Obstetrics 2 Flashcards
Can sodium valproate be used in pregnancy for epilepsy?
NO
___________ are important in maintaining the ductus arteriosus in the fetus and neonate.
Prostaglandins are important in maintaining the ductus arteriosus in the fetus and neonate.
Are NSAIDs used in preganancy?
NSAIDS are generally avoided in pregnancy unless really necessary (e.g. in rheumatoid arthritis). They are particularly avoided in the third trimester, as they can cause premature closure of the ductus arteriosus in the fetus. They can also delay labour
WHat is used for HTN in pregancy
Beta blocker- labetalol
Pregnancy
Beta-blockers can cause:
- Fetal growth restriction
- Hypoglycaemia in the neonate
- Bradycardia in the neonate
ACE Inhibitors and Angiotensin II Receptor Blockers
Can these be used in pregancy?
Medications that block the renin-angiotensin system (ACE inhibitors and ARBs) can cross the placenta and enter the fetus. In the fetus, they mainly affect the kidneys, and reduce the production of urine (and therefore amniotic fluid). The other notably effect is hypocalvaria, which is an incomplete formation of the skull bones.
no
ACE inhibitors and ARBs, when used in pregnancy, can cause:
- Oligohydramnios (reduced amniotic fluid)
- Miscarriage or fetal death
- Hypocalvaria (incomplete formation of the skull bones)
- Renal failure in the neonate
- Hypotension in the neonate
The use of _____ during pregnancy can cause withdrawal symptoms in the neonate after birth. This is called ______ ______ ________ (NAS). NAS presents between 3 – 72 hours after birth with irritability, tachypnoea (fast breathing), high temperatures and poor feeding.
The use of opiates during pregnancy can cause withdrawal symptoms in the neonate after birth. This is called neonatal abstinence syndrome (NAS). NAS presents between 3 – 72 hours after birth with irritability, tachypnoea (fast breathing), high temperatures and poor feeding.
Warfarin may be used in younger patients with ….
Warfarin may be used in younger patients with recurrent venous thrombosis, atrial fibrillation or metallic mechanical heart valves
can you use warfarin in pregancy
no
Warfarin crosses the placenta and is considered teratogenic in pregnancy, therefore it is avoided in pregnant women. Warfarin can cause:
- Fetal loss
- Congenital malformations, particularly craniofacial problems
- Bleeding during pregnancy, postpartum haemorrhage, fetal haemorrhage and intracranial bleeding
The use of sodium valproate in pregnancy causes _____ ____ ______ and _________ ___
The use of sodium valproate in pregnancy causes neural tube defects and developmental delay.
should valproate taken in girls
no
Lithium is particularly avoided in the first trimester, as this is linked with ______ ______ ________. In particular, it is associated with_____ _______, where the tricuspid valve is set lower on the right side of the heart (towards the apex), causing a bigger right atrium and a smaller right ventricle.
Lithium is particularly avoided in the first trimester, as this is linked with congenital cardiac abnormalities. In particular, it is associated with Ebstein’s anomaly, where the tricuspid valve is set lower on the right side of the heart (towards the apex), causing a bigger right atrium and a smaller right ventricle.
Can you use Selective Serotonin Reuptake Inhibitor in preganacy
Selective serotonin reuptake inhibitors (SSRIs) are the most commonly used antidepressants in pregnancy.
. SSRIs can cross the placenta into the fetus. The risks need to be balanced against the benefits of treatment. The risks associated with untreated depression can be very significant.
Women need to be aware of the potential risks of SSRIs in pregnancy:
- First-trimester use has a link with congenital heart defects
- First-trimester use of paroxetine has a stronger link with congenital malformations
- Third-trimester use has a link with persistent pulmonary hypertension in the neonate
- Neonates can experience withdrawal symptoms, usually only mild and not requiring medical management
Isotretinoin is a retinoid medication (relating to vitamin A) that is used to treat severe acne
IT can not be used in pregnancy
WHy?
Isotretinoin is highly teratogenic, causing miscarriage and congenital defects. Women need very reliable contraception before, during and for one month after taking isotretinoin.
Name the medication that should not be used in pregnancy
Non-Steroidal Anti-Inflammatory Drugs
Beta-Blockers- except labetolol
ACE Inhibitors and Angiotensin II Receptor Blockers
Opiates
Warfarin
Sodium Valproate
Lithium
Isotretinoin (Roaccutane)
Selective Serotonin Reuptake Inhibitors?
What is Postpartum Haemorrhag
Postpartum haemorrhage (PPH) refers to bleeding after delivery of the baby and placenta. It is the most common cause of significant obstetric haemorrhage, and a potential cause of maternal death. To be classified as postpartum haemorrhage, there needs to be a loss of:
- 500ml after a vaginal delivery
- 1000ml after a caesarean section
Postpartum Haemorrhage
It can be classified as:
- Minor PPH – under 1000ml blood loss
- Major PPH – over 1000ml blood loss
Major PPH can be further sub-classified as:
- Moderate PPH – 1000 – 2000ml blood loss
- Severe PPH – over 2000ml blood loss
PPH can also be classified as
It can also be categorised as:
- Primary PPH: bleeding within 24 hours of birth
- Secondary PPH: from 24 hours to 12 weeks after birth
There are four causes of postpartum haemorrhage, remembered using the “Four Ts” mnemonic:
- T – Tone (uterine atony – the most common cause)
- T – Trauma (e.g. perineal tear)
- T – Tissue (retained placenta)
- T – Thrombin (bleeding disorder)
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
- General anaesthesia
- Episiotomy or perineal tear
Preventative Measures of PPH
Several measures can reduce the risk and consequences of postpartum haemorrhage:
- 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 to stabilise the patient who has PPH involves:
- 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
PPH
The treatment options for stopping the bleeding can be categorised as:
Mechanical
- Rubbing the uterus through the abdomen to stimulates a uterine contraction (referred to as “rubbing up the fundus”)
- Catheterisation (bladder distention prevents uterus contractions)
Medical
- Oxytocin (slow injection followed by continuous infusion)
- Ergometrine (intravenous or intramuscular) stimulates smooth muscle contraction (contraindicated in hypertension)
- Carboprost (intramuscular) is a prostaglandin analogue and stimulates uterine contraction (caution in asthma)
- Misoprostol (sublingual) is also a prostaglandin analogue and stimulates uterine contraction
- Tranexamic acid (intravenous) is an antifibrinolytic that reduces bleeding
Surgical
- 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
Secondary postpartum haemorrhage is where bleeding occurs from 24 hours to 12 weeks postpartum. This is more likely to be due to retained products of conception (RPOC) or infection (i.e. endometritis).
Secondary Postpartum Haemorrhage
Investigations involve:
Ultrasound for retained products of conception
Endocervical and high vaginal swabs for infection
Secondary Postpartum Haemorrhage
Management depends on the cause:
- Surgical evaluation of retained products of conception
- Antibiotics for infection
Labour and delivery normally occur between 37 and 42 weeks gestation.
There are three stages of labour:
What are they?
- First stage – from the onset of labour (true contractions) until 10cm cervical dilatation
- Second stage – from 10cm cervical dilatation until delivery of the baby
- Third stage – from delivery of the baby until delivery of the placenta
Explain First stage of labour and the three phases it has
The first stage of labour is from the onset of labour (true contractions) until the cervix is fully dilated to 10cm. It involves cervical dilation (opening up) and effacement (getting thinner). The “show” refers to the mucus plug in the cervix, which prevents bacteria from entering the uterus during pregnancy, falling out and creating space for the baby to pass through.
The first stage has three phases:
- Latent phase – from 0 to 3cm dilation of the cervix. This progresses at around 0.5cm per hour. There are irregular contractions.
- Active phase – from 3cm to 7cm dilation of the cervix. This progresses at around 1cm per hour, and there are regular contractions.
- Transition phase – from 7cm to 10cm dilation of the cervix. This progresses at around 1cm per hour, and there are strong and regular contractions.
What is Braxton-Hicks Contractions
Braxton-Hicks contractions are occasional irregular contractions of the uterus. They are usually felt during the second and third trimester. Women can experience temporary and irregular tightening or mild cramping in the abdomen. These are not true contractions, and they do not indicate the onset of labour.
They do not progress or become regular. Staying hydrated and relaxing can help reduce Braxton-Hicks contractions.
Diagnosing the Onset of Labour
The signs of labour are:
- Show (mucus plug from the cervix)
- Rupture of membranes
- Regular, painful contractions
- Dilating cervix on examination
NICE guidelines on intrapartum care (2017) refer to the latent first stage and established list stage.
The latent first stage is when there are both:
The established first stage of labour is when there are both:
The latent first stage is when there are both:
- Painful contractions
- Changes to the cervix, with effacement and dilation up to 4cm
The established first stage of labour is when there are both:
- Regular, painful contractions
- Dilatation of the cervix from 4cm onwards
What the definitions for these phrases
Rupture of membranes (ROM):
Spontaneous rupture of membranes (SROM):
Prelabour rupture of membranes (PROM):
Preterm prelabour rupture of membranes (P‑PROM):
Prolonged rupture of membranes (also PROM):
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.
Prematurity is defined as birth before
37 weeks gestation
From what weeks is resuscitation not considered in babies that do not show signs of life.
23 to 24 weeks,
The World Health Organisation classify prematurity as:
Under 28 weeks: extreme preterm
28 – 32 weeks: very preterm
32 – 37 weeks: moderate to late preterm
What are Prophylaxis of Preterm Labour
Vaginal Progesterone
Cervical Cerclage
What is the role of Progesterone
Progesterone can be given vaginally via gel or pessary as prophylaxis for preterm labour. Progesterone has a role in maintaining pregnancy and preventing labour by decreasing activity of the myometrium and preventing the cervix remodelling in preparation for delivery. This is offered to women with a cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation
What is Cervical Cerclage
Cervical cerclage involves putting a stitch in the cervix to add support and keep it closed. This involves a spinal or general anaesthetic. The stitch is removed when the woman goes into labour or reaches term.
Cervical cerclage is offered to women with a 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).
“Rescue” cervical cerclage may also be offered between 16 and 27 + 6 weeks when there is cervical dilatation without rupture of membranes, to prevent progression and premature delivery.
What is Preterm Prelabour Rupture of Membranes
Preterm prelabour rupture of membranes is where the amniotic sac ruptures, releasing amniotic fluid, before the onset of labour and in a preterm pregnancy (under 37 weeks gestation)
Rupture of membranes can be diagnosed by speculum examination revealing pooling of amniotic fluid in the vagina. No tests are required.
Where there is doubt about the diagnosis, tests can be performed:
- Insulin-like growth factor-binding protein-1 (IGFBP-1) is a protein present in high concentrations in amniotic fluid, which can be tested on vaginal fluid if there is doubt about rupture of membranes
- Placental alpha-microglobin-1 (PAMG-1) is a similar alternative to IGFBP-1
Management for Premature Labour
Prophylactic antibiotics should be given to prevent the development of chorioamnionitis. The NICE guidelines (2019) recommend erythromycin 250mg four times daily for ten days, or until labour is established if within ten days.
Induction of labour may be offered from 34 weeks to initiate the onset of labour.
What is Preterm Labour with Intact Membranes
Preterm labour with intact membranes involves regular painful contraction and cervical dilatation, without rupture of the amniotic sac.
Preterm Labour with Intact Membranes
Diagnosis
Clinical assessment includes a speculum examination to assess for cervical dilatation. The NICE guidelines (2017) recommend:
- 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.
What is an alternative to transvaginal ultrasound
Fetal fibronectin is an alternative test to vaginal ultrasound. Fetal fibronectin is the “glue” between the chorion and the uterus, and is found in the vagina during labour. A result of less than 50 ng/ml is considered negative, and indicates that preterm labour is unlikely.
Management
There are several options for improving the outcomes in 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
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.
Giving the mother corticosteroids helps to develop the fetal lungs and reduce respiratory distress syndrome after delivery. They are used in women with suspected preterm labour of babies less than 36 weeks gestation.
What is an example regime
An example regime would be two doses of intramuscular betamethasone, 24 hours apart.
Giving the mother __ __________ ______ helps protect the fetal brain during premature delivery.
Giving the mother IV magnesium sulfate helps protect the fetal brain during premature delivery
Magnesium Sulfate in pregnancy reduces the risk of?
It reduces the risk and severity of cerebral palsy.
Mothers need close monitoring for magnesium toxicity at least four hourly. This involves close monitoring of observations, as well as tendon reflexes (usually patella reflex). Key signs of toxicity are:
- Reduced respiratory rate
- Reduced blood pressure
- Absent reflexes
Induction of labour (IOL) refers to
the use of medications to stimulate the onset of labour.
Induction of labour can be used where patients go over the due date. IOL is offered between 41 and 42 weeks gestation.
Induction of labour is also offered in situations where it is beneficial to start labour early, such as:
- Prelabour rupture of membranes
- Fetal growth restriction
- Pre-eclampsia
- Obstetric cholestasis
- Existing diabetes
- Intrauterine fetal death
What is Bishop Score
The Bishop score is a scoring system used to determine whether to induce labour.
Bishop Score
Five things are assessed and given a score based on different criteria (minimum score is 0 and maximum is 13):
- Fetal station (scored 0 – 3)
- Cervical position (scored 0 – 2)
- Cervical dilatation (scored 0 – 3)
- Cervical effacement (scored 0 – 3)
- Cervical consistency (scored 0 – 2)
A score of 8 or more predicts a successful induction of labour. A score below this suggests cervical ripening may be required to prepare the cervix.
What are the options for Induction of Labour
Induction of Labour
Vaginal prostaglandin E2 (dinoprostone)
Cervical ripening balloon (CRB)
Artificial rupture of membranes with an oxytocin infusion
What is used to induce labour where intrauterine fetal death has occurred.
Oral mifepristone (anti-progesterone) plus misoprostol
What is membrane sweep
Membrane sweep involves inserting a finger into the cervix to stimulate the cervix and begin the process of labour. It can be performed in antenatal clinic, and if successful, should produce the onset of labour within 48 hours. A membrane sweep is not considered a full method of inducing labour, and is more of an assistance before full induction of labour. It is used from 40 weeks gestation to attempt to initiate labour in women over their EDD
What is Vaginal prostaglandin E2 (dinoprostone)
Vaginal prostaglandin E2 (dinoprostone) involves inserting a gel, tablet (Prostin) or pessary (Propess) into the vagina. The pessary is similar to a tampon, and slowly releases local prostaglandins over 24 hours. This stimulates the cervix and uterus to cause the onset of labour. This is usually done in the hospital setting so that the woman can be monitored before being allowed home to await the full onset of labour.
What is Cervical ripening balloon (CRB)
is a silicone balloon that is inserted into the cervix and gently inflated to dilate the cervix. This is used as an alternative where vaginal prostaglandins are not preferred, usually in women with a previous caesarean section, where vaginal prostaglandins have failed or multiparous women (para ≥ 3).
There are two means for monitoring during the induction of labour.
- Cardiotocography (CTG) to assess the fetal heart rate and uterine contractions before and during induction of labour
- Bishop score before and during induction of labour to monitor the progress
Most women will give birth within 24 hours of the start of induction of labour.
The options when there is slow or no progress are:
- Further vaginal prostaglandins
- Artificial rupture of membranes and oxytocin infusion
- Cervical ripening balloon (CRB)
- Elective caesarean section
What is Uterine Hyperstimulation
Uterine hyperstimulation is the main complication of induction of labour with vaginal prostaglandins. This is where the contraction of the uterus is prolonged and frequent, causing fetal distress and compromise.
The criteria for uterine hyperstimulation varies slightly between guidelines (always check local policies and involve experienced seniors). The two criteria often given are:
- Individual uterine contractions lasting more than 2 minutes in duration
- More than five uterine contractions every 10 minutes
Uterine hyperstimulation can lead to:
- Fetal compromise, with hypoxia and acidosis
- Emergency caesarean section
- Uterine rupture
Management of uterine hyperstimulation involves:
- Removing the vaginal prostaglandins, or stopping the oxytocin infusion
- Tocolysis with terbutaline
What is Cardiotocography (CTG)
Cardiotocography (CTG) is used to measure the fetal heart rate and the contractions of the uterus. It is also known as electronic fetal monitoring. It is a useful way of monitoring the condition of the fetus and the activity of labour.
CTG can help guide decision making and delivery. However, it should not be used in isolation for decision making, and it is essential to take into account the overall clinical picture.
Two transducers are placed on the abdomen to get the CTG readout:
- One above the fetal heart to monitor the fetal heartbeat
- One near the fundus of the uterus to monitor the uterine contractions
The transducer above the fetal heart monitors the heartbeat using _______ ________. The transducer above the fundus uses ultrasound to assess the ______ in the uterine wall, indicating _______ ______.
The transducer above the fetal heart monitors the heartbeat using Doppler ultrasound. The transducer above the fundus uses ultrasound to assess the tension in the uterine wall, indicating uterine contraction.
Indications for Continuous CTG Monitoring
The indications for continuous CTG monitoring in labour include:
- 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
There are five key features to look for on a 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
Too few contractions indicate labour is not progressing. Too many contractions can mean _____ __________ which can lead to fetal compromise. It is also important to interpret the fetal heart rate in the context of the uterine contractions.
Too few contractions indicate labour is not progressing. Too many contractions can mean uterine hyperstimulation, which can lead to fetal compromise. It is also important to interpret the fetal heart rate in the context of the uterine contractions.
_________ on CTG are generally a good sign that the fetus is healthy, particularly when occurring alongside contractions of the uterus.
Accelerations on CTG are generally a good sign that the fetus is healthy, particularly when occurring alongside contractions of the uterus.
Baseline rate and variability can be described as reassuring, non-reassuring and abnormal (adapted from NICE guidelines 2017):
Explain what each one means
Decelerations are a more concerning finding. The fetal heart rate drops in response to ______. The fetal heart rate is slowing to conserve oxygen for the vital organs. There are four types of decelerations to be aware of:
Decelerations are a more concerning finding. The fetal heart rate drops in response to hypoxia. The fetal heart rate is slowing to conserve oxygen for the vital organs. There are four types of decelerations to be aware of:
- Early decelerations
- Late decelerations
- Variable decelerations
- Prolonged decelerations
What are Early decelerations
Early decelerations are 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
What are Late decelerations
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
What are Variable decelerations
Variable decelerations are 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.
What are Prolonged decelerations
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.
It is worth remembering that the CTG is reassuring when there are
no decelerations, early decelerations or less than 90 minutes of variable decelerations with no concerning features.
What are classed as non-reassuring or abnormal decelarations depending on the features.
Regular variable decelerations and late decelerations
Prolonged decelerations are always abnormal.
Management Based on the CTG
The NICE guidelines (2017) recommend categorising the CTG based on three features of the CTG described above:
- Baseline rate
- Variability
- Decelerations
The four categories for CTG are:
- 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
The outcome of the CTG will guide management, such as:
- Escalating to a senior midwife and obstetrician
- Further assessment for possible causes, such as uterine hyperstimulation, maternal hypotension and cord prolapse
- Conservative interventions such as repositioning the mother or giving IV fluids for hypotension
- Fetal scalp stimulation (an acceleration in response to stimulation is a reassuring sign)
- Fetal scalp blood sampling to test for fetal acidosis
- Delivery of the baby (e.g. instrumental delivery or emergency caesarean section)
Fetal Bradycardia
There is a “rule of 3’s” for fetal bradycardia when they are prolonged:
- 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
What is it
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
DR C BRaVADO is a mnemonic often taught to assess the features of a CTG in a structured way. It involves assessing in order:
DR – Define Risk (define the risk based on the individual woman and pregnancy before assessing the CTG)
C – Contractions
BRa – Baseline Rate
V – Variability
A – Accelerations
D – Decelerations
O – Overall impression (given an overall impression of the CTG and clinical picture)
If you are asked to assess a CTG in your exams, use the DR C BRaVADO structure to describe each feature in turn. Give an overall impression of the CTG as being normal (all features are reassuring), suspicious, pathological, or need for urgent intervention, as described in the NICE guidelines (2017).
How is oxytocin used in labour
Oxytocin stimulates the ripening of the cervix and contractions of the uterus during labour and delivery. It also plays a role in lactation during breastfeeding.
Infusions of oxytocin are used to:
- Induce labour
- Progress labour
- Improve the frequency and strength of uterine contractions
- Prevent or treat postpartum haemorrhage
_______ is a brand name for oxytocin produced by one drug company
Syntocinon is a brand name for oxytocin produced by one drug company
Atosiban is an _______ ______ ______ that can be used as an alternative to nifedipine for tocolysis in premature labour (when nifedipine is contraindicated).
Atosiban is an oxytocin receptor antagonist that can be used as an alternative to nifedipine for tocolysis in premature labour (when nifedipine is contraindicated).
How is Ergometrine used in Labour
Ergometrine is derived from ergot plants. It stimulates smooth muscle contraction, both in the uterus and blood vessels. This makes it useful for delivery of the placenta and to reduce postpartum bleeding. It may be used during the third stage of labour (delivery of the placenta) and postpartum to prevent and treat postpartum haemorrhage. It is only used after delivery of the baby, not in the first or second stage.
Ergometrine side effects?
Due to the action on the smooth muscle in blood vessels and gastrointestinal tract, it can cause several side effects, including hypertension, diarrhoea, vomiting and angina. It needs to be avoided in eclampsia, and used only with significant caution in patients with hypertension.
___________ is a combination drug containing oxytocin (Syntocinon) and ergometrine. It can be used for prevention or treatment of postpartum haemorrhage.
Syntometrine is a combination drug containing oxytocin (Syntocinon) and ergometrine. It can be used for prevention or treatment of postpartum haemorrhage.
How is Prostaglandins used in labour
Prostaglandins act like local hormones, triggering specific effects in local tissues. Tissues throughout the entire body contain and respond to prostaglandins. They play a crucial role in menstruation and labour by stimulating contraction of the uterine muscles. They also have a role in ripening the cervix before delivery.
One key prostaglandin to be aware of is _________ which is prostaglandin E2. This is used for induction of labour, and can come in one of three forms:
One key prostaglandin to be aware of is dinoprostone, which is prostaglandin E2. This is used for induction of labour, and can come in one of three forms:
- Vaginal pessaries (Propess)
- Vaginal tablets (Prostin tablets)
- Vaginal gel (Prostin gel)
Prostaglandins act as _________ and lower blood pressure.
Prostaglandins act as vasodilators, and lower blood pressure.
NSAIDs such as ibuprofen and naproxen inhibit the action of _________
NSAIDs such as ibuprofen and naproxen inhibit the action of prostaglandins.
Can you use NSAIDs in pregnancy
SAIDs can increase blood pressure. NSAIDs are generally avoided in pregnancy, and also after delivery in women with raised blood pressure (although research has shed doubt on whether the effects on blood pressure is significant enough to justify avoiding them
NSAIDs (e.g. ibuprofen and mefenamic acid) are useful in treating dysmenorrhoea (painful periods), as they reduce the painful cramping of the uterus during menstruation.
TRUE OR FALSE
TRUE
Class of Misoprostol
How is it used in pregnancy
Misoprostol is a prostaglandin analogue, meaning it binds to prostaglandin receptors and activates them. It is used as medical management in miscarriage, to help complete the miscarriage. Misoprostol is used alongside mifepristone for abortions, and induction of labour after intrauterine fetal death.
How is mifepristone used in pregnancy
Mifepristone is an anti-progestogen medication that blocks the action of progesterone, halting the pregnancy and ripening the cervix. It enhances the effects of prostaglandins to stimulate contraction of the uterus.
Mifepristone is used alongside misoprostol for abortions, and induction of labour after intrauterine fetal death. It is not used during pregnancy with a healthy living fetus.
Class of Nifedipine
How is it used in Labour
Nifedipine is a calcium channel blocker that acts to reduce smooth muscle contraction in blood vessels and the uterus. It has two main uses in pregnancy:
- Reduce blood pressure in hypertension and pre-eclampsia
- Tocolysis in premature labour, where it suppresses uterine activity and delays the onset of labour
Class of Terbutaline
How is it used in labour
Terbutaline is a beta-2 agonist, similar to salbutamol. It stimulates beta-2 adrenergic receptors. It acts on the smooth muscle of the uterus to suppress uterine contractions. It is used for tocolysis in uterine hyperstimulation, notably when the uterine contractions become excessive during induction of labour
Class of Carboprost
How is it used in labour
Carboprost is a synthetic prostaglandin analogue, meaning it binds to prostaglandin receptors. It stimulates uterine contraction. It is given as a deep intramuscular injection in postpartum haemorrhage, where ergometrine and oxytocin have been inadequate. Notably, it needs to be avoided or used with particular caution in patients with asthma, as it can cause a potentially life-threatening exacerbation of the asthma.
Class of Tranexamic Acid#
How is it used in labour
Tranexamic acid is an antifibrinolytic medication that reduces bleeding. It binds to plasminogen and prevents it from converting to plasmin. Plasmin is an enzyme that works to dissolve the fibrin within blood clots. Fibrin is a protein that helps hold blood clots together. Therefore, by decreasing the activity of the enzyme plasmin, tranexamic acid helps prevent the breakdown of blood clots.
Tranexamic acid is used in the prevention and treatment of _________ __________
Tranexamic acid is used in the prevention and treatment of postpartum haemorrhage.
Failure to progress refers to
o when labour is not developing at a satisfactory rate. This increases the risk to the fetus and the mother. It is more likely to occur in women in labour for the first time compared with those that have previously given birth.
Progress in labour is influenced by the three P’s:
Power (uterine contractions)
Passenger (size, presentation and position of the baby)
Passage (the shape and size of the pelvis and soft tissues)
Psyche can be added as a fourth P, referring to the support and antenatal preparation for labour and delivery.
Delay in the first stage of labour is considered when there is either:
- Less than 2cm of cervical dilatation in 4 hours
- Slowing of progress in a multiparous women
Women are monitored for their progress in the first stage of labour using a ________. It is worth becoming familiar with partograms and how they are recorded.
Women are monitored for their progress in the first stage of labour using a partogram. It is worth becoming familiar with partograms and how they are recorded.
What is recorded on 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
Uterine contractions are measure in contractions per ___ _________. When the midwife says “she is contracting 2 in 10”, it means she is having 2 uterine contractions in a 10 minute period
Uterine contractions are measure in contractions per 10 minutes. When the midwife says “she is contracting 2 in 10”, it means she is having 2 uterine contractions in a 10 minute period
There are two lines on the partogram that indicate when labour may not be progressing adequately. These are labelled ___ and ______.
There are two lines on the partogram that indicate when labour may not be progressing adequately. These are labelled “alert” and “action”.
When does Second Stage of labour start
The second stage of labour lasts from 10cm dilatation of the cervix to delivery of the baby. The success of the second stage depends on “the three Ps”: power, passenger and passage. Delay in the second stage is when the active second stage (pushing) lasts over:
2 hours in a nulliparous woman
1 hour in a multiparous woman
What does power refer to
Power refers to the strength of the uterine contractions. When there are weak uterine contractions, an oxytocin infusion can be used to stimulate the uterus.
What does passenger refer to?
Passenger refers to the four descriptive qualities of the fetus:
Size - Size refers to the size of the baby. Large babies (macrosomia) will be more difficult to deliver, and there may be issues such as shoulder dystocia. The size of the head is important as this is the largest part of the fetus.
Attitude- Attitude refers to the posture of the fetus. For example, how the back is rounded and how the head and limbs are flexed.
Lie
Lie refers to the position of the fetus in relation to the mother’s body:
Longitudinal lie – the fetus is straight up and down
Transverse lie – the fetus is straight side to side
Oblique lie – the fetus is at an angle
Presentation
- Cephalic presentation – the head is first
- Shoulder presentation – the shoulder is first
- Breech presentation – the legs are first. This can be:
Complete breech – with hips and knees flexed (like doing a cannonball jump into a pool)
Frank breech – with hips flexed and knees extended, bottom first
Footling breech – with a foot hanging through the cervix
What does passage refer to
the size and shape of the passageway, mainly the pelvis.
When there are problems in the second stage of labour, interventions may be required depending on the situation. Possible interventions include:
- Changing positions
- Encouragement
- Analgesia
- Oxytocin
- Episiotomy
- Instrumental delivery
- Caesarean section
What is third stage of labour
The third stage of labour is from delivery of the baby to delivery of the placenta. Delay in the third stage is defined by the NICE guidelines (2017) as:
- More than 30 minutes with active management
- More than 60 minutes with physiological management
Active management involves intramuscular oxytocin and controlled cord traction.
Experienced midwives and obstetricians will manage failure to progress. The main options for managing failure to progress are:
Amniotomy, also known as artificial rupture of membranes (ARM) for women with intact membranes
Oxytocin infusion - first line, stimulate uterine contractions during labour
Instrumental delivery
Caesarean section
Name some Pain Relief in Labour
Simple Analgesia- paracetamol, codeine. NSAIDs avoided
Gas and Air (Entonox)- 50% nitrous oxide and 50% oxygen
Intramuscular Pethidine or Diamorphine- IM opioid. Helps with anxiety and stress.
Patient Controlled Analgesia- IV remifentanil. This involves the patient pressing a button at the start of a contraction to administer a bolus of this short-acting opiate medication.
Epidural
An epidural involves inserting a small tube (catheter) into the _______ ____ in the lower back. This is outside the ____ ______, separate from the spinal cord and CSF. Local anaesthetic medications are infused through the catheter into the epidural space, where they diffuse to the surrounding tissues and through to the spinal cord, where they have an analgesic effect. This offers good pain relief during labour. Anaesthetic options are _________ or ________usually mixed with ________.
An epidural involves inserting a small tube (catheter) into the epidural space in the lower back. This is outside the dura mater, separate from the spinal cord and CSF. Local anaesthetic medications are infused through the catheter into the epidural space, where they diffuse to the surrounding tissues and through to the spinal cord, where they have an analgesic effect. This offers good pain relief during labour. Anaesthetic options are levobupivacaine or bupivacaine, usually mixed with fentanyl.
Epidural
Adverse effects:
- Headache after insertion
- Hypotension
- Motor weakness in the legs
- Nerve damage
- Prolonged second stage
- Increased probability of instrumental delivery
What is Shoulder Dystocia
Shoulder dystocia is when the anterior shoulder of the baby becomes stuck behind the pubic symphysis of the pelvis, after the head has been delivered. This requires additional obstetric manoeuvres to enable delivery of the rest of the body. Shoulder dystocia is an obstetric emergency.
Shoulder dystocia is often caused by ________ secondary to _________ ______.
houlder dystocia is often caused by macrosomia secondary to gestational diabetes.
Presentation
Shoulder dystocia
Shoulder dystocia presents with difficulty delivering the face and head, and obstruction in delivering the shoulders after delivery of the head.
There may be failure of restitution, where the head remains face downwards (occipito-anterior) and does not turn sideways as expected after delivery of the head.
The turtle-neck sign is where the head is delivered but then retracts back into the vagina.
Management
Shoulder dystocia
Shoulder dystocia is an obstetric emergency and needs to be managed by experienced midwives and obstetricians. The first step is to get help, including anaesthetics and paediatrics. Several techniques can be used to manage the condition and deliver the baby
Episiotomy can be used to enlarge the vaginal opening and reduce the risk of perineal tears. It is not always necessary.
McRoberts manoeuvre involves hyperflexion of the mother at the hip (bringing her knees to her abdomen). This provides a posterior pelvic tilt, lifting the pubic symphysis up and out of the way.
Pressure to the anterior shoulder involves pressing on the suprapubic region of the abdomen. This puts pressure on the posterior aspect of the baby’s anterior shoulder, to encourage it down and under the pubic symphysis.
Rubins manoeuvre involves reaching into the vagina to put pressure on the posterior aspect of the baby’s anterior shoulder to help it move under the pubic symphysis.
Wood’s screw manoeuvre is performed during a Rubins manoeuvre. The other hand is used to reach in the vagina and put pressure on the anterior aspect of the posterior shoulder. The top shoulder is pushed forwards, and the bottom shoulder is pushed backwards, rotating the baby and helping delivery. If this does not work, the reverse motion can be tried, pushing the top shoulder backwards and the bottom shoulder forwards.
Zavanelli manoeuver involves pushing the baby’s head back into the vagina so that the baby can be delivered by emergency caesarean section.
Complications
The key complications of shoulder dystocia are:
- Fetal hypoxia (and subsequent cerebral palsy)
- Brachial plexus injury and Erb’s palsy
- Perineal tears
- Postpartum haemorrhage
Instrumental delivery refers to a vagina delivery assisted by either…
a ventouse suction cup or forceps
A single dose of ____ _______ is recommended after instrumental delivery to reduce the risk of maternal infection.
A single dose of co-amoxiclav is recommended after instrumental delivery to reduce the risk of maternal infection.
Indications
For instrumental delivery
The decision to perform an instrumental delivery is based on the clinical judgement of the midwife or obstetrician. Some key indications are:
- Failure to progress
- Fetal distress
- Maternal exhaustion
- Control of the head in various fetal positions
Having an instrumental delivery increases the risk to the mother of:
Postpartum haemorrhage
Episiotomy
Perineal tears
Injury to the anal sphincter
Incontinence of the bladder or bowel
Nerve injury (obturator or femoral nerve)
instrumental delivery
The key risks to remember to the baby are
Cephalohaematoma with ventouse
Facial nerve palsy with forceps
Instrumental delivery
Rarely there can be serious risks to the baby:
- Subgaleal haemorrhage (most dangerous)
- Intracranial haemorrhage
- Skull fracture
- Spinal cord injury
What is Ventouse
A ventouse is essentially a suction cup on a cord. The suction cup goes on the baby’s head, and the doctor or midwife applies careful traction to the cord to help pull the baby out of the vagina.
The main complication for the baby is cephalohaematoma. This involves a collection of blood between the skull and the periosteum.
What is Forceps Delivery
Forceps look like large metal salad tongs. They come as two pieces of curved metal that attach together, go either side of the baby’s head and grip the head in a way that allows the doctor or midwife to apply careful traction and pull the head from the vagina.
The main complication for the baby is facial nerve palsy, with facial paralysis on one side.
Forceps delivery can leave bruises on the baby’s face. Rarely the baby can develop fat necrosis, leading to hardened lumps of fat on their cheeks. Fat necrosis resolves spontaneously over time.
Rarely an instrumental delivery may result in nerve injury for the mother. This usually resolves over 6 – 8 weeks. The affected nerves may be:
Femoral nerve
Obturator nerve
The_______ nerve may be compressed against the inguinal canal during a forceps delivery. Injury to this nerve causes weakness of _____ ________, loss of the ____ reflex and numbness of the ______ _____ and _______ _____ ____
The_______ nerve may be compressed by forceps during instrumental delivery or by the fetal head during normal delivery. Injury causes weakness of ___ _________ and _______, and numbness of the _____ _____
The femoral nerve may be compressed against the inguinal canal during a forceps delivery. Injury to this nerve causes weakness of knee extension, loss of the patella reflex and numbness of the anterior thigh and medial lower leg.
The obturator nerve may be compressed by forceps during instrumental delivery or by the fetal head during normal delivery. Injury causes weakness of hip adduction and rotation, and numbness of the medial thigh.
Three other nerve injuries can occur during birth that are usually unrelated to instrumental delivery:
Lateral cutaneous nerve of the thigh
Lumbosacral plexus
Common peroneal nerve
Three other nerve injuries can occur during birth that are usually unrelated to instrumental delivery:
Lateral cutaneous nerve of the thigh
Lumbosacral plexus
Common peroneal nerve
What can these nerve injuries cause?
The lateral cutaneous nerve of the thigh runs under the inguinal ligament. Prolonged flexion at the hip while in the lithotomy position can result in injury, causing numbness of the anterolateral thigh.
The lumbosacral plexus may be compressed by the fetal head during the second stage of labour. Injury to this network of nerves nerve can cause foot drop and numbness of the anterolateral thigh, lower leg and foot.
The common peroneal nerve may be compressed on the head of the fibula whilst in the lithotomy position. Injury to this nerve causes foot drop and numbness in the lateral lower leg.
What is a Caesarean Section
A caesarean section involves a surgical operation to deliver the baby via an incision in the abdomen and uterus. It can be a planned procedure (elective caesarean) or performed where there are acute problems during the antenatal period or labour (emergency caesarean
Indications for elective caesarean include:
- Previous caesarean
- Symptomatic after a previous significant perineal tear
- Placenta praevia
- Vasa praevia
- Breech presentation
- Multiple pregnancy
- Uncontrolled HIV infection
- Cervical cancer
There are four categories of emergency caesarean section:
Category 1: There is an immediate threat to the life of the mother or baby. Decision to delivery time is 30 minutes.
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.
Category 3: Delivery is required, but mother and baby are stable.
Category 4: This is an elective caesarean, as described above.
The most commonly used skin incision is a transverse lower uterine segment incision. There are two possible incisions:
Pfannenstiel incision is a curved incision two fingers width above the pubic symphysis
Joel-cohen incision is a straight incision that is slightly higher (this is the recommended incision)
The layers of the abdomen that need to be dissected during a caesarean are
- 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
A spinal anaesthetic involves giving an injection of a local anaesthetic (such as _______) into the cerebrospinal fluid at the lower back. This blocks the nerves from the abdomen downwards.
A spinal anaesthetic involves giving an injection of a local anaesthetic (such as lidocaine) into the cerebrospinal fluid at the lower back. This blocks the nerves from the abdomen downwards.
Risks associated with having an anaesthetic:
Allergic reactions or anaphylaxis
Hypotension
Headache
Urinary retention
Nerve damage (spinal anaesthetic)
Haematoma (spinal anaesthetic)
Sore throat (general anaesthetic)
Damage to the teeth or mouth (general anaesthetic)
Measures to reduce the risks during caesarean section are:
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
Complications of c section
Generic surgical risks:
- Bleeding
- Infection
- Pain
- Venous thromboembolism
Complications in the postpartum period:
- Postpartum haemorrhage
- Wound infection
- Wound dehiscence
- Endometritis
Damage to local structures:
- Ureter
- Bladder
- Bowel
- Blood vessels
Effects on the abdominal organs:
- Ileus
- Adhesions
Hernias
- Effects on future pregnancies:
- Increased risk of repeat caesarean
- Increased risk of uterine rupture
- Increased risk of placenta praevia
- Increased risk of stillbirth
Effects on the baby:
- Risk of lacerations (about 2%)
- Increased incidence of transient tachypnoea of the newborn
is it possible to have a vaginal birth after a previous caesarean section
yes
It is possible to have a vaginal birth after a previous caesarean section, provided the cause of the caesarean is unlikely to recur. An assessment of the likelihood of success should be made in each case. Success rate of VBAC is around 75%. Uterine rupture risk in VBAC is about 0.5%.
Contraindications:
- Previous uterine rupture
- Classical caesarean scar (a vertical incision)
- Other usual contraindications to vaginal delivery (e.g. placenta praevia)
Prophylaxis for VTE in pregnancy involves:
- Early mobilisation
- Anti-embolism stockings or intermittent pneumatic compression of the legs
- Low molecular weight heparin (e.g. enoxaparin)
*
What is Uterine Rupture
Uterine rupture is a complication of labour, where 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.
Uterine rupture leads to significant ble
Uterine rupture leads to ________ ______. The baby may be released from the uterus into the peritoneal cavity. It has a high morbidity and mortality for both the baby and mother.
Uterine rupture leads to significant bleeding. The baby may be released from the uterus into the peritoneal cavity. It has a high morbidity and mortality for both the baby and mother.
The risk factors to consider are:
- Previous caesarean section- main risk factor
- Vaginal birth after caesarean (VBAC)
- Previous uterine surgery
- Increased BMI
- High parity
- Increased age
- Induction of labour
- Use of oxytocin to stimulate contractions
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
Uterine rupture is an obstetric emergency. Resuscitation and transfusion may be required. Emergency caesarean section is necessary to remove the baby, stop any bleeding and repair or remove the uterus (hysterectomy)
