abnormal labour

Question 1

induction of labour - incidence

Answer 1

~1/5 pregnancies
can be before or after due date
need fetal monitoring (higher risk)
need for cervical ripening - prostaglandins, balloon

Question 2

what is induction

Answer 2

an attempt is made to instigate labour artificially using medications and/or devices to ripen cervix
followed usually by artificial rupture of membranes (amniotomy)

Question 3

what is Bishop’s score

Answer 3

used to clinically assess the cervix
higher score = more progressive change there is in the cervix
indicates that induction is likely to be successful

Question 4

components of Bishop’s score

Answer 4

Question 5

process of induction of labour

Answer 5

amniotomy once cervix has dilated and effaced

once amniotomy performed, IV oxytocin used to achieve adequate contractions (unless contractions spontaneously start) - aim for 4-5 contractions in 10 mins

Question 6

what Bishop score is considered favourable for amniotomy

Answer 6

7

Question 7

what is an amniotomy

Answer 7

artificial rupture of the fetal membranes

usually using sharp device e.g. amnihook

Question 8

indications for induction

Answer 8

diabetes

post dates - term + 7days

maternal need for planning of delivery e.g. on treatment for DVT

fetal reasons - growth concerns, oligohydramnios

social/maternal request

Question 9

intrapartum complications - powers, passages, passenger

what may inadequate progress in labour be due to?

Answer 9

powers - inadequate uterine activity

passages - cephalopelvic disproportion (CPD), other reasons for obstruction e.g. fibroid

passenger - malposition, malpresentation

fetal distress

Question 10

evaluating progress in labour

Answer 10

combination of abdo and vaginal examiantions to determine - cervical effacement, cervical dilatation, descent of the fetal head through the maternal pelvis

Question 11

what define suboptimal progress in the active first stage of labour

Answer 11

cervical dilatation:

<0.5cm per hour for primagravid women

<1cm per hour for parous women

Question 12

inadequate uterine activity

Answer 12

inadequate contractions = fetal head will not descend and exert force on cervix = cervix will not dilate

Question 13

how can contractions be increased

what is important to exclude

Answer 13

synthetic IV oxytocin to the mother

increases strength and duration of contractions

exlude an obstructed labour in these circumstances, stimulation could result in ruptured uterus

Question 14

what is cephalopelvic disproportion

Answer 14

genuine CPD is relatively rare

means that the fetal head is in the correct position for labour but too large to negotiate the maternal pelvis and be born

caput (swelling on the baby’s head) and moulding (fetal skull bones start to cross) develop

Question 15

causes of obstruction in labour

Answer 15

CPD

placenta previa

fetal anomaly e.g. hydrocephaly

fibroids

Question 16

malposition of the baby

Answer 16

much more common than malpresentation

occipitoanterior is ideal presentation for birth

fetal head is in a suboptimal position for labour and relative CPD occiprs - occipitoposterior and occipitotrasnverse

Question 17

what is the ideal presentation for baby

Answer 17

longitudinal lie

vertex presentation

Question 18

malpresentation of baby

Answer 18

breech presentation - can be born vaginally

trasnverse - need C section

Question 19

how do we determine position of baby

Answer 19

vaginal examination feeling baby’s head (fontanelles)- posterior is triangle, anterior is diamond

Question 20

fetal distress

why does it happen

Answer 20

fetuses are well equipped to deal with stress of labour but some fetuses will not be able to cope

important to avoid causing too many contractions (uterine hyper-stimulation) as this can result in fetal distress due to insufficient placental blood flow

main causes of fetal distress - hypoxia, infection

rare causes - cord prolapse, placental abruption, vasa praevia

many cases of suspected distress have no cause found

Question 21

fetal monitoring - how is this done

Answer 21

intermittent ausculation of fetal heart

cardiotocography (CTG)

fetal blood sampling

fetal ECG

intermittent auscultation frequency increases during 2nd stage - every 5 mins

Question 23

fetal blood sampling

Answer 23

speculum used to take fetal scalp blood sampling

used when abnormal CTG

Question 24

what can we measure from fetal blood sampling

Answer 24

pH and base excess

lactic aid

pH gives a measure of likely hypoxaemia

mum has to be ~4cm dilated

can’t tell us about fetal bleeding or sepsis

Question 26

operative delivery

Answer 26

used when concerned about intrapartum complication

instrumental deliveries (forceps/ventouse) - ~15% births

elective C section ~20-30% of births (rates vary globally)

emergency CS ~20-25%

Question 27

3rd stage complications

Answer 27

retained placenta

post-partum haemorrhage - 4Ts

tears - graze, 1st-4th degree (3rd = involving anal sphincter complex, 4th = involving rectal mucosa)

Question 28

what is required for forceps/ventouse delivery

Answer 28

fully dilated

adequate anaelgesia

consented

baby in adequate and safe position for procedure

Question 29

4Ts for PPH - most common causes of 1y PPH

Answer 29

trauma

tone

thrombin - abnormal clotting

tissue - retained pregnancy tissue