Parturition

Question 1

what is the role of the placenta

Answer 1

hormone production
preferential acquisition nutrients and removal of toxins
gas exchange CO2 and O2

Question 2

why’s there increased fatal oxygen content

Answer 2

higher Hb concentrations (17g/dl)

higher affinity for o2

Question 3

why is there a shift to the left for fatal haemoglobin over maternal

Answer 3

reduced binding of 2-3 DPG to foetal gamma chains

increased pCO2 and relative acidosis on maternal side and vice very on the foetal

Question 4

why does 23DPG bind LESS effectively to foetal Hb

Answer 4

fetal Hb contains 2 alpha and 2 gamma chains

23-DPG prefers to bind to B chains and normally would shift curve to the right promoting unloading

Question 5

when does foetal lung surfactant get produced

Answer 5

from 24 weeks type 2 pneumocystis produce surfactant

Question 6

what is the structure and role of foetal lung surfactant

Answer 6

mixture of phospholipids PC and PG and apoproteins, SP-A, B, C, D

decreases surface tension at air-liquid interference in the alveoli - allows them to remain open at end expiration

Question 7

what is the synthesis of foetal lung surfactant stimulated by

Answer 7

by foetal glucocorticoids and thyroid hormones (less so)

Question 8

what does lack of surfactant lead to in a foetus

Answer 8

neonatal respiratory distress

Question 9

what therapies are available for lack of foetal surfactant

Answer 9

promote production antenatally - maternal glucocorticoid administration
replace in neonatal period - artificial surfactant - curosurf)

Question 10

what is the traditional view of the myometrium

Answer 10

single cells interconnect and function as an electrical syncytium

Question 11

what tissues make up the myometrium

Answer 11

fasciculi
smooth muscle bundles
communicating bridges

Question 12

what generates electrical potential in the myometrium

Answer 12

any cell can acts as a pacemaker to generate AP

mediated by Ca ions from channels and intracellular stores m- gap junctions involved

Question 13

what determines propagation along the myometrium

Answer 13

rapid action potential wave (global)
slower intercellular wave (local)
these allow contractions

Question 14

what happens to contraction interval and resting me bran potential when preparing for labour

Answer 14

decrease in contraction interval and increase in resting membrane potential

Question 15

what is the most common amount of days it takes before delivery occurs

Answer 15

around 280

Question 16

what is the diagnosis of labour

Answer 16

regular painful contractions
progressive effacement (thinning of the cervix) and dilation of the cervix
descent of the presenting part

Question 17

describe the first stage of labour

Answer 17

contractions of uterine muscles force baby towards cervix

cervical opening thins and widens as contractions of lengthwise uterine muscles pull it open

Question 18

describe the second stage of labour

Answer 18

uterine contractions are aided by mothers involuntary pushes with abdominal muscles
head moves through tilted cervix and birth canal
shoulders and rest of body move through the cervix and brith canal

Question 19

describe the third stage of labour

Answer 19

placenta separates from uterine wall and is delivered through the vagina

Question 20

what are the 7 cardinal movements of labour

Answer 20

descent 
engagement 
flexion 
internal rotation 
extension 
external rotation 
expulsion

Question 21

what are the three physiological differences between foetus and adult

Answer 21

fetal circulation is different
placenta and not lung is the site of gas exchange
these must be reversed at brith

Question 22

what is the difference between fetal circulation and neonatal circulation

Answer 22

FC - left ventricle to body and placenta, 1) right atrium, foramen ovale left ventricle, 2) RA, RV, lungs or ductus arteriosus (both try to bypass lungs)

NN - LV, body, RV, lungs

Question 23

what are the 5 points of the APGAR score

Answer 23

appearance 
pulse 
grimace
activity 
respiration 
two points to each

Question 24

when are the APGAR points measured

Answer 24

1, 5, 10 minutes after birth

Question 25

what are two examples of abnormal parturition

Answer 25

preterm birth

birth asphyxia

Question 26

what percentage of cf pregnancies occur in preterm

Answer 26

10 %

Question 27

what counts as a preterm baby

Answer 27

about 255 days rather than 282 ish

Question 28

how many babies a year are preterm

Answer 28

60,000

Question 29

what are the 4 morbidities associated with preterm birth

Answer 29

lung - respiratory distress
brain - intraventricular haemorrhage (cereal palsy)
gut - necrotising enterocolitis (malabsorption)
eye - retinopathy (blindness)

Question 30

how can you reduce risk of preterm consequences

Answer 30

corticosteroids, ventilation and artificial surfactant

Question 31

what 4 things can induce preterm labour by triggering cytokines

Answer 31

small uterine capacity
placental abruption
cervical weakness
infection

Question 32

how can birth asphyxia happen during contraction

Answer 32

compression of the myometrial arteries 
cessation of flow to placenta 
lack of gas exchange 
relative fetal hypoxia 
anaerobic metabolism 
gradual lactic acidosis

Question 33

what are the specific consequences of brith asphyxia

Answer 33

lactic acidemia
tissue
hypoxic-ischemic encephalopathy
cerebral palsy

Question 34

when is fetal stress more likely to occur

Answer 34

less reserve (low birthweight)
long labour 
placental function impaired

Question 35

what is a placental abruption

Answer 35

where the placenta breaks aways form the uterus and the space between is filled with blood

Question 36

what is the management of brith asphyxia

Answer 36

fetal HR monitor
measurement of fetal scalp pH
monitor ST segment changes
if in first stage of labour use C section if in second stage use forceps