Intrapartum Care II

Question 1

There are two main instruments used in operative deliveries – the ventouse and the forceps.

In general, the first instrument used is the most likely to succeed. The choice is operator dependent, but forceps tend to have a lower risk of fetal complications, and a higher risk of maternal complications. The general rule is, if after three contractions and pulls with any instrument there is no reasonable progress, the attempt should be abandoned.

What is the ventouse and how is it used?

Answer 1

• instrument that attaches a cup to foetal head via a vacuum
• A) an electrical pump attached to a siliastic cup - only suitable if foetus in an occipital-anterior position
• B) a hand-held, disposable device AKA “Kiwi” - an omni-cup, can be used for all foetal positions and rotational deliveries
• to use ventouse, cup is applied with its centre over the flexion point on foetal skull (in midline, 3cm anterior to posterior fontanelle)
• during uterine contractions, traction is applied perpendicular to cup

Ventouse deliveries are associated with: lower success rate, less maternal perineal injuries, less pain, more cephalhaematoma, more subgaleal haematoma + more foetal retinal haemorrhage

Question 2

The decision to perform an operative vaginal delivery should be based on the entire clinical scenario in the 2^nd stage of labour - is there a valid clinical indication to intervene? Is the patient a suitable case for an instrumental delivery?

What are the common indications of operative/assisted vaginal delivery?

Answer 2

Question 3

What are forceps, how are they used and what are they associated with?

Answer 3

• double-bladed instruments
• Rhodes, Neville-Barnes or Simpsons → used for OA positions
• Wrigley’s → used at caesarian section
• Kielland’s → for rotational deliveries
• blades are introduced into pelvis, taking care not to cause trauma to maternal tissue + applied around sides of foetal head w/ blades then locked together
• gentle traction applied during uterine contractions, following J shape of the maternal pelvis

Use of forceps associated with: higher rate of 3^rd/4^th degree tears, less often used to rotate + doesn’t require maternal effort.

Question 4

In general, what are the pre-requisites for instrumental delivery?

Answer 4

• fully dilated
• ruptured membranes
• cephalic presentation
• defined foetal position
• foetal head at least level of ischial spines, and no more than 1/5 palpable per abdomen
• empty bladder
• adequate pain relief
• adequate maternal pelvis

Question 5

What are contraindications for instrumental delivery?

Answer 5

• ABSOLUTE:
  
  • unengaged foetal head in singleton pregnancies
  • incompletely dilated cervix in singleton pregnancies
  • true cephalo-pelvic disproportion (where foetal head is too large to pass through maternal pelvis)
  • breech + face presentations, and most brow presentations
  • preterm gestation (<34wks) for ventouse
  • high likelihood of any foetal coagulation disorder for ventouse
• RELATIVE:
  
  • severe non-reassuring foetal status w/ station of head above level of pelvic floor - ie. foetal scalp not visible
  • delivery of second twin when head has not quite engaged or the cervix has reformed
  • prolapse of umbilical cord w/ foetal compromise when cervix is completely dilated and station is mid-cavity

Question 6

What are the foetal and maternal complications of operative vaginal delivery?

Answer 6

• FOETAL:
  
  • neonatal jaundice
  • scalp lacerations
  • cephalhaematoma
  • subgaleal haematoma
  • facial bruising
  • facial nerve damage
  • skull fractures
  • retinal haemorrhage
• MATERNAL:
  
  • vaginal tears
  • 3rd/4th degree tears (1:100 normal delivery, 4:100 ventouse, 10:100 forceps)
  • VTE
  • incontinence
  • PPH
  • shoulder dystocia
  • infection

Question 7

The rate of caesarean section has increased significantly in recent years, largely secondary to an increased fear of litigation.

What are the two main types of C-section?

Answer 7

• lower segment caesarean section → now comprises 99% of cases
• classic caesarean section → longitudinal incision in upper segment of uterus

Question 8

How are C-sections classified?

Answer 8

Emergency Caesarean sections are most commonly for failure to progress in labour or suspected/confirmed fetal compromise

Question 9

What are the indications for caesarean section?

Answer 9

• absolute cephalopelvic disproportion
• placenta praevia grades 3/4
• pre-eclampsia
• post-maturity
• IUGR
• foetal distress in labour/prolapsed cord
• failure of labour to progress
• malpresentations: brow
• placental abruption: only if foetal distress; if dead deliver vaignally
• vaginal infection eg. active herpes
• cervical cancer

Question 10

What are the immediate complications of C-Section?

Answer 10

• postpartum haemorrhage (>1000ml)
• wound haematoma (inc inpt w/ large BMI/diabetes/immunocompromised)
• intra-abdominal haemorrhage
• bladder/bowel trauma (more common in pts who have had prev abdo surgery)
• neonatal:
  
  • transient tachypnoea of newborn
  • foetal lacerations (1-2% risk, higher w/ prev membrane rupture)

Question 11

What are the intermediate and late complications of C-section?

Answer 11

• infection → UTI, endometritis, respiratory
• venous thromboembolism
• urintary tract trauma (fistula)
• subfertility
• regret + other negative psychological sequelae
• rupture/dehiscence of scar at next labour VBAC
• placenta praevia/accreta
• caesarean scar ectopic pregnancy

Question 12

What is the issue with vaginal birth after caesarean section (VBAC)?

Answer 12

• planned VBAC associated w/ 1/200 risk of uterine scar rupture
• there is small inc risk of placenta praevia +/- accreta in future pregnancies and of pelvic adhesions
• success rate of planned VBAC is 72-75%, however this is as high as 85-90% in women who have had a previous vaginal delivery
• all women undergoing VBAC should have continuous foetal monitoring in labour as change in foetal heart rate can be first sign of impending scar rupture
• risks of scar rupture is higher in labours that are augmented or induced w/ prostaglandins or oxytocin

Question 13

In a breech presentation the caudal end of the fetus occupies the lower segment. Whilst around 25% of pregnancies at 28 weeks are breech it only occurs in 3% of babies near term.

What are the different types of breech presentation?

Answer 13

• A frank breech is the most common presentation with the hips flexed and knees fully extended
• A footling breech, where one or both feet come first with the bottom at a higher position, is rare but carries a higher perinatal morbidity

Question 14

What are the risk factors for breech presentation?

Answer 14

• uterine malformations, fibroids
• placenta praevia
• polyhydramnios or oligohydramnios
• foetal abnormality (eg. CNS malformation, chromosomal disorders)
• prematurity (due to increased incidence earlier in gestation)

Question 15

What are the risks/complications of breech presentation?

Answer 15

• cord prolapse (breech less effective as a “plug” in cervix)
• difficulty delivering head (“head entrapment”)
• foetal hypoxia due to head entrapment
• increased foetal mortality and morbidity (“term breech trial”)

Question 16

What is the management of breech?

Answer 16

• if <36 weeks, many foetuses will turn spontaneously
• if still breech at 36wks → NICE recommend ECV*
• if baby still breech then delivery options include planned caesarean section or vaginal delivery

*on next slide

Question 17

What is the success rate of external cephalic version (ECV)?

Answer 17

• offered @ 36wks in nulliparous women and 37-38wks in multiparous
• uterine relaxants often given prior to or during procedure (eg. terbutaline or salbutamol)
• foetal heart monitored w/ CTG pre + post procedure
• benefits → may prevent c-section or vaginal breech delivery + associated risks
• risks → foetal distress (cord entlanglement/retro-placental clot); sometimes transient
• emergency c-section rate 1:200
• success rate approx 50% (40% nulliparous; 60% multip)

Question 18

What do the RCOG recommend when providing information to help decision making, for management of breech pregnancies?

Answer 18

• ‘Women should be informed that planned caesarean section carries a reduced perinatal mortality and early neonatal morbidity for babies with a breech presentation at term compared with planned vaginal birth.’
• ‘Women should be informed that there is no evidence that the long term health of babies with a breech presentation delivered at term is influenced by how the baby is born.’

Question 19

What are the absolute contraindications to ECV?

Answer 19

• where caesarean delivery is required
• antepartum haemorrhage within last 7 days
• abnormal cardioctography
• major uterine anomaly
• ruptured membranes
• multiple pregnancy

Question 20

Postpartum haemorrhage (PPH) is defined as blood loss of > 500mls and may be primary or secondary.

What is primary postpartum haemorrhage?

Answer 20

• loss >500ml blood within 24hrs of delivery
• minor means 500-1000ml
• major means >1000ml
• massive obstetric haemorrhage means 1500ml+

Affects around 5-7% deliveries

Question 21

What is secondary postpartum haemorrhage?

Answer 21

• loss of excessive blood between 24hrs and 12wks following delivery
• due to retained placental tissue or endometritis

Question 22

What are the causes of primary PPH (4 Ts)?

Answer 22

• Tone - atonic uterus (most common)
• Tissue - retained placenta w/ prolonged third stage
• Trauma - vaginal or cervical tear
• Thrombin - associated w/ pre-eclampsia or DIC

Question 23

What are the risk factors for primary PPH?

Answer 23

• prev PPH
• prolonged labour
• pre-eclampsia
• increased maternal age
• polyhydramnios
• emergency C-Section
• placenta praevia, placenta accreta
• macrosomia
• ritodrine (a beta-2 adrenergic receptor agonist used for tocolysis)

Question 24

What is the management of PPH?

Answer 24

• ABC including 2x peripheral cannulae, 14G
• IV syntocinon (oxytocin) 10 units or IV ergometrine 500mcg
• IM carboprost
• if med options fail to control → surgical options urgently
• RCOG state intrauterine balloon tamponade is appropriate first-line ‘surgical’ intervention for most women where uterine atony is only or main cause of haemorrhage
• other options include: B-Lynch suture, ligation of uterine arteries or internal iliac arteries
• if severe, uncontrolled haemorrhage then a hysterectomy is sometimes performed as a life-saving procedure

Question 25

**Cord prolapse** involves the umbilical cord descending ahead of the presenting part of the fetus. This occurs in 1/500 deliveries. Left untreated, this can lead to compression of the cord or cord spasm, which can cause **fetal hypoxia** and eventually irreversible damage or death. What is the **management** of cord prolapse?

Answer 25

* majority occur at **artifical rupture of membranes** * diagnosis made when foetal HR becomes abnormal + cord palpable vaginally or if cord visible beyond level of introitus * **presenting part** of foetus may be **pushed back into uterus** to avoid compression * **tocolytics** may be used eg. terbutaline * if cord is _past_ level of introitus, it should be kept warm + moist but not pushed back inside * pt asked to go on **all 4s** until prep for an **_immediate C-section_** done * instrumental vaginal delivery possible if cervix fully dilated + head is low * if treated early, foetal mortality in cord prolapse is low * incidence reduced by increase in C-sections being used in breech presentations

Question 26

**Shoulder dystocia** refers to a situation where, after delivery of the head, the anterior shoulder of the fetus becomes impacted on the maternal pubic symphysis, or (less commonly) the posterior shoulder becomes impacted on the sacral promontory. It is an **obstetric emergency**, with an incidence of approximately 0.6-0.7% in all deliveries. What are the **clinical features** of shoulder dystocia?

Answer 26

**Shoulder dystocia** is defined by a delay in delivery of the shoulders following the head during a vaginal delivery with the next contraction after using normal traction. On examination, signs that may occur to aid the diagnosis are: * **Difficulty** in delivery of foetal head or chin * **Failure of restitution** - foetus remains in OA position after delivery by extension + therefore does not 'turn to look to side' * **'Turtle Neck' sign** - foetal head retracts slightly back into pelvis, so that neck is no longer visible, akin to a turtle retreated into its shell

Question 27

Complications of shoulder dystocia include 3rd/4th degree tears and PPH. To the foetus they include humerus or clavicle fracture, brachial plexus injury and hypoxic brain injury. What are the **immediate steps** in the **management** of shoulder dystocia?

Answer 27

* **_call for help_** * advise mother to **stop pushing** * **avoid downwards traction** on foetal head -- only use routine axial traction ie. keep head in line with baby's spine + do not apply fundal pressure * **consider episiotomy** - this will not relieve obstruction but can make access for maneouveres easier

Question 28

What are the **first-line manoeuvres** for shoulder dystocia?

Answer 28

* **McRobert's manoeuvre** → Hyperflex maternal hips (knees to chest position) + tell pt to stop pushing. This _widens_ pelvic outlet by flattening the sacral promontory + increasing lumbosacral angle. This single manoeuvre has success rate of **90%** + is even higher when combined with 'suprapubic pressure' * **Suprapubic pressure** → Applied in either a sustained or rocking fashion to apply pressure _behind_ anterior shoulder to disimpact it from underneath the maternal symphysis

Question 29

What are the **second-line** ('internal') manoeuvres?

Answer 29

* **Posterior arm** - insert hand posteriorly into sacral hollow + grasp posterior arm to deliver * **Internal rotation** ("**corkscrew manoeuvre**") - apply pressure simultaneously in front of one shoulder + behind the other to move baby 180 degrees or into an oblique position If above manoeuvres fail then roll patient onto all fours and repeat (this may widen the pelvic outlet as the legs are abducted and flexed)

Question 30

What are the **further manoeuvers** to be considered when the previous measures have been unsuccessful?

Answer 30

* **cleidotomy** → fracturing foetal clavicle * **symphysiotomy** → cutting pubic symphysis * **zavenelli** → returning foetal head to pelvis for delivery of baby via C-Section

Question 31

There are two main classifications of **premature membrane rupture** - _PROM_ and _P-PROM_. What is **PROM**?

Answer 31

* **premature rupture of membranes** (PROM) * rupture of foetal membranes at least **1hr prior** to onset of labour * at **_≥37 wks gestation_** * occurs in 10-15% of term pregnancies + is associated w/ _minimal_ risk to mother and foetus due to advanced gestation

Question 32

What is **P-PROM**?

Answer 32

* **pre-term premature rupture of membranes** (P-PROM) * rupture of foetal membranes occurring at **\<37weeks** gestation * complicates ~2% of pregnancies + has higher rates of maternal + foetal complications * associated w/ 40% of preterm deliveries

Question 33

Diagnosis of PROM or P-PROM is usually made by; (i) maternal history of membrane rupture and; (ii) positive examination findings. What are **clinical features** of premature rupture of membranes?

Answer 33

* **broken waters** → painless popping sensation w/ gush of watery fluid leaking from vagina * can be **gradual** leakage / damp underwear +/- change of consistency * speculum → fluid pooling in **posterior vaginal fornix** * for adequate examination, lie woman on bed for 30 mins to allow pooling to top of vagina * asking woman to cough can expel amniotic fluid ## Footnote *If suspecting PROM/PPROM → _AVOID performing digital vaginal exam_ until woman in active labour as otherwise this might stimulate labour to come quicker and increase risk of introducing ascending uterine infection*

Question 34

What is the **management** of PROM + PPROM?

Answer 34

Question 35

Describe how drug treatment of women in premature labour can help prevent respiratory distress syndrome of the newborn

Answer 35

* single course of **corticosteroids** for women between **24wks** and up to **34wks** gestation if at risk of preterm delivery in next 7 days * betamethasone + dexamethasone * may _consider_ in women at 23wks gestation who are at risk of preterm delivery within 7 days * single course of betametasone for pregnant women at risk of premature labour within 7 days, from **34 weeks' and up to 37 weeks'** gestation * optimal clinical benefit of antenatal corticosteroids is likely to be from 24 hours to 7-14 days after administration