Antenatal Care: Breech Presentation, Stillbirth & Cardiac Arrest Flashcards
What does the breech presentation refer to?
Breech presentation refers to when the presenting part of the fetus (the lowest part) is the legs and bottom.
What does the cephalic presentation refer to?
Where the head is presenting first.
Frequency of breech presentation?
occurs in <5% pregnancies by 37 weeks gestation.
What are the 4 types of breech?
1) Complete
2) Incomplete
3) Extended
4) Footling
What is a complete breech?
Where the legs are fully flexed at the hips and knees
What is an incomplete breech?
With one leg flexed at the hip and extended at the knee
What is an extended breech?
Also known as frank breech.
Both legs flexed at hip and extended at knee.
What is a footling breech?
A foot is presenting through the cercix with the leg extended.
Management of babies that are breech before 36 weeks?
These often turn spontaneously - no intervention is advised.
Management options of babies that are breech at term (37 weeks)?
1) External cephalic version (ECV): can be used at term (37 weeks) to attempt to turn the fetus.
If ECV fails:
2) Choice of vaginal delivery or elective caesarian section.
Vaginal birth vs caesarian section in breech babies?
Overall, vaginal birth is safer for the mother, and caesarean section is safer for the baby.
There is about a 40% chance of requiring an emergency caesarean section when vaginal birth is attempted.
What delivery is required when the first baby in a twin pregnancy is breech?
Caesarian section is required
What is external cephalic version (ECV)?
A technique used to attempt to turn a fetus from the breech position to a cephalic position using pressure on the pregnant abdomen.
It is about 50% successful.
Success rate of ECV?
50%
When is ECV used in babies that are breech (i.e. how many weeks)?
a) for nulliparous women
b) for women that have previously given birth
a) After 36 weeks for nulliparous women
b) After 37 weeks in women that have given birth previously
What are women given prior to ECV?
Tocolysis
Purpose of tocolysis prior to ECV?
To relax the uterus before the procedure
What is tocolysis? What medication is used?
Tocolysis is with subcutaneous terbutaline.
What is terbutaline?
Beta agonist (similar to salbumatol)
mechanism of terbutaline in ECV?
Reduces the contractility of the myometrium, making it easier for the baby to turn.
What do rhesus-D negative women require before ECV?
Anti-D prophylaxis
What test is used to determine the dose of anti-D required prior to ECV in rhesus-D negative women?
A Kleihauer test
What % of babies are breech:
a) at 28 weeks
b) near term
a) 25%
b) 3%
What type of breech position is most common?
Frank breech (hips flexed and knees fully extended)
Risk factors for breech presentation?
1) uterine malformations, fibroids
2) placenta praevia
3) polyhydramnios or oligohydramnios
4) fetal abnormality (e.g. CNS malformation, chromosomal disorders)
5) prematurity (due to increased incidence earlier in gestation
What is cord prolapse?
An umbilical cord prolapse happens when the umbilical cord slips down in front of the baby after the waters have broken.
What complication is more common in breech presentation?
Cord prolapse
What are some absolute contraindications to ECV?
1) where caesarean delivery is required
2) antepartum haemorrhage within the last 7 days
3) abnormal cardiotocography
4) major uterine anomaly
5) ruptured membranes
6) multiple pregnancy
What is umbilical cord prolapse?
Umbilical cord prolapse involves the umbilical cord descending ahead of the presenting part of the fetus.
This occurs in 1/500 deliveries.
Risk of untreated cord prolapse?
Can lead to compression of the cord or cord spasm –> can cause fetal hypoxia –> eventually irreversible damage or death.
Risk factors for cord prolapse?
- prematurity
- multiparity
- polyhydramnios
- twin pregnancy
- cephalopelvic disproportion
- abnormal presentations e.g. Breech, transverse lie
When do 50% of cord prolapses occur?
at artificial rupture of the membranes.
How is diagnosis of cord prolapse made?
Usually made when:
a) the fetal heart rate becomes abnormal
b) the cord is palpable vaginally, or if the cord is visible beyond the level of the introitus.
Management of cord prolapse?
Obstetric emergency.
1) the presenting part of the fetus may be pushed back into the uterus to avoid compression
2) if the cord is past the level of the introitus, there should be minimal handling and it should be kept warm and moist to avoid vasospasm
3) the patient is asked to go on ‘all fours’ until preparations for an immediate caesarian section have been carried out
4) tocolytics may be used to reduce uterine contractions
5) retrofilling the bladder with 500-700ml of saline may be helpful as it gently elevates the presenting part
1st line method of delivery in cord prolapse?
Caesarian section
What class of drug reduces uterine contractions?
tocolytis
Define stillbirth
The birth of a dead fetus after 24 weeks gestation.
Stillbirth is the result of intrauterine fetal death (IUFD).
Stillbirth vs miscarriage?
Miscarriage - before 24 weeks
Stillbirth - after 24 weeks
Causes of stillbirth?
- Unexplained (around 50%)
- Pre-eclampsia
- Placental abruption
- Vasa praevi
- Cord prolapse or wrapped around fetal neck
- Obstetric cholestasis
- Diabetes
- Thyroid disease
- Infections e.g. rubella, parvovirus, listeria
- Genetic abnormalities or congenital malformations
What are some factors that increase the risk of stillbirth?
1) Foetal growth restriction
2) Smoking
3) Alcohol
4) Increased maternal age
5) Maternal obesity
6) Twins
7) Sleeping on the back (as opposed to either side)
How can risk of stillbirth be assessed & mitigated?
1) A risk assessment for having a baby that is small for gestational age (SGA) or with fetal growth restriction (FGR) is performed on all pregnant women.
Having risk factors for SGA increases the risk of stillbirth.
Those at risk have the fetal growth closely monitored with serial growth scans.
2) Risk of pre-eclampsia - aspirin
3) Treat modifiable risks e.g. stop smoking, effective control of diabetes, avoid alcohol, advise sleeping on side (not back)
What are the 3 key symptoms to always ask about during pregnancy?
1) Reduced fetal movements
2) Abdominal pain
3) Vaginal bleeding
What is the investigation of choice for diagnosing intrauterine fetal death (IUFD)?
US scan: to visualise fetal heartbeat to confirm the fetus is still alive.
Why is a repeat US scan offered in intrauterine foetal death?
Passive fetal movements are possible after IUFD, and a repeat scan is offered to confirm the situation.
What must rhesus-D negative women be offered when intrauterine fetal death (IUFD) iis diagnosed?
anti-D prophylaxis
1st line delivery for most women after IUFD?
Vaginal birth.
Women given choice of:
1) induction of labour
2) expectant management (provided immediate delivery is not required e.g. sepsis, pre-eclampsia, haemorrhage)
What is expectant management of stillbirth?
awaiting natural labour and delivery: need close monitoring as the condition of the fetus will deteriorate with time.
What is used in the induction of labour in stillbirth?
Combination of:
1) oral mifepristone (anti-progesterone)
2) vaginal or oral misoprostol (prostaglandin analogue)
What can be used to suppress lactation after stillbirth?
Dopamine agonists (e.g. cabergoline)
What class of drug is mifepristone?
anti-progesterone
What class of drug is misoprostol?
Prostaglandin analogue
What class of drug is cabergoline?
Dopamine agonists
What testing can be carried out after stillbirth (with parental consent)?
To determine the cause:
1) Genetic testing of the fetus and placenta
2) Postmortem examination of the fetus (including xrays)
3) Testing for maternal and fetal infection
4) Testing the mother for conditions associated with stillbirth, such as diabetes, thyroid disease and thrombophilia
Purpose of testing post-stillbirth?
Identifying the cause can help reduce the risk in future pregnancies.
Support after stillbirth?
Counselling is offered to women, partners and family members.
They are supported with their individual wishes, such as seeing the baby, naming the baby and keeping photographs (although not persuaded either way with what to do).
They are also supported with wishes for funeral arrangements and services.
What are the reversible causes of adult cardiac arrest (4 Ts and 4 Hs)?
4 Ts:
1) Thrombosis (PE or MI)
2) Tension pneumothorax
3) Toxins
4) Tamponade (cardiac)
4 Hs:
1) Hypoxia
2) Hypovolaemia
3) Hypothermia
4) Hyperkalaemia, hypoglycaemia, and other metabolic abnormalities
Others:
- Eclampsia
- Intracranial haemorrhage
What are the 3 major causes of cardiac arrest in pregnancy?
1) Obstetric haemorrhage: major cause of severe hypovolaemia and cardiac arrest.
2) PE
3) Sepsis leading to metabolic acidosis and septic shock
What are 5 major causes of massive obstetric haemorrhage?
1) Ectopic pregnancy (earlier pregnancy)
2) Placental abruption (including concealed haemorrhage)
3) Placenta praevia
4) Placenta accreta
5) Uterine rupture
How can a pregnant woman lying on her back lead to hypotension (sometimes enough to lead to the loss of cardiac output and cardiac arrest)?
Aortocaval compression:
1) When a pregnant woman lies on her back (supine), the mass of the uterus can compress the inferior vena cava and aorta.
2) The compression on the vena cava is most significant, as it reduces the blood returning to the heart (venous return)
3) This reduces the cardiac output, leading to hypotension.
4) In some instances, this can be enough to lead to the loss of cardiac output and cardiac arrest.
Solution to aortocaval compression?
The vena cava is slightly to the right side of the body –> place the woman in the left lateral position, lying on her left side, with the pregnant uterus positioned away from the inferior vena cava.
This should relieve the compression on the inferior vena cava and improve venous return and cardiac output.
What factors make resuscitation more complicated in pregnancy?
1) Aortocaval compression
2) Increased oxygen requirements
3) Splinting of the diaphragm by the pregnant abdomen
4) Difficulty with intubation
5) Increased risk of aspiration
6) Ongoing obstetric haemorrhage
Principles in pregnancy for resuscitation?
1) A 15 degree tilt to the left side for CPR, to relieve compression of the inferior vena cava and aorta
2) Early intubation to protect the airway
3) Early supplementary oxygen
4) Aggressive fluid resuscitation (caution in pre-eclampsia)
5) Delivery of the baby after 4 minutes, and within 5 minutes of starting CPR
When is immediate caesarian section performed in pregnant women needing resuscitation?
1) There is no response after 4 minutes to CPR performed correctly
2) CPR continues for more than 4 minutes in a woman more than 20 weeks gestation
In cardiac arrest in pregnancy, how soon after starting CPR should baby and placenta be delivered?
The aim is to deliver the baby and placenta within 5 minutes of CPR commencing.
CPR should be continued for more than 4 minutes.
The operation is performed at the site of the arrest, for example, in A&E resus or on the ward.
What is the primary reason for immediate delivery in cardiac arrest in pregnancy?
Improve the survival of the mother
Where is delivery performed in cardiac arrest in pregnancy?
at the site of the arrest, for example, in A&E resus or on the ward.
How can delivery improve maternal outcomes in cardiac arrest in preganancy?
Delivery improves the venous return to the heart, improves cardiac output and reduces oxygen consumption.
It also helps with ventilation and chest compressions.
Delivery increases the chances of the baby surviving, although this is secondary to the survival of the mother.
