Adaptations at Birth

Question 1

what are the functions of the placenta (6)

Answer 1

foetal homeostasis, gas exchange, nutrient and waste transport, IgG transport, acid-base balance, hormone production (oestradiol)

Question 2

the foetal heart pumps deoxygenated blood to placenta via ___ ____

Answer 2

umbilical arteries

Question 3

placenta returns oxygenated blood to the foetus via ____ ___

Answer 3

umbilical veins

Question 4

what is the purpose of the ductus venosus

Answer 4

shunts blood from umbilical vein to IVC (blood goes straight to heart)

Question 5

what is the purpose of the foramen ovale

Answer 5

shunt between RA to LA - allows oxygenated blood to left side of heart around the body and bypass the lungs

Question 6

what is the purpose of the ductus arteriosus

Answer 6

branch off of pulmonary trunk straight to descending aorta, blood bypasses the lungs to the body as lungs are non-functioning yet

Question 7

what changes happens to hormones and lungs in labour (3)

Answer 7

increased catecholamines (adrenaline) and cortisol, synthesis of lung fluid stops, vaginal delivery squeezes lungs

Question 8

what is visibly expected in a baby in the first few seconds if life (4)

Answer 8

blue –> pink, starts to breath, cries, cut cord

Question 9

what is the apgar score

Answer 9

a measure of how well the perinatal adaption is going measured at 1, 5 and 10 mins

Question 10

what components of the apgar score are there and what is normal

Answer 10

10 points maximum out of 5 categories, give 0 ,1 or 2 points for: HR, RR, colour, responsive and tone. normal is 8

Question 11

what can lead to low apgar scores

Answer 11

difficult birth, C section, fluid in lungs

Question 12

what circulatory changes happen at birth (6)

Answer 12

pulmonary vascular resistance drops, systemic resistance rises, oxygen tension rises, circulating prostaglandins drop, ductus arteriosus and venosus constrict, foramen ovale closes

Question 13

what happens in persistent pulmonary hypertension of the new born (PPHN)

Answer 13

pulmonary resistance remains high, ductus arteriosus does not shut and blood continues to bypass the lungs (no oxygenation)

Question 14

what are symptoms of PPHN

Answer 14

breathing problems eg grunt, hypoxia (blue), cold extremities, low systemic BP, low o2 sats

Question 15

how do you manage PPHN

Answer 15

ventilate and NO

Question 16

what is the main source of thermoregulation in babies and when does it kick in

Answer 16

non-shivering thermogenesis: breakdown of stored brown adipose tissue in response to catecholamines - not effective in first 12 hours

Question 17

what babies are at risk of hypothermia and why

Answer 17

preterm/ small babies: low stores of brown and subcut fat, large SA: volume

Question 18

how are babies kept warm in first few hours

Answer 18

keep dry, hat, skin to skin, blankets, incubator/ heated mattress

Question 19

what happens in regards to glucose homeostasis in first few hours of life (3)

Answer 19

drop in insulin and rise in glycogen, hepatic glycogen stores for glucose, ketones for brain

Question 20

wha reflex should be present at birth for breast feeding

Answer 20

rooting and sucking

Question 21

what happens to a babies oxygen curve at birth and why

Answer 21

shifts to the right as increased 2-3 BPG and feotal Hb becomes less useful

Question 22

where does haemotopoesis move to in a new born and what physiological blood abnormality doe they have

Answer 22

bone marrow - aneamia

Question 23

what causes physiological jaundice in a new born

Answer 23

liver enzyme pathway immature, rise in unconjugated bilirubin, breakdown of foetal Hb

Question 24

when does physiological newborn jaundice become pathological

Answer 24

when it is early or prolonged