal birth rather than a caesarean section

Question 19

What is the barker hypothesis?

Answer 19

low birth weight can increase the risk of coronary heart disease

Question 20

What did the Dutch famine show?

What happened to fetus’ in early pregnancy vs mid pregnancy and both

Answer 20

Fetuses in early pregnancy during the dutch famine where more likely to get coronary heart disease, increased obesity, altered clotting, atherogenic lipid profile. Increased amount of people reporting poor health

If you were mid gestation the baby would be more likely to have obstructive airway disease

And in any stage decreased glucose tolerance and improved fertility was seen