Labour, delivery, and analgesia Flashcards
Discuss the anatomy of the maternal pelvis
ilium, pubic symphysis, pubic bone, iliac crest, ASIS, sacrum…
Discuss the anatomy of the fetal skull
ant and post fontanelle
frontal, coronal, saggital suture
frontal, parietal, occipital bone
Define vertex
the highest/apical point= fetal head (Vertix position)
List two mechanisms of normal labour and delivery
effacement and dilation of cervix
expulsion of the fetus by uterine contractions
List three factors that promote the initiation of labour
oxytocin, prostaglandins, CRH, inflammatory mediators
List two factors that promote pregnancy versus labour
progesterone
nitric oxide
relaxin
catecholamines
What is the source of progesterone during pregnancy?
corpus luteum for first 8 weeks then placenta
What is the MOA of mifepristone?
progseterone antagonist- increases myometrial contractility
What is the function of progesterone in pregnancy?
decreases uterine oxytocin receptor sensitivity and therefore promotes uterine smooth muscle relaxation
Where is oxytocin produced from?
post pituitary
What is the function of oxytocin?
stimulate uterine contractions
What is the effect of prostaglandins on labour?
promotes cervical ripening and stimulate uterine contractility
What is effacement?
Effacement refers to the thinning of the cervix during labor= ripening
Name one factor that promotes cervical ripening
prostaglandins, inflammatory cells
What happens to the collagen in the cervix during effacement?
concentration of collagen decreases, the cervix becomes softer and ready to dilate
Which score is used to assess cervical ripening?
Bishop’s score
How do you when the cervix is dilated?
dilatation of the external os
How do you know when effacement has taken place?
when the whole cervix has been ‘taken up’ into the lower segment of the uterus. Begins with the internal os, proceeds downwards to the external os until the cervical tissue becomes continuous with the uterine walls
When is a woman said to be in labour?
regular uterine contractions and fully effaced cervix
+spontaneous rupture of membranes and regular uterine activity
Does spontaneous rupture of membranes occur before or after regular uterine activity?
majority occur after uterine activity. Pre term rupture of membranes is when waters break before lady goes into labour (before 37 weeks)
How can rupture of membranes be visualised?
speculum- pool of liquor can be seen in posterior vaginal fornix
Name two complications of rupture of membranes?
ascending infection
chorioamnionitis
maternal and fetal sepsis (Rare)
How many stages are there in labour?
3
What does the first stage of labour comprise?
onset of labour until cervix is fully dilates
- latent (cervical effacement +3-4cm dilated)
- active (cervical dilatation)
What does the second stage comprise?
from cervical dilatation (10cm) until baby is delivered
What are the two phases of the second stage of labour?
Propulsive – from full dilatation until the head has descended onto the pelvic floor
Expulsive – from the time the mother has an irresistible urge to bear down and push until the baby is delivered
What is the third stage of labour?
From delivery of the baby until expulsion of the placenta and membranes
Name one risk associated with the third stage of labour
uterine inversion
How is engagement determined?
abdominally in fifths of fetal head palpable above the pelvic brim
List four assessments that should be conducted in labour
baseline recordings of maternal parameters
length, strength, frequency of contractions
foetal movements?
Spontaneous rupture of membranes?
abdo exam- fundal height, lie, presentation, engagement, auscultation
CTG
vaginal exam every 4 hours by the same person
What might meconium staining in the vagina suggest?
fetal distress
What might moulding seen in the vagina suggest?
obstructed labour
List three things you should assess for during vaginal exam during labour
meconium dilatation of cervic station of presenting part position of head moulding/caput?
What is caput succedaneum?
swelling of the scalp in a newborn. It is most often brought on by pressure from the uterus or vaginal wall during a head-first (vertex) delivery
What is station of the presenting part?
The station of the presenting part is recorded with respect to the ischial spines.
Spines is zero station.
List three positions that the fetal head can be in
L/R occipitoposterior
L/R occipitotransverse
L/R occipitoanterior
How is caput succedaneum classified?
Caput’ (succedaneum) is oedema of the scalp owing to pressure of the head against the rim of the cervix and is classified arbitrarily as ‘+’, ‘++’, or ‘+++’.
What is moulding?
describes the change in head shape, which occurs during labour, made possible by movement of the individual scalp bones.
How is moulding classified?
It is classified arbitrarily as ‘+’ if the bones are opposed, ‘++’ if the bones overlap but can be reduced, and ‘+++’ if the bones overlap, but cannot be reduced.
Is meconium a worrying sign?
Meconium is in itself not concerning. A healthy term baby will often pass meconium during labour. This will be thin and green-brown in colour. Thick meconium, green (pea-soup) can be a sign of fetal hypoxia or acidosis.
What is administered during the second stage of labour?
IM oxytocin after delivery of anterior shoulder
Why is oxytocin administered?
to reduce the risk of postpartum haemorrhage
What is a partogram?
Provides a graphic record of clinical findings and any relevant events during labour.
State three components of a partogram
Records maternal observations (BP, HR, temp), fetal heart rate, progressive cervical dilatation, descent of the presenting part, strength and frequency of contractions, and colour of amniotic fluid.
For how long is uterine activity recorded for during labour?
10 mins
Will a primiparous or multiparous labour take longer?
primiparous takes longer
What is precipitate labour?
expulsion of the fetus less then 2-3 hours of onset of contractions
Name one complication of precipitate labour?
placental abruption
fetal distress
How is a diagnosis of slow labour/delay in labour made?
cervical dilatation <2 cm in 4 hours
What is malpresentation and provide two examples?
Any non-vertex position
e.g. face, brow, breech, shoulder
List three risk factors/associations for breech
multiple pregnancy bicornate uterus fibroids placenta praevia polyhydamnios oligohydramnios neural tube defect
Before C-section, what should be tried with a baby in breech position?
external cephalic version = procedure used to help turn a baby in the womb before delivery
Define breech birth
A breech baby, or breech birth, is when your baby’s feet or buttocks are positioned to come out of your vagina first.
Define maposition
abnormal position of the vertex relative to the maternal pelvis
Define prolonged pregnancy
> 42 weeks
Name two risks associated with prolonged pregnancy
intrauterine death
intrapartum hypoxia
When is induction of labour offered in prolonged pregnancy with no complications?
between 41 and 42 weeks
What is the most common indication for induction of labour?
prolonged pregnancy
List three indications for induction of labour (IOL), aside from prolonged labour
Maternal diabetes, including gestational diabetes
Twin pregnancy
Pre-labour rupture of membranes
Fetal growth restriction and suspected fetal compromise
Hypertensive disorders of pregnancy including pre-eclampsia
Deteriorating maternal medical conditions (e.g. cardiac or renal disease)
Maternal request
State two contraindications to IOL
Situations were vaginal delivery is contraindicated (e.g. placenta praevia/transverse lie)
Caution in previous caesarean section or uterine surgery (increased risk of scar rupture)
Risk of hyperstimulation in those who have had a previous precipitate labour
State three methods for IOL
prostaglanding gel/tablet
cooks balloon
artifical rupture of membrane
syntocinon (synthetic oxytocin)
Why is CTG monitoring indicated during pharamcological IOL?
pharmacological preparations all cause uterine contractions and have the potential to reduce uterine blood flow and compromise the fetus
Which IOL methods can be used for unfavourable cervix? (bishop score<6)
prostaglandins and cooks balloon
Which IOL methods can be used for favourable cervix? (bishop score >6)
artifical rupture of membranes
oxytocin
Name one risk associated with prostaglandin induction?
hyperstimulation
Define hyperstimulation
> 5 contractions: 10 mins for 20 mins associated with signs of fetal compromise
What is augmentation?
the process of accelerating labour which is already underway
Name two non-pharmacological pain relief options in labour
1:1 support
environment
birthing pools
education
Name two pharmacological agents for pain relief in labour
inhaled analgesics- entonox
opioids- diamorphine + antiemetic
Pudendal analgesia
Epidural/spinal
GA
List two options for regional anaesthetics
epidural
spinal
State three complications of regional anaesthetics
dural puncture headache hypotension local anaesthetic toxicity accidental total spinal block neurological complications- peripheral nerve injury bladder dysfunction
List three risks associated with general anaesthesia during labour
Reduced gastro-oesophageal tone
Increased intra-abdominal mass
Reduced gastric emptying
Regurgitation of gastric contents and aspiration - leading to pneumonitis
Difficult and failed intubation more likely
What is a first degree perineal tear?
Injury to the vaginal epithelium and vulval skin only
Second degree perineal tear?
Injury to the perineal muscles, but not the anal sphincter
Third degree?
Injury to the perineum involving the anal sphincter complex
Fourth degree?
Injury to the perineum involving the anal sphincter complex and anal/rectal mucosa
What is an episiotomy?
Episiotomy, also known as perineotomy, is a surgical incision of the perineum and the posterior vaginal wall generally done by a midwife or obstetrician.
Name two indications for episiotomy
- a rigid perineum which is preventing delivery
- If it is judged that a large tear is imminent
- Most instrumental deliveries (ventouse or forceps)
- Suspected fetal compromise
- Shoulder dystocia (to improve access to the birth canal)
List three components of immediate post-birth care
Skin-to-skin contact if no neonatal resus required – supports physiological transition of the newborn and mother
Neonatal thermoregulation, respiratory regulation, increases successful breastfeeding
Maternal stimulation of oxytocin, which increases uterine contractions and milk production
Rhesus bloods and Anti-D if required
Assessment of risk postpartum psychosis/depression, child protection or social concerns
6-hour discharge if mother and baby are well
List three assessments of the newborn immediately post-birth
APGAR 1,5,10 mins Clamp cut umbilical cord Birth weight temp Head, facial, digits, spine, external rotation First micturation and feed
What should be administered to the baby immediately post-birth?
vit K
List three assessment of the mother immediately post-birth
vagina, uterine fundus observe for trauma- e.g. perineal tear baseline obs record first micturition after birth categories VTE risk
List three benefits of breast feeding for baby
reduced risk of infections reduced risk of vomiting and diarrhoea reduced risk of obesity reduced risk of CDV in adult strong emotional bond
State three benefits of breastfeeding for mum
lowers risks of breast cancer, ovarian cancer, osteoporosis, CVD, obesity
What should be discussed/assessed in the first 10 days post birth
Postnatal depression assessment
Physical exam of mum and baby
Discuss contraception
Emotional problems, support breastfeeding and parenting
Which investigations should you carry out on the mother at the late postnatal exam? (6 weeks)
FBC
cervical smear
List three post natal complications
Anaemia
Bowel problems
Breast Problems
Perineal breakdown
Incontinence
Puerperal pyrexia
Secondary PPH
VTE
Mental Health Problems; Postnatal depression, Postpartum psychosis
Name one breast complication in women
mastitis= blocked mammary duct
Why does incontinence arise in women post natal?
neuropraxia= impaired pudendal nerve function after compression during delivery
What is puerperal pyrexia?
temp >38 degrees on any occasion in the first 14 days after birth
Name two causes of puerperal pyrexia
genital tract infection (endometritis)
UTI
DVT
Infection of breast
List two risk factors for maternal sepsis
maternal obesity
c-section
What is the treamtent for DVT post partum?
LMWH
Differential for DVT?
thrombophlebitis 1%
List three signs of postpartum psychosis
fear insomnia agitation irritation anger fear for own health and baby grandiosity, suspisciousness, depression
Where should mother go with postpartum psychosis?
admission to a mother and baby unit with baby
How to distinguish between miscarriage and stillbirth?
miscarriage<24 weeks
stillbirth >24 weeks
List three associations with stillbirth
advanced maternal age maternal obesity social deprivation smoking non-white domestic violence
Discuss three causes of stillbirth
fetal: fetal growth restriction, infection, anaemia, cord obstruction
maternal: DKA, diabetes, Ab production, reduced oxygen state
placental mediated: pre-eclampsia, placental abruption, antiphospholipid syndrome. cocain use, smoking
State two placental mediated causes of still birth
uterine rupture
placenta praevia
uterine abnormality
What are the components of still birth after care?
psychological care memory box with photos, hand footprints post-mortem support groups suppression of lactation funeral arrangements
How is an active labour diagnosed?
fully effaced + around 3 cm dilated AND regular painful contractions
(+persistent backpain, spontaneous rupture of membranes, nausea/vomiting/diarrhoea)
What are Braxton-Hicks contractions?
Braxton Hicks are when the womb contracts and relaxes. Sometimes they are known as false labour pains. Not all women will have Braxton Hicks contractions.
What happens during the first stage of labour?
cervix fully dilated: 10 cm
What happens in the second stage of labour
delivery of baby
What happens in the third stage of labour?
delivery of placenta
List three mechanisms of birth (e.g. engagement)
engagement descent and flexion internal rotation delivery by extension external rotation restitution delivery of shoulders
What is a partogram?
A partogram is used to record all observations made when the woman is in labor.
What is measured on a partogram?
- fetal condition (fetal heart rate, color of amniotic fluid and molding of the fetal skull)
- Maternal condition (pulse, BP, temperature, urine output and urine for protein and acetone)
- The progress of labor is monitored by cervical dilatation, descent of head and uterine contractions
- A separate space is given to enter drugs, IV fluids and oxytocin
Name three differences between a spinal and epidural
Spinal- local anaesthetic directly into spinal cord (subarachnoid space) while epidural injected outside the dura, therefore affects nerve roots
Spinal is a one off dose and lasts 2 hours while epidural can have catheter inserted to top up analgesia
Onset in spinal is much faster- around 5 mins while epidural is slower- around 25-30 mins
epidural can be cervical, thoracic, or lumbar spine, while spinal must be L3/L4
List three analgesic options during labour
entonox diamorphine IM epidural pudendal and perineal infiltration bath, birthing pool
What are the first signs of labour?
mucus plug- pink substance
ruptured amniotic sac- ‘my water broke’
both stimulate contractions
What are BRaxton hicks contractions?
pre-labour contractions
What is the maximum duration of the first stage of labour?
<12 hours
What are the 3 P’s of the second stage of labour?
powers- 4-5 times every 10 mins
passage
passenger
