450 SBAs in Clinical Specialties - Management of Labour and Delivery Flashcards
- Analgesia in labour
A 24-year-old woman is in her first pregnancy. She has no significant medical history. She is 40 weeks and 2 days pregnant and has been contracting for 4 days. She is not coping with the pain. She has been given intramuscular pethidine. On examination she is found to be 4 cm dilated (fetus in the occipito-posterior position) having been the same 4 hours previously. What analgesia would you recommend?
A. Remifentanil
B. Pethidine
C. Diamorphine
D. Epidural injection
E. Entonox
D. Epidural injection
1 DThis woman has had a very long latent phase of labour (the latent phase
usually being no longer than 24 hours). Her cervix is now 4 cm and she is in the active phase of labour. Unfortunately, the fetal position of occipito-posterior is associated with slower labours. She has not made progress over a 4-hour period so an assessment into whether there is a problem with the powers (contractions), passage (shape of pelvis) and passenger (size and position) needs to be undertaken. There is likely to be a significant amount of time left before baby is born. All question choices are analgesia options in labour. Remifentanil (A) is given through an infusion pump and tends to be used where there is a contraindication to having an epidural or a spinal. Pethidine (B) has been given before but had little effect so she is unlikely to want this again. Some hospitals use diamorphine (C) instead of pethidine. There is little difference between the two with some units preferring one or the other. All opiates primarily have a sedative effect rather than an analgesic effect in labour. Entonox (E) can be a helpful adjunct to pain relief but it is unlikely that this will be enough to ease her through the remainder of the labour. An epidural (D) would be the most appropriate analgesia to offer this woman. This is based on the expected length of labour ahead and also the likelihood of augmentation with syntocinon as she has made little progress in the active stage of labour.
- Intrapartum care (1)
A 36-year-old woman is 41 weeks pregnant and is established in spontaneous labour. She is contracting three times every 10 minutes and has ruptured her membranes. She is draining significant meconium stained liquor. Her cervix is 7 cm dilated. Her midwife has started continuous electronic fetal monitoring using a cardiotocograph (CTG). The baseline rate has been 155, with variability of 2 beats per minute, for the past 60 minutes. There are no accelerations and no decelerations. What is the most appropriate management?
A. Pathological CTG – needs delivery
B. Suspicious CTG – needs delivery after fetal blood sampling (FBS)
C. Suspicious CTG – change maternal position, intravenous fluids and reassess in 20 minutes
D. Suspicious CTG – perform fetal blood sampling and deliver if abnormal
E. Normal CTG – do nothing
D. Suspicious CTG – perform fetal blood sampling and deliver if abnormal
2 D Classification of CTGs is an important part of intrapartum care and it is imperative that interpretation is uniform. There are four features to a CTG: baseline rate, variability, accelerations and decelerations.
- Intrapartum care (2)
A 19-year-old woman is giving birth to her first baby. She has been pushing for an hour and the fetal head has been on the perineum for 6 minutes. There seems to be a restriction due to resistance of her tissues. Her midwife carries out a right mediolateral episiotomy. Which of the following structures should not be cut with the episiotomy?
A. Bulbospongiosus
B. Superficial transverse perineii (STP)
C. Vaginal mucosa
D. Perineal membrane
E. Ischiocavernosus
E. Ischiocavernosus
3 E If the episiotomy is performed correctly it should avoid the ischiocavernosus (E). This muscle goes from the crus of the clitoris to the ischial tuberosity. The episiotomy should be at least 45° from the midline. The episiotomy creates extra space for delivery of the fetal head. Bulbospongiosus (A) inserts into the fascia of the corpus cavernosa and originates from the perineal body. STP (B) goes from the ischial ramus and tuberosity to the perineal body. The vaginal mucosa (C) will be involved as the inside blade of the scissors will be in the vagina. The perineal membrane (D) has two parts, the dorsal and ventral. The ventral part consists of the urethra and surrounding structures. The dorsal part consists of the attachment of the lateral wall of the vaginal and perineal body to the ischiopubic rami. The episiotomy will disrupt this.
- Intrapartum care (3)
A 25-year-old woman in her first pregnancy has a pathological CTG. Her cervix is 5 cm dilatated. Which of the following will not increase the risk to the fetus if the doctor performed a fetal blood sample?
A. Human immunodeficiency virus (HIV)
B. Human papilloma virus (HPV)
C. Maternal immune thrombocytopenia
D. Factor IX deficiency
E. Hepatitis C
B. Human papilloma virus (HPV)
4 B CTGs are a sensitive screening tool but have a high false-positive rate. For this reason whenever you are faced with a pathological CTG a fetal blood sample can help to reassure you that the fetus is coping with labour. HIV (A), and hepatitis C (E) are blood-borne viruses and invasive tests (such as FBS) increase the risk of vertical transmission. FBS should be avoided in women with factor IX deficiency (D) (haemophilia B) as there is a risk that the fetus may also be affected. In maternal immune thrombocytopenia (C) there is a risk that the fetus may also have a low platelet count. HPV (B) is the correct answer as FBS does not increase the risk to the fetus. HPV is associated with cervical cancer, especially HPV types 16, 18, 31 and 33.
- Cord prolapse
A multiparous woman is admitted to the labour ward with regular painful contractions. On examination she is 9 cm dilated with intact membranes and is coping well with labour pains. Forty minutes later her membranes rupture while she is being examined and you see the umbilical cord hanging from her vagina. You inform the woman what has happened. She is now fully dilated, the fetal position is Direct occipitoanterior, and the presenting part is below the ischial spines. What do you do next?
A. Gain intravenous access, call for help and stop the woman pushing
B. Perform a grade 1 emergency caesarean section
C. Call for help, perform an episiotomy and commence pushing
D. Call for help and prepare for an instrumental delivery
E. Elevate the presenting part by inserting a vaginal pack
D. Call for help and prepare for an instrumental delivery
5 DIf the cord is felt below the presenting part with ruptured membranes, there is a cord prolapse. This is an obstetric emergency since the cord can either become obstructed or go into spasm and starve the fetus of oxygen. Delivery needs to be expedited. Answer (A) is partially correct as you will need help and probably need IV access. Help is very important here. You will need trained obstetric, anaesthetic and midwifery staff. Generally, women with cord prolapse should be delivered immediately, in theatre. If the cervix is not fully dilated, they should be delivered by grade 1 caesarean section (B). In this case however, a vaginal delivery is the quickest option. She is a multiparous woman with a favourable fetal head position which is low in the pelvis. Answer (C) is inappropriate as delivery needs to be as quick as possible and an episiotomy alone will not guarantee delivery of the fetus. Elevating the presenting part is very important as this will relieve pressure on the cord, but not with a pack (E). In the community the midwife should either use their hand to move the fetal head from the cord, or a catheter can be inserted into the bladder and filled with 500 mL normal saline to elevate the presenting part. Answer (D) would be the best option in this case as it is most likely to effect the quickest delivery.
- Active management of labour
A 34-year-old para 0 has been admitted for a post-dates induction of labour at 42 weeks. She has received 4 mg PGE2 (prostaglandin) vaginally. After 72 hours her cervix is 5 cm dilated. Four hours later she is still 5 cm dilated. On abdominal examination the fetus appears to be a normal size. The fetal head position is left occipito-transverse, and the station is −1. There is no moulding but a mild caput. She is contracting two times in every 10 minutes and has an epidural in situ. You are asked to review and make a management plan. What would be the most appropriate plan?
A. Re-examine in 4 hours provided the baby is not distressed
B. Discuss the situation with the patient and offer her a caesarean section
C. Start an oxytocin infusion and intermittent monitoring and reassess in 4 hours
D. Insert another 1 mg PGE2 as she is not contracting and reassess in 2 hours
E. Start an oxytocin infusion, commence continuous monitoring and reassess within an appropriate time span
E. Start an oxytocin infusion, commence continuous monitoring and reassess within an appropriate time span.
6 E This question focuses on delay in the first stage of labour. We know that she is in active labour as her cervix is 5 cm dilated (active labour is usually believed to have commenced once the cervix is more than 3 cm dilated). When considering labour we must think about the ‘passage, passenger and powers’. This woman’s labour has arrested, and she is only contracting twice every 10 minutes. It is technically difficult to assess the ‘passage’ but one can gauge obstruction when performing a vaginal examination by assessing the degree of caput or moulding of the head. The ‘passenger’ can be similarly difficult to assess but abdominal examination is mandatory to assess the size of the baby and gauge how much fetal head remains in the abdomen. Putting this together it would appear that the reason for the arrest of labour is a suboptimal contraction pattern. Option (A) is not appropriate as this woman’s labour has not progressed in the last 4 hours. This woman may end up requiring caesarean delivery (B) but at this point it is more appropriate to offer augmentation. It is not appropriate to intermittently monitor a labour augmented by oxytocin so (C) is also incorrect: augmentation of labour carries a risk of hyperstimulation and thus requires continuous fetal monitoring. This woman is now in labour so there is no place for further PGE2 (D) to dilate the cervix. Option (E) is the best answer. There may be debate about the timing of the subsequent examination but the aim is to achieve a vaginal delivery.
- Intrapartum care (4)
A mother comes to labour ward who is low risk, in labour at term. The unit is short staffed and there are not enough midwives to provide intermittent auscultation of the fetal heart. You decide to start continuous electronic monitoring (CTG). She is an epidemiologist and asks you about the CTG and how it will help her labour and prevent her baby suffering harm. Which of the following would you tell her? Continuous monitoring has a:
A. High sensitivity and low specificity
B. High sensitivity and high specificity
C. Low sensitivity and low specificity
D. Low sensitivity and high specificity
E. High sensitivity and high positive predictive value
A. High sensitivity and low specificity
7 A The CTG was introduced as a way to reduce the number of babies born with fetal acidosis, and poor Apgar scores. In reality, the only proven benefit is a reduction in neonatal seizures. Currently, there is no clear evidence of a reduction in perinatal mortality or hypoxic brain injuries. However, the CTG is very sensitive so if the fetus becomes acidotic then it will pick this up as change becoming suspicious/pathological. However, it is not very specific, with a high false-positive rate. Nearly 50 per cent of babies delivered because of a pathological CTG will have normal blood gases. A monitoring tool which had low sensitivity and low specificity (C) would be of no use. A monitoring tool with low sensitivity and high specificity (D) would seldom have a false-positive result; however, it would miss patients with the condition you were looking for. A tool that was highly sensitive and specific monitoring or one with high positive predictive values (B, E), but these are unfortunately at present unavailable in relation to fetal monitoring.
- fetal loss
A 29-year-old woman comes to the labour ward complaining that her baby has not been moving for 72 hours. She is 36 weeks pregnant. Otherwise her pregnancy has been complicated with gestational diabetes for which she is taking insulin. On examination you fail to pick up the fetal heart. You confirm the diagnosis of an intrauterine death. The scan shows no liquor and the baby is transverse. After a long discussion you explain that she unfortunately needs to deliver her baby. What is the best way for her to deliver her baby?
A. Induction with oral mifepristone and oral misoprostol
B. Induction with oral mifepristone and vaginal misoprostol
C. Induction with oral misoprostol
D. Induction with vaginal dinoprostone
E. Caesarean section
E. Caesarean section
8 E Stillbirth is a tragic and often unpredictable event. There is an increase in stillbirths with diabetes. In this case, stillbirth may have been avoidable if the woman had attended hospital sooner than 72 hours after noticing a loss of fetal movements. Induction of labour for an intrauterine death normally involves using mifepristone for cervical ripening and misoprostol (A, B) to bring about the onset of contractions. Dinoprostone (D) is also used routinely in many institutions for induction of labour. Induction with misoprostol alone (C) in a woman with an unripe cervix is unlikely to be successful. In this scenario, however, the complicating factor is that there is no liquor and this baby is transverse at term. This baby will not deliver vaginally and the only option available therefore is caesarean delivery. Moreover, inducing a labour for transverse lie increases the risk of uterine rupture.
- Complications of delivery
A 24-year-old woman with gestational diabetes has been progressing normally through an uncomplicated labour. The midwife delivers the head but it retracts and does not descend any further. What should the midwife do next?
A. Pull the emergency bell and place the woman in McRobert’s position
B. Place the woman on all fours and instruct her not to push
C. Pull the emergency bell and commence rotational manoeuvres for shoulder dystocia
D. Pull the emergency cord and ask your helper to apply fundal pressure
E. Pull the emergency bell and prepare for emergency caesarean delivery
A. Pull the emergency bell and place the woman in McRobert’s position
9 A This woman’s delivery is complicated by shoulder dystocia, a risk factor for which is gestational diabetes. It is often heralded by the ‘turtleneck’ sign, where the head delivers but then appears to retract. It is an obstetric emergency. A series of manoeuvres are performed in a set order, the most important of which is placing the woman into McRobert’s position (A) (knees and legs maximally flexed) to give the pelvic outlet its maximum possible diameter. In the majority of cases, the baby will deliver spontaneously with this manoeuvre. Placing the woman on all fours (B) and internal rotational manoeuvres (C) may all be attempted, and suprapubic pressure if McRobert’s position have failed to disimpact the shoulder, but they are not the first step. Caesarean delivery is a last-ditch attempt to deliver the baby if all other methods have failed (E); in addition it requires Zavanelli’s manoeuvre, where the baby is manually replaced into the uterine cavity. Fundal pressure increases the risk of brachial plexus injuries, causing Erb’s or Klumpke’s palsies.
- Complications of labour
A 29-year-old multiparous woman is in established labour contracting strongly. She is 4 cm dilated and had been having regular painful contractions for 6 hours before they stopped abruptly, heralded by a sudden onset of severe, continuous lower abdominal pain. The fetal heart trace is difficult to identify, and the tocometer does not register a signal. What is the most appropriate management?
A. Fetal assessment with formal ultrasound scan
B. FBS
C. Immediate trial of delivery in theatre, with resuscitation facilities on standby
D. Immediate caesarean delivery
E. Expedite delivery with synthetic oxytocin infusion
D. Immediate caesarean delivery
10 D This woman is likely to have suffered a uterine rupture, a potentially catastrophic event for both her and her baby. Although signs and symptoms are often subtle, the presentation here would strongly suggest rupture. Often there is significant fetal heart rate abnormality following rupture, and the tocometer will not register any contractions. Immediate surgical intervention (D) is necessary to save the life of the baby and mother, who is at risk of haemorrhagic shock. A ‘crash’ caesarean delivery is normally performed with subsequent repair, if possible, of the uterus, although a caesarean hysterectomy is sometimes necessary. In this case formal ultrasound offers little more useful information than can be garnered from the CTG (other than clarification of the presence of a fetal heart rate) (A). This should never replace emergency delivery if rupture is clearly present. FBS (B) is useful in labour when a CTG trace has become suspicious but in this case it has no place. Using an oxytocin infusion (E) would be contraindicated in the presence of suspected uterine rupture as it increases the strength and frequency of contractions and could exacerbate the rupture. Trial of vaginal delivery in theatre (C) is not appropriate as the cervix is only 4 cm dilated.
- Obstetric anaesthesia
A 23-year-old woman is in her first labour. Her cervix is 6 cm dilated and she is in distress. She is asking for an epidural. Before you call the anaesthetist you check her history. Which of the following would be an absolute contraindication to an epidural?
A. Previous spinal surgery
B. Hypotension
C. Mitral stenosis
D. Multiple sclerosis
E. Aortic stenosis
B. Hypotension
11 B Epidural anaesthesia is commonplace on a labour ward. Care must be taken when offering patients epidurals to consider conditions that might make the procedure more difficult. Absolute contraindications include patient refusal, allergies to anaesthetic agents, systemic infection, skin infection over the intended epidural site, bleeding disorders, platelet count less than 80 000 / mL and uncontrolled hypotension. Hypotension (B) is of vital importance: the epidural will cause a peripheral vasodilation and worsen any pre-existing hypotension. This peripheral vasodilation is the reason why most obstetric anaesthetists preload the patient with 1 L of intravenous fluid before giving the epidural agent. Relative contraindications include conditions where the heart cannot adapt easily to circulatory changes such as hypertrophic obstructive cardiomyopathy, aortic stenosis or mitral stenosis (C). Anatomical abnormalities like spina bifida or previous spinal surgery (A) may make an epidural technically difficult but are not contraindications. Neurological conditions such as multiple sclerosis may be exacerbated by an epidural but again this is not a contraindication. Most hospitals now run anaesthetic clinics prior to labour, which is the optimum time for an assessment to be made about the woman’s suitability for regional anaesthesia.
- Management of the second stage
A 38-year-old nulliparous woman has had an uncomplicated pregnancy. She has laboured very quickly and is 10 cm dilated. The fetal heart falls to 60 for 4 minutes. She is pushing effectively and the head is 1 cm below the ischial spines. You prepare for forceps delivery in the room. She has had no analgesia so you quickly insert a pudendal nerve block and deliver the baby 4 minutes later in good condition. Which of the following is not a branch of the pudendal nerve?
A. Inferior anal nerve
B. Perineal nerve
C. Dorsal nerve of the clitoris
D. Posterior labial nerve
E. Genital branch of the genitofemoral nerve
E. Genital branch of the genitofemoral nerve
12 E The pudendal nerve arises from the ventral rami of the 2nd, 3rd and 4th nerves of the sacrum. It then passes between piriformis and coccygeus leaving the pelvis through the greater sciatic foramen. It then crosses the ischium and re-enters via the lesser sciatic foramen. It runs forward in the pudendal canal with the pudendal vessels. The inferior anal (A) and inferior haemorrhoidal nerves are the first to leave the pudendal nerve. The main benefit of the pudendal block for operative obstetrics is the effect it has on the perineal nerve (B). The dorsal nerve of the clitoris (C) is a terminal branch of the pudendal nerve that should not be involved in your delivery if you have to perform an episiotomy. Option (D) is another branch of the pudendal nerve. The block will help analgesia if there is any trauma to the labia. The genital branch of the genitofemoral nerve (E) does not innervate the perineum; instead it arises from L1 and L2 and descends over psoas major before entering the deep inguinal ring. It terminates with the round ligament in the female.
- Obstetric emergencies
The obstetric team is alerted to a blue-light trauma call expected in accident and emergency. A 28-year-old woman who is 37 weeks pregnant has been involved in a high-speed road traffic collision. On arrival, where the obstetric team is on standby, her Glasgow Coma Scale score is 5 and she has a tachycardic hypotension. What is the most appropriate management sequence?
A. Resuscitation according to Advanced Trauma Life Support (ATLS) guidelines and transfer to the labour ward
B. Transfer to the CT scanner in preparation for immediate trauma laparotomy
C. Resuscitation according to ATLS guidelines and fetal assessment with the patient in left lateral tilt
D. Resuscitation according to ATLS guidelines with immediate caesarean delivery
E. Resuscitation according to ATLS guidelines and corticosteroids for fetal lung maturation
C. Resuscitation according to ATLS guidelines and fetal assessment with the patient in left lateral tilt
13 C Although obstetric major trauma is uncommon, this question tests the candidate’s ability to apply basic obstetric and emergency medicine knowledge to unusual circumstances. By the process of elimination, only one answer is appropriate. The transfer of an unstable polytrauma patient is dangerous, particularly if as in this case there is evidence of haemorrhagic shock, so options (A) and (B) are incorrect. Steroids (E) for lung maturation are not required at this gestation. Corticosteroids promote fetal lung maturity and are used, if time permits, if a woman presents in early preterm labour before 34 weeks gestation. Although perimortem caesarean section may be performed in accident and emergency, this woman, although unwell, has a cardiac output which may respond to resuscitative measures, so immediate caesarean delivery (D) is unwarranted and may put her at further risk. Placing the woman in a left lateral tilt (C) is important to permit increased venous return, while fetal assessment will determine the fetal state following the accident and may contribute to the management plan.
- Third degree tears
A 24-year-old woman is seen after her normal vaginal birth. The midwife who delivered the baby is concerned that there is a third degree tear. Having examined the woman the obstetrician confirms a third degree tear. The woman is taken to theatre to repair the external anal sphincter. Which of the following is not a risk factor for third degree tear?
A. Forceps delivery
B. Second stage of labour lasting over an hour
C. Shoulder dystocia
D. Ventouse delivery
E. Maternal age
D. Ventouse delivery
14 D One per cent of all vaginal births result in a third degree tear. It is imperative that the tear is identified at the time of delivery so that it can be repaired appropriately. A 3a tear involves less than 50 per cent of the external anal sphincter (EAS), while a 3b tear involves more than 50 per cent of the EAS. A 3c tear involves both EAS and the internal anal sphincter. All of the options are risk factors except maternal age. Others include being primiparous, induction of labour, a large (greater than 4 kg) baby, occipitoposterior position and midline episiotomy. Once repaired the patient needs to be debriefed, be prescribed antibiotics and stool softeners and be offered a 6-week review.
