99. labour Flashcards
Stages of labour?
Latent phase: irregular contractions, mucous plug, cervix beginning to efface up to 4cm
First stage: strong regular uterine contractions, cervical dilatation up to 10cm
Second stage: from full dilation to delivery of baby
Third stage: from birth of baby to expulsion of placenta
Define labour
regular painful contractions with cervical changes
mechnism of labour
Descent
Flexion
Internal rotation
Extension
Restitution
External rotation
Delivery of body
cardinal movements of labour
Descent
Flexion
Internal rotation
Extension
Restitution
External rotation
Delivery of body
Ideal foetal position
occiput anterior
left occiput anterior is ideal
entonox
gas and air
Gas and air contains a mixture of 50% nitrous oxide and 50% oxygen. This is used during contractions for short term pain relief.
IM diamorphine vs IM pethidine
Pethidine shorter
Diamorphine longer and more powerful
Braxton-Hicks Contractions
occasional irregular contractions of the uterus. They are usually felt during the second and third trimester.
Diagnosing labour
Show (mucus plug from the cervix) clear or bloody show
Rupture of membranes
Regular, painful contractions
Dilating cervix on examination
Active management of the third stage
intramuscular oxytocin
Rupture of membranes (ROM)
The amniotic sac has ruptured.
Spontaneous rupture of membranes (SROM)
The amniotic sac has ruptured spontaneously
Prelabour rupture of membranes (PROM)
The amniotic sac has ruptured before the onset of labour.
Preterm prelabour rupture of membranes (P‑PROM)
The amniotic sac has ruptured before the onset of labour and before 37 weeks gestation (preterm).
Prolonged rupture of membranes (also PROM)
The amniotic sac ruptures more than 18 hours before delivery.
cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation
vaginal progesterone to maintain pregnancy
cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation, who have had a previous premature birth or cervical trauma (e.g. colposcopy and cone biopsy)
Cervical cerclage
Complications of PPROM
fetal: prematurity, infection, pulmonary hypoplasia
maternal: chorioamnionitis
Investigation PPROM (premature, prelabour)
A sterile speculum examination should be performed (to look for pooling of amniotic fluid in the posterior vaginal vault)
but digital examination should be avoided due to the risk of infection.
Ultrasound may also be useful to show oligohydramnios.
Management PPROM prolonged
- admission
- regular observations to ensure chorioamnionitis is not developing
- oral erythromycin should be given for 10 days 250mg four times daily
- antenatal corticosteroids should be administered to reduce the risk of respiratory distress syndrome
- delivery should be considered at 34 weeks of gestation - there is a trade-off between increased risk of maternal chorioamnionitis with a decreased risk of respiratory distress syndrome as the pregnancy progresses
Preterm labour with intact membranes
regular painful contraction and cervical dilatation, without rupture of the amniotic sac.
Tests if diagnostic doubt about PPROM premature prelabour
Insulin-like growth factor-binding protein-1 (IGFBP-1)
Diagnosis of preterm labour with intact membranes
Less than 30 weeks gestation, clinical assessment alone is enough to offer management of preterm labour.
More than 30 weeks gestation, a transvaginal ultrasound can be used to assess the cervical length. When the cervical length on ultrasound is less than 15mm, management of preterm labour can be offered. A cervical length of more than 15mm indicates preterm labour is unlikely.
Tocolysis
involves using medications to stop uterine contractions. Nifedipine, a calcium channel blocker, is the medication of choice for tocolysis. Atosiban is an oxytocin receptor antagonist that can be used as an alternative when nifedipine is contraindicated.
When is tocolysis used
Tocolysis can be used between 24 and 33 + 6 weeks gestation in preterm labour to delay delivery and buy time for further fetal development, administration of maternal steroids or transfer to a more specialist unit (e.g. with a neonatal ICU). It is only used as a short term measure (i.e. less than 48 hours).
Bishop score
scoring system used to determine whether to induce labour
Score of 8 or more on bishop score
predicts a successful induction of labour. A score below this suggests cervical ripening may be required to prepare the cervix.
Options for induction of labour
- membrane sweep
- vaginal prostaglandin E2
- Cervical ripening balloon
- Artificial rupture of membranes
complication of induction of labour with vaginal prostaglandins?
Uterine hyperstimulation
Criteria for uterine hyperstimulation
Individual uterine contractions lasting more than 2 minutes in duration
More than five uterine contractions every 10 minutes
Management uterine hyperstimulation
Removing the vaginal prostaglandins, or stopping the oxytocin infusion
Tocolysis with terbutaline
Indications for continuous CTG monitoring
Sepsis
Maternal tachycardia (> 120)
Significant meconium
Pre-eclampsia (particularly blood pressure > 160 / 110)
Fresh antepartum haemorrhage
Delay in labour
Use of oxytocin
Disproportionate maternal pain
5 key features to look for in CTG
Contractions – the number of uterine contractions per 10 minutes
Baseline rate – the baseline fetal heart rate
Variability – how the fetal heart rate varies up and down around the baseline
Accelerations – periods where the fetal heart rate spikes
Decelerations – periods where the fetal heart rate drops
Reassuring baseline rate and variability
110-160
5-25
Non-reassuring base line rate and variability
100-109 or 160-180
<5 for 30-50 mins
> 25 for 15-25 mins
Abnormal baseline rate and variability
<100 or >180
Less than 5 for over 50 minutes or
More than 25 for over 25 minutes
what are accelerations a sign of?
Accelerations are generally a good sign that the fetus is healthy, particularly when occurring alongside contractions of the uterus
Early decelerations
gradual dips and recoveries in heart rate that correspond with uterine contractions. The lowest point of the declaration corresponds to the peak of the contraction. Early decelerations are normal and not considered pathological. They are caused by the uterus compressing the head the fetus, stimulating the vagus nerve of the fetus, slowing the heart rate.
Late decelerations
are gradual falls in heart rate that starts after the uterine contraction has already begun. There is a delay between the uterine contraction and the deceleration. The lowest point of the declaration occurs after the peak of the contraction. Late decelerations are caused by hypoxia in the fetus, and are a more concerning finding. They may be caused by excessive uterine contractions, maternal hypotension or maternal hypoxia.
urgent fetal blood sampling
Variable decelerations
abrupt decelerations that may be unrelated to uterine contractions. There is a fall of more than 15 bpm from the baseline. The lowest point of the declaration occurs within 30 seconds, and the deceleration lasts less than 2 minutes in total. Variable decelerations often indicate intermittent compression of the umbilical cord, causing fetal hypoxia. Brief accelerations before and after the deceleration are known as shoulders, and are a reassuring sign that the fetus is coping.
Prolonged decelerations
last between 2 and 10 minutes with a drop of more than 15 bpm from baseline. This often indicates compression of the umbilical cord, causing fetal hypoxia. These are abnormal and concerning.
4 types of decelerations
early
late
variable
prolonged
A CTG is normal with respect to decelerations when…
no decelerations, early decelerations or less than 90 minutes of variable decelerations with no concerning features.
Four categories of CTG?
Normal
Suspicious: a single non-reassuring feature
Pathological: two non-reassuring features or a single abnormal feature
Need for urgent intervention: acute bradycardia or prolonged deceleration of more than 3 minutes
Management of prolonged fetal bradycardia
3 minutes – call for help
6 minutes – move to theatre
9 minutes – prepare for delivery
12 minutes – deliver the baby (by 15 minutes)
Sinusoidal CTG
A sinusoidal CTG is a rare pattern to be aware of, as it can indicate severe fetal compromise. It gives a pattern similar to a sine wave, with smooth regular waves up and down that have an amplitude of 5 – 15 bpm. It is usually associated with severe fetal anaemia, for example, caused by vasa praevia with fetal haemorrhage.
Patient Controlled Analgesia
Patient-controlled intravenous remifentanil. This involves the patient pressing a button at the start of a contraction to administer a bolus of this short-acting opiate medication.
Patient-controlled analgesia requires careful monitoring. There needs to be input from an anaesthetist, and facilities in place if adverse events occur. This includes access to naloxone for respiratory depression, and atropine for bradycardia.
adverse effects of epidural
Headache after insertion
Hypotension
Motor weakness in the legs
Nerve damage
Prolonged second stage
Increased probability of instrumental delivery
What is cord prolapse
The umbilical cord descends below the presenting part of the fetus and through the cervix into the vagina, after rupture of the fetal membranes. There is a significant danger of the presenting part compressing the cord, resulting in fetal hypoxia.
Most significant risk factor for cord prolapse
abnormal lie after 37 weeks gestation (i.e. unstable, transverse or oblique)
When should you suspect cord prolapse
Where there are signs of fetal distress on the CTG
Management of cord prolapse
- oragnise emergency CS
- Don’t handle cord or push it back in
- Push presenting part upwards to prevent it compressing the cord
- woman can lie in the left lateral position (with a pillow under the hip) or the knee-chest position (on all fours), using gravity to draw the fetus away from the pelvis and reduce compression on the cord.
- Tocolytic medication (e.g. terbutaline) can be used to minimise contractions whilst waiting for delivery by caesarean section.
Management of shoulder dystocia
HELPERR(R)
H- call for help
E - evaluate for episiotomy
L - legs in McRoberts
P - Suprapubic pressure
E - Enter pelvis
R - rotational manoeuvre
R - remove posterior arm
(R - replace head and CS)
What medication is given after instrumental delivery?
single dose of co-amoxiclav
Indictions for instrumental delivery
Failure to progress
Fetal distress
Maternal exhaustion
Control of the head in various fetal positions
Risks to baby with instrumental delivery
Cephalohaematoma with ventouse
Facial nerve palsy with forceps
Rarely:
Subgaleal haemorrhage (most dangerous)
Intracranial haemorrhage
Skull fracture
Spinal cord injury
Which of the mothers nerves may be compressed with forceps delivery
Femoral nerve
Obturator nerve
First-degree tear
Injury limited to the frenulum of the labia minora (where they meet posteriorly) and superficial skin
Second degree tear
including the perineal muscles, but not affecting the anal sphincter
Third degree tear
including the anal sphincter, but not affecting the rectal mucosa
3A = <50% of external anal sphincter
3B = >50% of the external anal sphincter
3C = external and internal sphincters affected
Fourth degree tear
including the rectal mucosa
Management first degree tears
First-degree tears usually do not require any sutures.
Management of secondary degree tears
sutures on ward
Management of third and fourth degree tears
sutures in theatre
Preventing tears
Perineal massage is a method for reducing the risk of perineal tears. It involves massaging the skin and tissues between the vagina and anus (perineum). This is done in a structured way from 34 weeks onwards to stretch and prepare the tissues for delivery.
When is active management of the 3rd stage indicated
Active management is routinely offered to all women to reduce the risk of postpartum haemorrhage.
It is also initiated if there is:
- Haemorrhage
- More than a 60-minute delay in delivery of the placenta (prolonged third stage)
Steps of active management of the third stage
- IM oxytocin 10IU
- Controlled cord traction
- After placenta delivered, massage uterus until firm
Definiton PPH
bleeding after delivery of the baby and placenta
500ml after a vaginal delivery
1000ml after a caesarean section
Severity classifications PPH
Minor PPH – under 1000ml blood loss
Moderate PPH – 1000 – 2000ml blood loss
Severe PPH – over 2000ml blood loss
Priamary vs secondary PPH
Primary PPH: bleeding within 24 hours of birth
Secondary PPH: from 24 hours to 12 weeks after birth
Causes of PPH
T – Tone (uterine atony – the most common cause)
T – Trauma (e.g. perineal tear)
T – Tissue (retained placenta)
T – Thrombin (bleeding disorder)
Most common cause PPH
uterine atony
Preventing PPH
Treating anaemia during the antenatal period
Giving birth with an empty bladder (a full bladder reduces uterine contraction)
Active management of the third stage (with intramuscular oxytocin in the third stage)
Intravenous tranexamic acid can be used during caesarean section (in the third stage) in higher-risk patients
Management PPH
- stabilise
- mechanical:
- rubbing the fundus
- catherterisation - medical:
- oxytocin slow IV injection –> continuous infusion IV
- ergometrine slow IV or IM (contraindicated in hypertension)
- carboprost IM (CAUTION IN ASTHMA)
- misoprostol sublingual
- tranexamic acid - surgical:
- Intrauterine balloon tamponade
- B-Lynch suture
- Uterine artery ligation
- Hysterectomy is the “last resort”
the RCOG state that the intrauterine balloon tamponade is an appropriate first-line ‘surgical’ intervention for most women where uterine atony is the only or main cause of haemorrhage
Investigations secondary PPH
Ultrasound for retained products of conception
Endocervical and high vaginal swabs for infection
Causes secondary PPH
RPOC
infection
Management secondary PPH
Surgical evaluation of retained products of conception
Antibiotics for infection
What PPH drug should you be cautious of in HTN
Ergometrine
What PPH drug should you be cautious of in asthma
Carboprost
Category 3 CS
Delivery is required, but mother and baby are stable.
category 4 CS
This is an elective caesarean, as described above.
Category 2 CS
There is not an imminent threat to life, but caesarean is required urgently due to compromise of the mother or baby. Decision to delivery time is 75 minutes.
Category 1 CS
There is an immediate threat to the life of the mother or baby. Decision to delivery time is 30 minutes.
Specific risks of spinal
Nerve damage (spinal anaesthetic)
Haematoma (spinal anaesthetic)
Why are H2 receptor antagonists (e.g. ranitidine) or proton pump inhibitors (e.g. omeprazole) given before caeserean section?
risk of aspiration pneumonitis during caesarean section, caused by acid reflux and aspiration during the prolonged period lying flat. H2 receptor antagonists (e.g. ranitidine) or proton pump inhibitors (e.g. omeprazole) are given before the procedure to reduce the risk of this happening.
What drugs are used in CS to prevent complications
H2 receptor antagonists (e.g. ranitidine) or proton pump inhibitors (e.g. omeprazole) before the procedure
Prophylactic antibiotics during the procedure to reduce the risk of infection
Oxytocin during the procedure to reduce the risk of postpartum haemorrhage
Venous thromboembolism (VTE) prophylaxis with low molecular weight heparin
Sepsis 6
Three tests:
Blood lactate level
Blood cultures
Urine output
Three treatments:
Oxygen to maintain oxygen saturations 94-98%
Empirical broad-spectrum antibiotics
IV fluids
Two key causes of sepsis in pregancy
Chorioamnionitis
Urinary tract infections
In maternal sepsis, if there was fetal distress, how would the baby be delivered
Emergency caesarean section may be indicated when there is fetal distress, guided by a senior obstetrician. General anaesthesia is usually required for women with sepsis, as spinal anaesthesia is avoided.
Management maternal sepsis
Very heavy-hitting antibiotics are required, needing to cover gram-positive, gram-negative and anaerobes. There are also significant consequences of inadequate treatment. Example regimes include piperacillin and tazobactam (tazocin) plus gentamicin, or amoxicillin, clindamycin and gentamicin.
Acute onset, around time of delivery
Shortness of breath
Hypoxia
Hypotension
Coagulopathy
Haemorrhage
Tachycardia
Confusion
Seizures
Cardiac arrest
amniotic fluid embolisation
Management amniotic fluid embolisation
supportive
ABCDE
CPR
immediate caeserean
What is uterine rupture?
the muscle layer of the uterus (myometrium) ruptures. With an incomplete rupture, or uterine dehiscence, the uterine serosa (perimetrium) surrounding the uterus remains intact. With a complete rupture, the serosa ruptures along with the myometrium, and the contents of the uterus are released into the peritoneal cavity.
Presentation of uterine rupture
Uterine rupture presents with an acutely unwell mother and abnormal CTG. It may occur with induction or augmentation of labour, with signs and symptoms of:
Abdominal pain
Vaginal bleeding
Ceasing of uterine contractions
Hypotension
Tachycardia
Collapse
Management uterine rupture
- stabilise/resus
- transfusion?
- emergency Caesarean and repair
Risk factors for uterine rupture
Vaginal birth after caesarean (VBAC)
Previous uterine surgery
Increased BMI
High parity
Increased age
Induction of labour
Use of oxytocin to stimulate contractions
Presentation of uterine inversion
Uterine inversion typically presents with a large postpartum haemorrhage. There may be maternal shock or collapse.
An incomplete uterine inversion may be felt with manual vaginal examination. With a complete uterine inversion, the uterus may be seen at the introitus of the vagina.
why shouldn’t you pull too hard on the cord during active management of the 3rd stage of labour
risk of uterine inversion
Management uterine inversion
- Johnson manoeuvre (pushing it back up)
- hydrostatic measures
- surgery
VBAC
planned VBAC is an appropriate method of delivery for pregnant women at >= 37 weeks gestation with a single previous Caesarean delivery
around 70-75% of women in this situation have a successful vaginal delivery
contraindications include previous uterine rupture or classical caesarean scar
GBS prophylaxis in labour
benzylpenicillin
what to do if late decelerations
fetal blood sampling
A pH of >7.2 in labour is considered normal. Urgent delivery should be considered if there is fetal acidosis.
Layers you cut through in c-section
Skin
Subcutaneous tissue :Superficial fascia, Deep fascia
Rectus sheath
Rectus abdominis muscle (not cut, rather pushed laterally following incision of the linea alba)
Parietal peritoneum
Uterus
Indications for continuous CTG monitoring
As per NICE guidelines; the following would warrant continuous CTG monitoring if any of the following are present or arise during labour;
suspected chorioamnionitis or sepsis, or a temperature of 38°C or above
severe hypertension 160/110 mmHg or above
oxytocin use
the presence of significant meconium
fresh vaginal bleeding that develops in labour - this was a new point added to the guidelines in 2014
Management of failure to progress
Amniotomy, also known as artificial rupture of membranes (ARM) for women with intact membranes
Oxytocin infusion
Instrumental delivery
Caesarean section
what is considered delay in the 1st stage?
Less than 2cm of cervical dilatation in 4 hours
Slowing of progress in a multiparous women
what is a parotogram
Women are monitored for their progress in the first stage of labour using a partogram.
Recorded on a partogram are:
Cervical dilatation (measured by a 4-hourly vaginal examination)
Descent of the fetal head (in relation to the ischial spines)
Maternal pulse, blood pressure, temperature and urine output
Fetal heart rate
Frequency of contractions
Status of the membranes, presence of liquor and whether the liquor is stained by blood or meconium
Drugs and fluids that have been given
alert and action lines partogram
Alert line is an indication for amniotomy (artificially rupturing the membranes) and a repeat examination in 2 hours.
Crossing the action line means care needs to be escalated to obstetric-led care and senior decision-makers for appropriate action.
theres an o in action and obsteric
delay in second stage?
2 hours in a nulliparous woman
1 hour in a multiparous woman
delay in 3rd stage?
More than 30 minutes with active management
More than 60 minutes with physiological management
