Labour and Delivery Flashcards
Define labour?
When do labour and delivery normally occur?
Labour may be defined as the onset of regular and painful contractions associated with cervical dilation and descent of the presenting part
Between 37 and 42 weeks gestation
What are the three stages of labour?
First stage - from onset until 10cm cervical dilation
Second stage - from 10cm cervical dilation until delivery of baby
Third stage - from delivery of baby to delivery of placenta
What changes to the cervix happen in the first stage of labour?
Cervical dilation - opening up
Effacement - getting thinner
Mucus plug falls out creating space for baby to pass through
What are the 3 phases to the first phase of delivery?
Latent phase = from 0 to 3cm - progresses at 0.5cm per hour - irregular contractions
Active phase = from 3 to 7cm - progresses at 1cm per hour - regular contractions
Transition phase = from 7 to 10cm - progresses at 1cm per hour - strong and regular contractions
What are Braxton-Hicks contractions?
Occasional irregular contractions of the uterus (felt during 2nd and 3rd trimester)
Not indicating the onset of labour - staying hydrated and relaxing reduces these contractions.
What are the signs of labour?
Show (mucus plug from the cervix)
Rupture of membranes
Regular, painful contractions
Dilating cervix on examination
What are the latent first stage of labour and the established first stage of labour?
Latent first stage = painful contractions, changes to the cervix, with effacement and dilatation up to 4cm
Established first stage = regular, painful contractions, dilatation of the cervix from 4cm onwards
What is prematurity?
Birth before 37 weeks gestation
When are babies considered non-viable?
Before 23 weeks gestation
23-24 weeks: baby not considered for resuscitation if the do not not show signs of life
24 weeks onwards: increased chance of survival
What is the WHO classification of prematurity?
Under 28 weeks: extreme preterm
28 – 32 weeks: very preterm
32 – 37 weeks: moderate to late preterm
What are the 2 options for prophylaxis of pre-term labour? Who is it offered to?
Vaginal progesterone- given via pessary or gel; progesterone maintains pregnancy and prevents labour by decreasing activity of the myometrium and preventing cervix remodelling in preparation for delivery
- Offered to woemn with a cervical length <25mm on vaginal USS between 16 and 24 weeks gestation
Cervical cerclage- stitch in cervix to keep it closed- removed when woman goes into labour/ reaches term
- Offered to woemn with a cervical length <25mm on vaginal USS between 16 and 24 weeks gestation who have had a previous premature birth or cervical trauma eg colposcopy or cone biopsy
What is preterm prelabour rupture of membranes?
(PPROM)
Occurs in ~2% pregnancies but is associated with around 40% preterm deliveries
Where the amniotic sac ruptures before the onset of labour and in a preterm pregnancy (under 37 weeks gestation)
How is P-PROM diagnosed?
Speculum examination revealing pooling of amniotic fluid in the posterior vaginal vault of vagina - no tests are required
Digital examination avoided- risk of infection
USS- may reveal oligohydramnios
What tests can be used to confirm the diagnosis of P-PROM?
- Insulin-like growth factor-binding protein-1 (IGFBP-1)- present in amniotic fluid, can be tested for in vaginal fluid if there is doubt about rupture of membranes
- Placental alpha-microglobin-1 (PAMG-1)- similar alternative as above
What is the management of P-PROM? What are some potential complications?
Admission
Regular observations to ensure chorioamnionitis is not developing
Prophylactic antibiotics given to prevent chorioamnionitis
- Erythromycin 250mg qds for 10 days or until labour is estabilished if within 10 days
Antenatal corticosteroids to reduce the risk of RDS
Induction of labour may be offered from 34 weeks -there is a trade-off between increased risk of maternal chorioamnionitis with a decreased risk of respiratory distress syndrome as the pregnancy progresses
COMPLICATIONS
- Fetal: prematurity, infection, pulmonary hypoplasia
- Maternal: chorioamnionitis
What antibiotics are recommended to prevent chorioamnionitis?
Erythromycin 250mg 4 times daily for 10 days or until labour is established if within 10 days
What is preterm labour with intact membranes? How is this diagnosed?
Preterm labour with intact membranes with regular painful contraction and cervical dilatation, without rupture of the amniotic sac
- Speculum exam to assess for cervical dilatation
- If > 30 weeks: offer TV USS to assess cervical length
- If cervical length < 15mm, mx of preterm labour can be offered
- If > 15mm, preterm labour is unlikely
- Alternative to vaginal USS: fetal fibronectin found in vagina during labour, if <50ng/ml then preterm labour is unlikely
What is included in the management of preterm labour?
Fetal monitoring (CTG or intermittent auscultation)
Tocolysis with nifedipine: nifedipine is a calcium channel blocker that suppresses labour
Maternal corticosteroids: can be offered before 35 weeks gestation to reduce neonatal morbidity and mortality
IV magnesium sulphate: can be given before 34 weeks gestation and helps protect the baby’s brain
Delayed cord clamping or cord milking: can increase the circulating blood volume and haemoglobin in the baby at birth
What is tocolysis?
- Medication to stop uterine contractions - nifedipine, a CCB, is the medication of choice for tocolysis
- Alternative- atosiban, oxytocin receptor antagonist
- Can be used between 24 and 33+6 weeks; Can’t be used > 34 weeks
- Short term measure- < 48 hrs
When and why are antenatal steroids given?
Develop the fetal lungs and reduce respiratory destress syndrome after delivery
Used in women with suspected preterm labour of babies less than 36 weeks gestation
What is IV magnesium sulphate given for? Why is close monitoring required?
Protect the fetal brain during premature delivery. Reduces the risk and severity of cerebral palsy.
Given as a bolus within 24 hrs of delivery of preterm babies of <34 weeks gestation.
Infusion for up to 24hrs after birth
Close monitoring for toxicity required- 4 hourly- tendon reflexes (patella)
Signs of toxicity- reduced RR, reduced BP, absent reflex
What is induction of labour?
Use of medication to stimulate the onset of labour
Occurs in ~20% pregnancies
When is induction of labour offered?
Between 41 and 42 weeks gestation
Indications
- Prelabour premature rupture of membranes where labour does not start
- Prolonged pregnancy eg 1-2weeks after EDD
- FGR
- Diabetic mother > 38 weeks
- Pre-eclampsia
- Rhesus incompatibility
- Obstetric cholestasis
- Intrauterine fetal death
What is the Bishop Score?
Scoring system used to determine whether to induce labour
- A score of < 5 indicates that labour is unlikely to start without induction
- A score of ≥ 8 indicates that the cervix is ripe, or ‘favourable’ - there is a high chance of spontaneous labour, or response to interventions made to induce labour
- Components: cervical nposition, cervical dilation, cervical effacement, cervical consistecy, fetal station
- PDECS
What are the options for induction of labour?
- Membrane sweep- should induce labour within 48 hrs, typically offered from 40 weeks in ANC
- Vaginal prostaglandins E2 (dinoprostone) (PGE2)- NICE say this is the preferred method of induction unless there are specific contraidnicates/ reasons to not use
- Cervical ripening ballon (CRB)- passed through endocervical canal and gently inflated to dilate cervic
- Artifical rupture of membranes - amniotomy
- Maternal oxytocin infusion
- Oral mifepristone (anti-progesterone) plus misoprostol- intrauterine death
What is a membrane sweep?
Inserting a finger into the cervix to stimlate the cervix: finger passing through the cervix to rotate against the wall of the uterus, to separate the chorionic membrane from the decidua
Can be performed in antenatal clinic by midwife and if successful should produce the onset of labour within 48 hours
Seen as an adjunct to the full induction of labour.
Used from 40 weeks gestation to attempt to initiate labour in women over their EDD
What does a vaginal prostaglandin E2 (dinoprostone) involve?
Inserting a gel, tablet (Prostin) or pessary (propess) into the vagina.
The pessary is similar to a tampon, slowly releasing local prostaglandins over 24 hours.
Stimulates uterus and causes the onset of labour.
Usually done in the hospital setting so the woman can be monitored before being allowed home to await the full onset of labour.
What is a cervical ripening ballon?
Silicone ballow which is inserted into the cervix and gently inflated to dilate the cervix
Used ias an alternative where vaginal prostaglandins are not preferred, usually in women with a previous C-section or where vaginal prostaglandins have failed or multiparous women (para 3)
What is the artificial rupture of membranes?
With an oxytocin infusion can also be used to induce labour.
This is used there there are reasons not to use vaginal prostaglandins, can be used also to progress the induction of labour after vaginal prostaglandins have been used
What are the two means for monitoring during the induction of labour?
Cartiotocography (CTG) to assess the fetal heart rate and uterine contractions before the induction of labour
Bishop score before and during the induction of labour to monitor the progress
What is the ongoing management of induction of labour? Discuss options when there is slow/ no progress
Most women will give birth within 24 hours of the start of induction of labour
The options where there is slow or no progress include:
- Further vaginal prostaglandins
- Artificial rupture of membranes and oxytocin infusion
- Cervical ripening balloon (CRB)
- Elective caesarean section
What is the main complication of using vaginal prostaglandins to induce labour? How is it managed and what are the potential consequences
Uterine hyperstimulation - causing fetal distress and compromise
Refers to prolonged and frequent uterine contractions - sometimes called tachysystole
Potential consequences-
- Itermittent interruption of blood flow to the intervillous space over time may result in fetal hypoxemia and acidemia
- Emergency CS
- Uterine rupture (rare)
Mx-
- Remove vaginal prostaglandins or stop oxytocin infusion
- Tocolysis with terbutaline
What is the criteria for uterine hyperstimuation?
Varies between guidelines, two criteria often used are:
- Individual uterine contractions lasting more than 2 minutes in duration
- More than 5 uterine contractions every 10 minutes
What does cartiotocography do?
Measures the fetal heart rate and the contractions of the uterus
What is oxytocin? Describe its use in obs and gynae?
Hormone secreted by the posterior pituitary gland (produced in the hypothalamus). Stimulates ripening of the cervix & contractions of uterus during labour and delivery, plays a role in lactation during BF
Role of infusions
- Induce labour
- Progress labour
- Improve frequency & strength of uterine contractions (most receptors in myometrium)
- Best used where membranes have ruptured, whether spontaneously or after amniotomy
- Has been shown to increase cervical prostaglandin levels
Syntocinon is a synthetic version of oxytocin that is used in the active management of third stage of labour. It stimulates the contraction of the uterus reducing the risk of postpartum haemorrhage. It is also used to induce labour.
What is ergometrine? Side effects?
Medication to stimulate smooth muscle contraction, both in uterus and blood vessels
Derived from ergot plants
Useful for delivery of the placenta and reduces post partum bleeding
- used as an alternative to oxytocin in the active management of third stage of labour. By constricting vascular smooth muscle of the uterus it can decrease blood loss.
- (Only used after delivery of baby, not in 1st/2nd stage)
- S/E: htn, diarrhoea, vomiting, angina (coronary artery spasm)
- Avoid in eclampsia, used in caution in pts with htn
What is syntometrine? When is it used?
Combination drug containing oxytocin (syntocinon) and ergometrine
Used for prevention/treament of PPH
Role of prostaglandins during labour?
Dinoprostone- prostaglandin E2 used for induction of labour
Comes as vaginal pessary/ tablet/ gel
Prostaglandins stimulate uterine contraction and ripen cervix prior to delivery
When are NSAIDs used in gynaecology? Why should they be avoided in pregnancy?
Treating dysmenorrhoea (painful periods) as they reduce painful cramping (e.g. ibruprofen and mefenamic acid)
- NSAIDs inhibit action of prostaglandins
- Prostaglandins act as vasodilators and lower bp
- NSAIDs can increase BP
What is misoprostol?
Prostalandin analogue (binds to prostaglandin receptors and activates them)
Mifepristone is used in combination with misoprostol to terminate pregnancies.
Also used for induction of labour after intrauterine fetal death
What type of drug is nifedipine? Uses in pregnancy?
CCB which acts to reduce smooth muscle contraction in blood vessels and the uterus
2 uses in pregnancy- reduce bp in htn and pre-eclampsia; tocolysis in premature labour where it suppresses uterine activity and delays onset of labour
What is terbutaline?
Beta-2-agonist similar to salbutamol
Acts on s.m. of uterus to suppress contractions
Used for tocolysis in uterine hyperstimulation
What is carboprost?
Synthetic prostaglandin analogue - stimulating uterine contraction
Given as deep IM injection in PPH where ergometrine and oxytocin have been inadequate
Avoid/ caution in asthma- can cause life-threatening attack
What is tranexamic acid?
Antifibrinolytic which reduces bleeding (binds to fibrinogen and prevents it from converting to plasmin)
Used in prevention and treatment of PPH
What is progress in labour influenced by?
The 3 Ps:
Power (uterine contractions)
Passenger (size, presentation and position of the baby)
Passage (the shape and size of the pelvis and soft tissues)
What suggests delay in the 1st stage of labour? What are the main causes?
Less than 2cm of cervical dilatation in 4 hours
Slowing of progress in a multiparous women
Causes:
- Most common: inefficient uterine actions (power)
- Malposition/ malpresentation of fetus (passenger)
- Inadequate pelvis (passage)
- Or, a combo of the above
What is the second stage of labour?
From 10cm dilation of the cervix to delivery of the baby - success depends on: the three Ps
How is delay in the second stage classified?
When the active second stage (pushing) lasts over:
2 hours in a nulliparous woman
1 hour in a multiparous woman
Factors affecting delay in second stage of labour and how these can be overcome?
- POWER: strength of uterine contractions
- Weak contractions- give oxytocin infusion
- Passenger: size, attitude, lie, presentation
- Passage
- Change positions
- Encouragement
- Analgesia
- Episiotomy
- Instrumental delivery
- CS
What is a delay in the third stage of labour defined as?
More than 30 minutes with active management
More than 60 minutes with physiological management
What does active management of the third stage of labour involve?
- Intramuscular syntometrine (ergometrine 0.5mg + oxytocin 5IU) or oxytocin 10IU IM (this is preferred by NICE due to fewer side effects) is given as the anterior shoulder of baby is born
- A dish is placed at the introitus to collect the placenta and any blood loss, and the left hand is placed on the abdomen over the uterine fundus.
- As the uterus contracts to 20-wk size, the placenta separates from the uterus through the spongy layer of the decidua basalis.
- The uterus will then feel globular and firmer, the cord will lengthen, and there is often a trickle of fresh blood (separation bleeding).
- Controlled cord traction (CCT)- Applied with the right hand, whilst supporting the fundus with the left hand (Brandt–Andrew’s technique)
(exclude multiple pregnancy before giving uterotonixcs)
Physiological mx-
- No Syntometrine® or oxytocin is given.
- Cord is allowed to stop pulsating before it is clamped and cut. NICE (2014) recommends that the cord should not be clamped at least for 1min, unless the baby’s heart rate is <60bpm and not picking up.
- Currently equipment are available that can be kept by the side of the mother to help resuscitation with the cord intact.
- Cord should be clamped before the end of 5mins.
- The placenta is delivered by maternal effort alone.
What are the management options for failure to progress in labour?
Amniotomy, also known as artificial rupture of membranes (ARM) for women with intact membranes
Oxytocin infusion
Instrumental delivery
Caesarean section
What is used first line in failure to progress during labour?
Oxytocin to stimulate contractions during labour - started at a low rate and then titrated up at intervals of at least 30 minutes as required
When using oxytocin in labour, what is the number of contractions to aim for?
4-5 contractions per 10 minutes (too may can cause fetal compromise as it doesn’t have the time to recover between contractions)
What can help with managing pain in labour (without medications)
Understanding what to expect
Having good support
Being in a relaxed environment
Changing position to stay comfortable
Controlled breathing
Water births may help some women
TENS machines may be useful in the early stages of labour
What pain relief is used in labour?
Paracetamol (codeine may be added for additional effect - NSAIDs are avoided)
Gas and Air (entonox) - mixture of 50% nitrous oxide and 50% oxygen to give short term pain relief during contraction
- Can cause lightheadedness, sleepiness, nausea
IM pethidine or diamorphine
- Opioids
- May help with anxiety & distress
Pt controlled analgesia- remifentanil
- Careful monitoring, input from anaesthetist
- Access to naloxone for respiratory depression
- Access to atropine for bradycardia
Epidural
- Small catheter into epidural space in lower back
- Local anaesthetic medications infused through into the epidural space here they diffuse to the surrounding tissues and through to the spinal cord where they have an analgesic effect
- Levobupivacaine, bupivacaine, usually mixed w/ fentanyl
- Adverse effects: headache after insertion, hypotension, motor weakness in legs (assessment urgently by anaesthetist to see if the epidural is in the correct place not the SA space), nerve damage, prolonged 2nd stage, increased probability of instrumental delivery
What is cord prolapse?
When the umbilical cord descends nelow the presenting part of the fetus and through the cervix, into the vagina
Occurs in 1/500 deliveries
Left untreated, this can lead to compression of the cord or cord spasm, which can cause fetal hypoxia and eventually irreversible damage or death.
Describe some risk factors for cord prolapse
Most significant- Fetus is in an abnormal lie after 37 weeks gestation (unstable, transverse or oblique)
Others-
- Prematurity
- Multiparity
- Polyhydramnios
- Twin pregnancy
- Artificial rupture of membranes
When should an umbilical cord prolapse be suspected and how is it diagnosed?
Signs of fetal distress on the CTG - fetal HR becomes abnormal
Diagnosed with vaginal examination with speculum confirming diagnosis- cord may be palpable vaginally or visible beyond the level of the introitus (vaginal opening)
What is the management for a prolapsed umbilical cord?
Emergency C-Section recommended; instrumental vaginal may be possible if the cervix is fully dilates and the head is low
Cord should be kept warm and wet and have minimal handling as this causes vasospasm
the patient is asked to go on ‘all fours’ until preparations for an immediate caesarian section have been carried out
-Alternative position: left lateral position
Tocolytics to reduce uterine contractions
Retrofilling the bladder with 500-700ml of saline may be helpful as it gently elevates the presenting part
If treated early, fetal mortality in cord prolapse is low. Incidence has been reduced by the increase in caesarian sections being used in breech presentations.
What is shoulder dystocia?
When anterior shoulder of the baby becomes stuck behind the pubic symphysis of the pelvis after the head has been delivered
Obstetric emergency
Risk factors for shoulder dystocia?
Antenatal
- Macrosomia secondary to gestational diabetes
- High maternal BMI >30 and excessive weight gain in pregnancy
- Diabetes mellitus
- Post-term pregnancy
- Previous hx of shoulder dystocia
Intrapartum
- Prolonged labour - lack of progress in late 1st or 2nd stage labour
- Instrumental vaginal delivery (esp. rotational deliveries)
How does shoulder dystocia present?
- Usually the anterior shoulder is impacted against the symphysis pubis, often due to the failure of internal rotation of the shoulders
- Fetal deterioration is rapid, often without cord acidosis, largely due to cord compression and trauma.
What is the turtle neck sign?
Where the head is delivered but then retracts back into the vagina
What are the managment options of shoulder dystocia?
Get help (incl anaesthetics and paediatrics)
Episiotomy
McRoberts manoeuvre hyperflexion of the mother at the hip (bringing knees to abdomen) providing a posterior pelvic tilt lifting the pubic symphysis up and out of the way
Pressure to the anterior shoulder = pressing on the suprapubic region, putting pressure on the posterior aspect of the baby’s anterior shoulder to encourage it under pubic symphysis
Rubins manoeuvre = reaching into vagina, putting pressure on the posterior aspect of the baby’s anterior shoulder
Wood’s screw manoeuvre = performed during a Rubin’s manoeuvre - other hand is used to put pressure on the anterior aspect of the posterior shoulder - to rotate the baby, reverse motion can be tried
Zavanelli manoeuvre pushing the baby’s head back into the vagina so it can be delivered by emergency C-section
Pnemonic HELPERR
- H Call for help (including additional midwife, senior obstetrician, neonatologist, anaesthetist).
- E Episiotomy—remember shoulder dystocia is a bony problem, but an episiotomy may help with internal manoeuvres.
- L Legs into McRoberts’ (hyperflexed at hips with thighs abducted and externally rotated).
- P Suprapubic pressure applied to posterior aspect of anterior shoulder (must know which side fetal back is on) to dislodge it from under symphysis pubis; if continuous pressure fails, a rocking movement may be tried.
- E Enter pelvis for internal manoeuvres, which include:
- pressure exerted on the posterior aspect of anterior shoulder to adduct and rotate the shoulders to the larger oblique diameter (Rubin II)
- if this fails combine it with pressure on the anterior aspect of the posterior shoulder (Woods’ screw)
- if this fails, reversing manoeuvre may be tried with pressure on the anterior aspect of anterior shoulder and posterior aspect of posterior shoulder in opposite direction (reverse Woods’ screw).
- R Release of posterior arm by flexing elbow, getting hold of fetal hand, and sweeping fetal arm across chest and face to release posterior shoulder.
- R Roll over to ‘all fours’ may help aid delivery by the changes brought about in the pelvic dimensions (Gaskin manoeuvre).
What are the key complications of shoulder dystocia?
Fetal hypoxia (and subsequent cerebral palsy)
Brachial plexus injury and Erb’s palsy
Perineal tears
Postpartum haemorrhage
What does an instrumental delivery refer to?
Using a ventouse suction cup or forceps (about 10% of births are assisted with an instrumental delivery)
What is given prophylactically after an instrumental delivery?
Single dose of co-amoxiclav
What are some indications for an instrumental delivery?
Failure to progress
Fetal distress
Maternal exhaustion
Control of the head in various fetal positions
What are the risks to the mother for an instrumental delivery?
Postpartum haemorrhage
Episiotomy
Perineal tears
Injury to the anal sphincter
Incontinence of the bladder or bowel
Nerve injury (obturator or femoral nerve)
What are the key risks to the baby during an instrumental delivery?
Cephalohaematoma with ventouse
Facial nerve palsy with forceps
What are the serious risks to the baby during an instrumental delivery?
Subgaleal haemorrhage (most dangerous)
Intracranial haemorrhage
Skull fracture
Spinal cord injury
What is a ventouse?
A suction cup on a cord placed on the baby’s head
What is the main complication when using a ventouse?
Cephalohaematoma (collection of blood between the skull and periosteum)
What is the main complication of using forceps during delivery?
Facial nerve palsy with facial paralysis on one side
Bruises on the babys face
Fat necrosis leading to hardened lumps which resolve spontaneously over time
What nerve injury can there be in the mother following an instrumental delivery?
Femoral nerve - compressed against the inguinal canal during a forceps delivery - causing weakness of knee extension, loss of the patella reflex and numbness of the anterior thigh and medial lower leg
Obturator nerve - compressed by forceps or by fetal head during normal delivery - weakness of hip adduction and rotation and numbness of the medial thigh
When are perineal tears more common?
First births (nulliparity)
Large babies (over 4kg)
Shoulder dystocia
Asian ethnicity
Occipito-posterior position
Instrumental deliveries
What are the four degrees of perineal tears?
First-degree – superficial damage with no muscle involvement, no repair required, simple vaginal mucosa torn
Second-degree – including the perineal muscles, but not affecting the anal sphincter, require suturing on the ward by a suitably experienced midwife or clinician
Third-degree – including the anal sphincter complex (EAS and IAS), but not affecting the rectal mucosa
- 3a: less than 50% of EAS thickness torn
- 3b: more than 50% of EAS thickness torn
- 3c: IAS torn
- Require repair in theatre
Fourth-degree – tear to anal sphincter complex (EAS and IAS) and including the rectal mucosa
- Require repair in theatre
What are the subcategories of third-degree tears?
3A – less than 50% of the external anal sphincter affected
3B – more than 50% of the external anal sphincter affected
3C – external and internal anal sphincter affected
What is the management of a first degree tear?
Do not require any sutures normally
What is the managment of a perineal tear larger than first degree?
Requires sutures
What are the additional measure taken to reduce the risk of complications in perineal tears?
Broad-spectrum antibiotics to reduce the risk of infection
Laxatives to reduce the risk of constipation and wound dehiscence
Physiotherapy to reduce the risk and severity of incontinence
Followup to monitor for longstanding complications
What are the short term complications of a perineal tear repair?
Pain
Infection
Bleeding
Wound dehiscence or wound breakdown
What are the lasting complications of a perineal tear?
Urinary incontinence
Anal incontinence and altered bowel habit (third and fourth-degree tears)
Fistula between the vagina and bowel (rare)
Sexual dysfunction and dyspareunia (painful sex)
Psychological and mental health consequences
What is an episiotomy?
Where the obstetrician / midwife cuts the perineum before the baby is delivered - done in anticipation of needing more room e.g. forceps delivery - performed under local anaesthetic
Cut is made at around 45 degrees diagnonally from the opening of the vaginal down and out to avoid damaging the anal sphincter - called a mediolateral episiotomy
Cut is sutured after delivery
What is a perineal massage?
Method for reducing the risks of perineal tear - massaging the skin between the vagina and anus (perineum) - in a structured way from 34 weeks onwards to stretch and prepare the tissues for delivery
What are the two options for the third stage of labour?
Physiological management
Active management
What is physiological management?
Placenta is delivered by maternal effort without medication or cord traction
No Syntometrine or oxytocin is given.
- Cord should be clamped before the end of 5mins.
- The placenta is delivered by maternal effort alone.
What is active management of the third stage?
Dose of intramuscular oxytocin (to help uterus contract)
Traction to the umbilical cord to guide the placenta out (controlled cord traction)
Clamping and cutting of the cord
Why is active management of the third stage sometimes used? What are the adverse effects?
Reduces risk of bleeding
Reduce rates of PPH >1000mL
Reduce mean blood loss and postnatal anaemia
Reduce length of third stage
Reduce need of blood transufsions
Adverse effects: nausea and vomiting, headache
When is active management initiated?
routinely offered to reduce PPH
Haemorrhage
More than 60 min delay in delivery of the placenta (prolonged third stage)
What are the steps in active management of the third stage?
IM dose of oxytocin after delivery of the baby
Cord is clamped and cut within 5 mins of birth (delay of 1-3 mins)
Abdo palpated to assess for a uterine contraction before delivery of the placenta
Controlled cord traction is applied (stopping if resistance)
Other hand presses the uterus upwards to prevent uterine prolapse
After delivery the uterus is massaged until it is contracted and firm - placenta is examined to ensure it is complete
What is Postpartum haemorrhage (PPH)?
Bleeding after delivery of the baby and placenta- needs to be a loss of:
- 500ml after a vaginal delivery
- 1000ml after a caesarean section
What are the different categories of PPH?
Minor PPH – under 1000ml blood loss
Major PPH – over 1000ml blood loss
Moderate PPH – 1000 – 2000ml blood loss
Severe PPH – over 2000ml blood loss
What is the difference between primary and secondary PPH?
Primary PPH: bleeding within 24 hours of birth
Secondary PPH: from 24 hours to 12 weeks after birth
What are the four causes of PPH?
T – Tone (uterine atony – the most common cause)- soft boggy uterus
T – Trauma (e.g. perineal tear)- laceration or uterine inversion- re-place inverted uterus
T – Tissue (retained placenta)- or clot
T – Thrombin (bleeding disorder)- blood not clotting, observe clotting, check coag studies, replace clotting factors, plts, supply FFP
What are the risk factors for PPH?
Previous PPH
Multiple pregnancy
Obesity
Large baby
Failure to progress in the second stage of labour
Prolonged third stage
Pre-eclampsia
Placenta accreta
Retained placenta
Instrumental delivery
CS
General anaesthesia
Episiotomy or perineal tear
What are the preventative measures for 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
How to stabilise a woman with PPH?
Resuscitation with an ABCDE approach
Lie the woman flat, keep her warm and communicate with her and the partner
Insert two large-bore cannulas
Bloods for FBC, U&E and clotting screen
Group and cross match 4 units
Warmed IV fluid and blood resuscitation as required
Oxygen (regardless of saturations)
Fresh frozen plasma is used where there are clotting abnormalities or after 4 units of blood transfusion
How are severe cases of PPH managed?
By activating the major haemorrhage protocol giving rapid access to 4 units of crossmatched or O negative blood
What are the mechanical options for stopping PPH?
Rubbing the uterus through the abdomen to stimulates a uterine contraction (referred to as “rubbing up the fundus”)
Catheterisation (bladder distention prevents uterus contractions)
What are the medical options for stopping PPH?
Oxytocin (slow injection IM or IV 10 IU followed by continuous infusion 40 IU over 4 hrs)
Ergometrine (intravenous or intramuscular) stimulates smooth muscle contraction (contraindicated in hypertension)- 500mcg IM
Carboprost (intramuscular) is a prostaglandin analogue and stimulates uterine contraction (caution in asthma) -250mcg every 15 mins, up to 8 doses
Misoprostol (sublingual) is also a prostaglandin analogue and stimulates uterine contraction - 800mcg PR
Tranexamic acid (intravenous) is an antifibrinolytic that reduces bleeding - 1gram IV give early (slow), 2nd dose after 30mins if PPH persists- slow dose 1g
What are some surgical treatment options for PPH?
Intrauterine balloon tamponade – inserting an inflatable balloon into the uterus to press against the bleeding
B-Lynch suture – putting a suture around the uterus to compress it
Uterine artery ligation – ligation of one or more of the arteries supplying the uterus to reduce the blood flow
Hysterectomy is the “last resort” but will stop the bleeding and may save the woman’s life
What is secondary postpartum haemorrhage likely to be due to?
Retained products of conception (RPOC)
Infection (i.e. endometritis).
What are the investigations for secondary PPH?
Ultrasound for retained products of conception
Endocervical and high vaginal swabs for infection
What are the management options for secondary PPH?
Surgical evacuation of retained products of conception
Antibiotics for infection
What anaesthetic is an elective caesarean performed under?
Spinal anaesthetic
What are some indications for an elective caesarean?
Previous caesarean
Symptomatic after a previous significant perineal tear
Placenta praevia
Vasa praevia
Breech presentation
Multiple pregnancy
Uncontrolled HIV infection
Cervical cancer
What are the four categories of emergency caesarean?
Category 1: There is an immediate threat to the life of the mother or baby. Decision to delivery time is 30 minutes.
- Placental abruption with abnormal FHR or uterine irritability
- Cord prolapse
- Scar rupture
- Prolonged bradycardia
- Scalp pH <7.2
Category 2: 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.
- Failure to progress with pathological CTG
Category 3: Delivery is required, but mother and baby are stable. (scheduled CS)
- Severe pre-eclampsia
- IUGR with poor fetal function tests
- Failured induction of labour
Category 4: Elective CS- usually after 39 wks unless indicated, as the risk of respiratory morbidity (transient tachypnoea of the newborn) is increased at lower gestational ages
- Term singleton breech
- Twin pregnancy with non-cephalic 1st twin
- Maternal HIV
- Primary genital herpes in 3rd trimester
- Placenta praevia
- Previous hysterotomy or classic CS
What are the two possible incisions in a caesarean?
Pfannenstiel incision is a curved incision two fingers width above the pubic symphysis- superior cosmetic result
Joel-cohen incision is a straight incision that is slightly higher (this is the recommended incision)- allows quicker entry into the abdomen
What are the layers of the abdomen which need dissecting during a caesarean?
- Skin
- Subcutaneous tissue
- Fascia / rectus sheath (the aponeurosis of the transversus abdominis and external and internal oblique muscles)
- Rectus abdominis muscles (separated vertically)
- Peritoneum
- Vesicouterine peritoneum (and bladder) – the bladder is separated from the uterus with a bladder flap
- Uterus (perimetrium, myometrium and endometrium)
- Amniotic sac
What is involved in a spinal anaesthetic?
An injection of a local anaesthetic (such as lidocaine) into the CSF at the lower back
Blocking the nerves from the abdomen downwards
What are some measures to reduce the risk before a caesarean section?
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
Why are H2 receptor antagonists / PPI given before a caesarean section?
To reduce the risk of aspiration pneumonitis caused by acid reflux and aspiration during prolonged period of lying flat
What are some general surgical risks during a caesarean?
Bleeding
Infection
Pain
Venous thromboembolism
What are some complication in the post partum period after a C-Section?
Postpartum haemorrhage
Wound infection
Wound dehiscence
Endometritis
What local structures can be damaged during a C-Section?
Ureter
Bladder
Bowel
Blood vessels
What effect does C-Sections have on the abdominal organs?
Ileus
Adhesions
Hernias
What effect do C-Sections have on future pregnancies?
Increased risk of repeat caesarean
Increased risk of uterine rupture
Increased risk of placenta praevia
Increased risk of stillbirth
What are the effects of a C-section on the baby?
Risk of lacerations (about 2%)
Increased incidence of transient tachypnoea of the newborn
When is it possible to have a vaginal birth after caesarean (VBAC)?
Possible, provided the cause of the caesarean is unlikely to recur.
Assessment of likelihood of success should be made in each case
What is the success rate of a VBAC?
75%
What are some contraindications to a VBAC?
Previous uterine rupture
Classical caesarean scar (a vertical incision)
Other usual contraindications to vaginal delivery (e.g. placenta praevia)
After a caesarean what prophylaxis should the woman be started on?
Early mobilisation
Anti-embolism stockings or intermittent pneumatic compression of the legs
Low molecular weight heparin (e.g. enoxaparin)
What is Sepsis?
Condition where body launches a large immune response to infection causing systemic inflammation and affecting the functioning of the organs of the body
Significant cause of maternal death
What is severe sepsis?
When sepsis results in organ dysfunction such as hypoxia, oliguria or raised lactate
What is septic shock?
When arterial blood pressure drops and results in organ hypo-perfusion
What are two key causes of spesis in pregnancy?
Chorioamnionitis- infection of chorioamniotic membranes and amniotic fluid, usually occurs in later pregnancy and labour
Urinary tract infections
What are all patients who are admittted to the maternity inpatient unit have monitoring documented on?
MEOWS chart - maternity early obstetric warning system
What are the non-specific signs of sepsis?
Fever
Tachycardia
Raised respiratory rate (often an early sign)
Reduced oxygen saturations
Low blood pressure
Altered consciousness
Reduced urine output
Raised white blood cells on a full blood count
Evidence of fetal compromise on a CTG
What are some investigations for suspected sepsis?
Full blood count to assess cell count including white cells and neutrophils
U&Es to assess kidney function and for acute kidney injury
LFTs to assess liver function and as a possible source of infection (e.g. acute cholecystitis)
CRP to assess inflammation
Clotting to assess for disseminated intravascular coagulopathy (DIC)
Blood cultures to assess for bacteraemia
Blood gas to assess lactate, pH and glucose
How to manage maternal sepsis?
- Follow local guidelines
- Senior obstetricians and midwives involved early
- Continuous maternal and fetal monitoring
- Early delivery (C-Section where there is fetal distress)
- General anaesthesia for maternal sepsis
- Antibiotics guided by local guidelines
- Example regimes of abx: piperacillin and tazobactam (tazocin) plus gentamicin, or amoxicillin, clindamycin and gentamicin
What is the 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
What is amniotic fluid embolisation?
Amniotic fluid passes into the mothers blood rare (2 per 100,000 births) but severe condition, usually occuring around delivery
What is the problem with amniotic fluid embolisation?
Amniotic fluid contains fetal tissue causing an immune reaction from the mother, leading to a systemic illness - more similarities to anaphylaxis than VTE - mortality is around 20% or above
What are the risk factors for amniotic fluid embolus?
Increasing maternal age
Induction of labour
Caesarean section
Multiple pregnancy
How does amniotic fluid embolus present?
Similarly to sepsis, PE or anaphylaxis:
Shortness of breath
Hypoxia
Hypotension
Coagulopathy
Haemorrhage
Tachycardia
Confusion
Seizures
Cardiac arrest
What is the overall managment of amniotic fluid embolisation?
Supportive - no specific treatments
What are the steps in amniotic fluid embolus management?
Medical emergency
Input of experienced obstetricians
A – Airway: Secure the airway
B – Breathing: Provide oxygen for hypoxia
C – Circulation: IV fluids to treat hypotension and blood transfusion in haemorrhage
D – Disability: Treat seizures and consider other neurological deficits
E – Exposure
What is uterine rupture?
Complication of labour, myometrium ruptures
Incomplete- uterine dehiscence- the uterine seorsa (perimetrium) surrounding the uterus remains intact
Complete rupture- the serosa ruptures along with the myometrium and the contents of the uterus are released into the peritoneal cavity
What is the consequence of uterine rupture?
Significant bleeding where the baby may be released from the uterus into the peritoneal cavity (high morbidity and mortality for baby and mother)
What are the main risk factors for uterine rupture?
Previous caesarean section as the scar is a point of weakness
- the scar becomes a point of weakness, may rupture with XS pressure eg XS stimulation by oxytocin
VBAC
Previous uterine surgery
Increased BMI
High parity
Increased age
Induction of labour
Use of oxytocin to stimulate contractions
How does a uterine rupture present?
Acutely unwell mother and abnormal CTG - may occur with induction or augmentation of labour:
Abdominal pain
Vaginal bleeding
Ceasing of uterine contractions
Hypotension
Tachycardia
Collapse
What is the management of a uterine rupture?
Obstetric emergency - resuscitation and transfusion may be necessary
Emergency caesarean section to remove the baby, stop any bleeding and repair or remove the uterus
What is uterine inversion?
Rare complication of birth where the fundus of the uterus drops down through the uterine cavity and cervix, turning the uterus inside out
Life threatening
What is incomplete uterine inversion (partial inversion) ?
Fundus descends inside the uterus or vagina but not as far as the introitus (opening of the vagina)
What is complete uterine inversion?
Uterus descends through the vagina to the introitus
What may uterine inversion be the result of?
Pulling too hard on the umbilical cord during active management of the third stage of labour
How does uterine inversion present?
Large post partum haemorrhage (maternal shock or collapse)
Incomplete inversion may be felt with manual vaginal examination with a complete uterine inversion, the uterus may be seen at the introitus of the vagina
What are the three options for treating uterine inversion?
Johnson manoeuvre
- Using a hand to push the fundus back up into the abdomen and the correct position
- The whole hand and most of the forearm will be inserted into the vagina to return the fundus to the correct position
- Held in place for several mins
- Meds used to create uterine contraction (oxytocin)
Hydrostatic methods
- Where the Johnson manoeuvre fails
- Filling the vagina with fluid to inflate the uterus back into the normal position
Requires a tight seal at the entrance of the vagina
Surgery
- Laparotomy and return uterus to normal position
Women in labour with fever > 38C should receive which abx
Royal college guidelines state woman with pyrexia during labour should receive GBS prophylaxis, which is benzylpenicillin. Vancomycin should be used if there is a known severe penicillin allergy. Erythromycin is used in woman with preterm prelabour rupture of membranes (PPROM).
State some risk factors for GBS infection in neonate?
- prematurity
- prolonged rupture of the membranes
- previous sibling GBS infection
- maternal pyrexia e.g. secondary to chorioamnionitis
What is a CTG used for, how does it work?
Used during pregnancy/ labour to monitor fetal heart rate and uterine contractions
- Fetal heart rate: transducer above fetal heart, contains doppler ultrasound
- Uterine contractions: transducer at fundus of uterus, assesses tension of abdominal wall of mother providing an indirect indication of intrauterine pressure
What are some reasons a pregnancy could be considered high risk?
Maternal medical illness
- Gestational diabetes
- Hypertension
- Asthma
Obstetric complications
- Multiple gestation
- Post-date gestation
- Previous cesarean section
- Intrauterine growth restriction
- Premature rupture of membranes
- Congenital malformations
- Oxytocin induction/augmentation of labour
- Pre-eclampsia
Other risk factors
- Absence of prenatal care
- Smoking
- Drug abuse
What does baseline rate refer to when interprating a CTG? What is normal?
The baseline rate is the average heart rate of the fetus within a 10-minute window.
A normal fetal heart rate is between 110-160 bpm.
Define fetal tachycardia and what causes it?
Baseline HR > 160
- Fetal hypoxia
- Chorioamnionitis
- Hyperthyroidism
- Fetal or maternal anaemia
- Fetal tachyarrhythmia
Define fetal bradycardia and what causes it?
Baseline HR < 100bpm
It is common to have a baseline heart rate of between 100-120 bpm in the following situations:
- Postdate gestation
- Occiput posterior or transverse presentations
Severe prolonged bradycardia (less than 80 bpm for more than 3 minutes) indicates severe hypoxia.
Causes of prolonged severe bradycardia include:
- Prolonged cord compression
- Cord prolapse
- Epidural and spinal anaesthesia
- Maternal seizures
- Rapid fetal descent
What does baseline variability refer to when interpreting a CTG? Why does it occur?
- Baseline variability refers to the variation of fetal heart rate from one beat to the next.
- Variability occurs as a result of the interaction between the nervous system, chemoreceptors, baroreceptors and cardiac responsiveness.
- It is, therefore, a good indicator of how healthy a fetus is at that particular moment in time, as a healthy fetus will constantly be adapting its heart rate in response to changes in its environment.
- Normal variability indicates an intact neurological system in the fetus.
- Normal variability is between 5-25 bpm.
- To calculate variability you need to assess how much the peaks and troughs of the heart rate deviate from the baseline rate (in bpm)
- Variability can be categorised as reassuring, non-reassuring or abnormal
- Reassuring: 5 – 25 bpm
- Non-reassuring:
- less than 5 bpm for between 30-50 minutes
- more than 25 bpm for 15-25 minutes
- Abnormal:
- less than 5 bpm for more than 50 minutes
- more than 25 bpm for more than 25 minutes
- sinusoidal
What can cause reduced variability on a CTG?
- Fetal sleeping: this should last no longer than 40 minutes (this is the most common cause)
- Fetal acidosis (due to hypoxia): more likely if late decelerations are also present
- Fetal tachycardia
- Drugs: opiates, benzodiazepines, methyldopa and magnesium sulphate
- Prematurity: variability is reduced at earlier gestation (<28 weeks)
- Congenital heart abnormalities
What are accelerations and decelerations on a CTG?
Accelerations are an abrupt increase in the baseline fetal heart rate of greater than 15 bpm for greater than 15 seconds
- Their presence is reassuring
- Accelerations occurring alongside uterien contractions is a sign of a healthy fetus
Decelerations are an abrupt decrease in the baseline fetal heart rate of greater than 15 bpm for greater than 15 seconds.
What are the types of decelerations on a CTG and what do they mean?
Early deceleration
- start when the uterine contraction begin
- recover when uterine contraction stops
- due to increased fetal intracranial pressure causing increased vagal tone, hence quickly resolves once uterine contraction ends and the intracranial pressure reduces
- Physiological NOT pathological
Variable decelerations
- rapid fall in baseline fetal heart rate with a variable recovery phase
- variable in their duration and may not have any relationship to uterine contractions
- most often seen during labour and in patients’ with reduced amniotic fluid volume
- All fetuses experience stress during the labour process, as a result of uterine contractions reducing fetal perfusion. Whilst fetal stress is to be expected during labour, the challenge is to pick up pathological fetal distress
- Variable decelerations are usually caused by umbilical cord compression
- Umbilical vein is occluded first causing acceleration of fetal HR in response
- Then the umbilical artery is occluded causing subsequent rapid deceleration
- When the pressure on the cord is reduced another acceleration occurs and then the baseline HR returns
- The accelerations before and after a variable deceleration are known as the shoulders of deceleration - indicates the fetus is not yet hypoxic and is adapting to the reduced blood flow - if these are not present it can suggest the fetus is becoming hypoxic
- Variable decelerations can resolve if mother changes position
Late deceleration
- begin at the peak of the uterine contraction and recover after the contraction ends
- This type of deceleration indicates there is insufficient blood flow to the uterus and placenta
- As a result, blood flow to the fetus is significantly reduced causing fetal hypoxia and acidosis
- Causes- maternal hypotension, pre-eclampsia, uterine hyperstimulation
Prolonged deceleration
- Defined as a deceleration that lasts more than 2 minutes
- 2-3 mins: non-reassuring
- >3 mins: abnormal
Causes of a sinusoidal pattern on a CTG?
- Severe fetal hypoxia
- Severe fetal anaemia
- Fetal/maternal haemorrhage
What are some concerning characteristics of variable decelerations?
- Lasting more than 60 seconds
- Reduced baseline variability within the deceleration
- Failure to return to baseline
- Biphasic (W) shape
- No shouldering
