OB-GYN Revision 5

Question 2

Describe what is meant by umbilical cord prolapse [1]

Answer 2

Cord prolapse is when the umbilical cord descends below the presenting part of the fetus and through the cervix into the vagina, after rupture of the fetal membranes; or can occur or occultly, where it lies alongside or just ahead of the presenting part within intact membranes.

Question 3

Explain the adverse effects of umbilical cord prolapse [2]

Answer 3

Fetal hypoxia occurs via two main mechanisms:
* Occlusion – the presenting part of the fetus presses onto the umbilical cord, occluding blood flow to the fetus.

• Arterial vasospasm – the exposure of the umbilical cord to the cold atmosphere results in umbilical arterial vasospasm, reducing blood flow to the fetus.

Question 4

What is the most significant risk factor for umbililcal cord prolapse? [1]
Name two more [2]

Answer 4

when the fetus is in an abnormal lie after 37 weeks gestation (i.e. unstable, transverse or oblique).
- provides space for the cord to prolapse below the presenting part

Breech presentation – in a footling breech, the cord can easily slip between and past the fetal feet and into the pelvis.

Polyhydramnios – excessive amniotic fluid around the fetus

Question 5

How do you manage an umbilical cord prolapse? [5]

Answer 5

1. Manually elevate the presenting part by lifting the presenting part off the cord by vaginal digital examination. Alternatively, if in the community, fill the maternal bladder with 500ml of normal saline (warmed if possible) via a urinary catheter and arrange immediate hospital transfer

2. Encourage into left lateral position with head down and pillow placed under left hip OR knee-chest position. This will relieve pressure off the cord from the presenting part. OR the patient is asked to go on ‘all fours’ until preparations for an immediate caesarian section have been carried out

3. retrofilling the bladder with 500-700ml of saline may be helpful as it gently elevates the presenting part

4. Consider tocolysis (e.g. terbutaline) – if delivery is not imminently available this will relax the uterus and stop contractions, relieving pressure off the cord.

5. Delivery is usually via emergency Caesarean section

Question 6

What is the clinical significance of a 3rd or 4th degree tear with regards to future pregnancies? [1]

Answer 6

Women that are symptomatic after third or fourth-degree tears are offered an elective caesarean section in subsequent pregnancies.

Question 7

Describe how you manage the tears [4]

Answer 7

• 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

Question 8

What are indications for an elective caesarean? [+]

Answer 8

• Previous caesarean
• Symptomatic after a previous significant perineal tear
• Placenta praevia
• Vasa praevia
• Breech presentation
• Multiple pregnancy
• Uncontrolled HIV infection
• Cervical cancer

Question 9

An elective c-section is usually performed under which type of anaesthetic [1] and at how many weeks? [1]

Answer 9

Usually these are performed after 39 weeks gestation; use spinal anaesthetic

Question 10

What is the advice about Vaginal birth after Caesarean (VBAC)? [1]

Answer 10

planned VBAC is an appropriate method of delivery for pregnant women at >= 37 weeks gestation with a single previous Caesarean delivery
- around 70-75% of women in this situation have a successful vaginal delivery

Question 11

What are contraindications to a VBAC? [2]

Answer 11

previous uterine rupture or classical caesarean scar

Question 12

The most commonly used skin incision is a transverse lower uterine segment incision. There are which two possible incisions? [2]

Answer 12

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)

Question 13

In which circumstances is a vertical incision used? [2]

Answer 13

very premature deliveries and anterior placenta praevia.

Question 14

Describe the process of a c-section

Answer 14

Initial dissection:
- Joel-cohen incision
- Pfannenstiel incision

Next a blunt dissection is used:
- involves using fingers, blunt instruments and traction to tear the tissues apart, rather than to cut them with sharp tools such as a scalpel. Go through the following layers
* 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

Question 15

What specific type of anaesthetic is used for c-sections? [1]

Answer 15

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.

General anaesthesia reserved for maternal contraindications or immediate fetal concerns.

Question 16

Describe the intraoperative [5] and postoperative [5] complications of a c-section

Answer 16

Intraoperative:
- Anaesthetic side effects - hypotension; nausea
- haemorrhage,
- uterine or uterocervical lacerations
- bladder or bowel lacerations
- ureteral injury.

Postoperative:
- Pain
- infection (endometritis, wound infection, UTIs)
* venous thromboembolism
* pulmonary atelectasis
* return to theatre
* longer hospital stay.

Question 17

Describe what the complications for future pregnancies might be like for a c-section [4]

Answer 17

Complications affecting future pregnancies may include:
* Abnormal placentation (e.g. accreta spectrum/praevia)
* Uterine rupture
* Repeat caesarean section
* higher risk of antepartum stillbirth in subsequent pregnancies and this risk increases with each successive caesarean section performed.5

Question 18

NOTE: You may hear doctors refer to Mendelson Syndrome- What is this? [1]

Answer 18

it is an eponymous name for chemical pneumonitis secondary to aspiration of stomach contents during general anaesthesia. It is more common in pregnant women.

Question 19

How can you reduce this risk of aspiration pneumonitis during c-sections? [1]

Answer 19

PPIs / H2 receptor antagonists should be offered prior to GA to reduce the risk of aspiration pneumonitis.

Question 20

What management should be given post c-section? [1]

Answer 20

Low molecular weight heparin (e.g. enoxaparin) for VTE prophylaxis

Question 21

Define what is meant by PPH [1]

Describe the two types [2]

Answer 21

Postpartum haemorrhage (PPH) is defined as blood loss of > 500 ml after a vaginal delivery or 1000ml after a caesarean section

Primary PPH:
- bleeding within 24 hours of birth

Secondary PPH:
- from 24 hours to 12 weeks after birth

Question 22

State 5 antepartum risk factors for PPH [5]

Answer 22

• Abruption
• Placenta praevia
• Multiple pregnancy
• Pre-eclampsia, gestational hypertension
• Previous PPH
• Ethnicity (i.e. Asian)
• Obesity (i.e. BMI > 30)
• Anaemia
• Uterine anomalies, fibroids

Question 23

State 5 intrapartum risk factors for PPH [5]

Answer 23

C-Section (Emergency > Elective)
Induction of Labour (IOL)
Retained placenta
Episiotomy
Instrumental
Prolonged labour
> 4kg baby
Pyrexia in labour

Question 24

What causes secondary PPH? [2]

Answer 24

Secondary PPH most commonly occurs secondary to retained products of conception and endometritis.

Question 25

Describe the management for PPH [+]

Answer 25

ABC approach:
- two peripheral cannulae, 14 gauge
- lie the women flat and communicate with her
- bloods including group and save
- commence warmed crystalloid infusion

mechanical:
* palpate the uterine fundus and rub it to stimulate contractions (‘rubbing up the fundus’)
* catheterisation to prevent bladder distension and monitor urine output

medical:
* IV oxytocin: slow IV injection followed by an IV infusion
* ergometrine slow IV or IM (unless there is a history of hypertension)
* carboprost IM (unless there is a history of asthma)
* misoprostol sublingual
* there is also interest in the role tranexamic acid may play in PPH
* oxygen regardless of sats

Surgical:
- intrauterine balloon tamponade
- 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

Question 26

TOMTIP: describe the dosing of oxytocin in PPH [1]

Answer 26

TOM TIP: The intravenous infusion of oxytocin is given as 40 units in 500 mls. You may hear midwives or obstetricians referring only to “40 units” without specifying the drug. They are referring to an oxytocin infusion for PPH.

Question 27

Which surgical management is the first line surgical managment if medical management fails in PPH? [1]

Answer 27

Intrauterine balloon tamponade

Question 28

What are the two key causes of sepsis in pregnancy? [2]

Answer 28

Chorioamnionitis
Urinary tract infections

Question 29

What is the major risk of chorioamnionitis? [1]

How do you treat? [2]

Answer 29

preterm premature rupture of membranes (however, it can still occur when the membranes are still intact) which expose the normally sterile environment of the uterus to potential pathogens

Tx:
- Prompt delivery of the foetus (via cesarean section if necessary) and administration of intravenous antibiotics

Question 30

Alongside non-specific signs of sepsis, what would indicate chorioamniotitis? [4]

How would you dx? [4

Answer 30

• Abdominal pain
• Uterine tenderness
• Vaginal discharge
• Amniotic fluid might have foul odour/appear purulent

Dx:
- WCC, ESR raised
- Lactic acid raised
- Amniotic fluid: +ve gram stain; decreased glucose; increased WCC
- Histopathological infection

Question 31

How do you manage maternal sepsis? [4]

Answer 31

Continuous maternal and fetal monitoring is required

General anaesthesia is usually required for women with sepsis, as spinal anaesthesia is avoided.

Fluids

Abx treatment:
- piperacillin and tazobactam (tazocin) & gentamicin
- amoxicillin, clindamycin and gentamicin.

Question 32

D

Describe the presentation of amniotic fluid embolisation [+]

Answer 32

It can present similarly to sepsis, pulmonary embolism or anaphylaxis:
- chills, shivering, sweating, anxiety and coughing.
- cyanosis, hypotension, bronchospasms, tachycardia. arrhythmia and myocardial infarction.

• Shortness of breath
• Hypoxia
• Hypotension
• Coagulopathy
• Haemorrhage
• Tachycardia
• Confusion
• Seizures
• Cardiac arrest

Question 33

Define what is meant by uterine rupture? [1]

What is the difference between incomplete and complete rupture? [2]

Answer 33

Uterine rupture is a complication of labour, where the muscle layer of the uterus (myometrium) ruptures

Incomplete rupture:
- the uterine serosa (perimetrium) surrounding the uterus remains intact.

Complete rupture:
- serosa ruptures along with the myometrium, and the contents of the uterus are released into the peritoneal cavity.

Question 34

What are key risk factors for uterine rupture? [5]

Answer 34

Previous caesarean section
– this is the greatest risk factor for uterine rupture.
- Classical (vertical) incisions carry the highest risk.

Previous uterine surgery
– such as myomectomy.

Induction
– (particularly with prostaglandins) or augmentation of labour.

Multiple pregnancy.

Multiparity

Question 35

Describe the presentation of uterine rupture
- pre-rupture [3]
- post rupture [4]

Describe the treatment [3]

Answer 35

Uterine rupture presents with an acutely unwell mother and abnormal CTG:
- Ceasing of uterine contractions
- Hypotension
* Tachycardia
* Collapse
* Abdominal pain
* Vaginal bleeding

Question 36

What is meant by Bandl’s ring? [1]

Answer 36

A warning sign of impending uterine rupture

Question 37

Describe what is meant by uterine invesion [1]

What is the difference between complete and incomplete uterine inversion? [2]

Answer 37

The fundus of the uterus drops down through the uterine cavity and cervix, turning the uterus inside out.

Incomplete uterine inversion (partial inversion)
- is where the fundus descends inside the uterus or vagina, but not as far as the introitus (opening of the vagina).

Complete uterine inversion
- involves the uterus descending through the vagina to the introitus.

Question 38

What is a key risk factor for uterine inversion during pregnancy? [1]

Answer 38

Uterine inversion may be there result of pulling too hard on the umbilical cord during active management of the third stage of labour.

Question 39

Describe the presentation of uterine inversion [1]

What are the managment options? [3]

Answer 39

Uterine inversion typically presents with a large postpartum haemorrhage. There may be maternal shock or collapse.

Management
* 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. It is held in place for several minutes, and medications are used to create a uterine contraction (i.e. oxytocin).
* Hydrostatic methods: This involves filling the vagina with fluid to “inflate” the uterus back to the normal position. It requires a tight seal at the entrance of the vagina, which can be challenging to achieve.
* Surgery: A laparotomy is performed (opening the abdomen) and the uterus is returned to the normal position.

Question 40

Uterine rupture:

What is the difference between scar dehiscence and rupture? [1]

Answer 40

Scar dehiscence
* Herniation of an intact amniotic membrane into an existing uterine scar

Scar rupture:
- Separation of the scar along its entire length, often with involvement of amniotic membranes