Vaginal Delivery After Caesarean Section

(VBAC)Alicia Tan

101303513

Once a Caesarean, always a Caesarean?

Learning objectives

• Terms/definitions

• Evaluate the risks to mother and baby

• Evidence based for safe practice of VBAC

• Patient selection

• Preparation of patients

• Guidelines for intrapartum care

Terms

• VBAC

• Planned VBAC

• Successful/unsuccessful VBAC

• TOLAC (Trial of labour after Caesarean Section)

• Uterine rupture vs dehiscence

Rupture vs dehiscence

Case study I

• Puan X, a 28 year old factory worker from Ayer Keroh, Gravida 2, Para 1 presents to you at period of gestation of 24 weeks. Her 1st child was born 3 years ago via emergency LSCS due to prolonged 2nd stage of labour. She goes for regular check ups and does not have any complications (BP, MGTT, Hb, weight gain, etc- all normal)

• She wants your opinion regarding the mode of delivery of her present pregnancy.

What are the issues?

Questions from patient

• 1. Can I deliver via vaginal delivery?

• 2. What are the chances of failure?

• 3. What are the possible complications?

• to me (mother)

• my baby

• 4. Can I be given epidural?

Management

• ANTENATAL (history, counselling, timing of delivery)

• INTRAPARTUM (trial, scar dehiscence, induction/augmentation)

• POSTPARTUM

ANTENATAL COUNSELING

• Should be recorded in notes

• Final decision for mode of delivery decided between women and obstetrician ideally before 36 weeks of POG.

• Women should be informed of statistics (success rate: 72-76%)

• Factors associated with successful VBAC

• previous vaginal birth (esp:VBAC [87-90%])

ANTENATAL

• History

• Complete history of previous C-sec

• Screen for contraindications for VBAC

• Counseling

• 34-36w POA

• Time of Delivery

Risk in VBAC

• To mother

• To baby

Maternal Risk• UTERINE RUPTURE : disruption of the uterine muscle

extending to and involving the uterine serosa or disruption of the uterine muscle with extension to the bladder or broad ligament.

• UTERINE DEHISCENCE : disruption of the uterine muscle with intact uterine serosa.

• OTHERS: hysterectomy, thromboembolism, haemorrhage, transfusion requirement, viscus injury(bowel, bladder, ureter), endometritis,

• MATERNAL DEATH

FETAL OUTCOME TERM DELIVERY RELATED PERINATAL MORTALITY: combined number of intrapartum stillbirths and neonatal deaths per 10 000 live births and stillbirths, at or beyond 37 completed weeks of gestation. Birth- related perinatal mortality rates exclude antepartum stillbirths and deaths due to fetal malformation unless otherwise stated. (2-3/10 000)

1 HYPOXIC ISCHEMIC ENCEPHALOPATHY (HIE) : hypoxia resulting from a decrease in the blood supply to a bodily organ, tissue, or part caused by constriction or obstruction of the blood vessels, which results in compromised neurological function manifesting during the first few days after birth. HIE refers to a subset of the much broader category of neonatal encephalopathy, in which the aetiology is felt to be intrapartum hypoxic–ischemic injury. (8/10 000)

Risk Factors for unsuccessful VBAC

• induced labour

• no previous vaginal birth

• body mass index greater than 30

• previous caesarean section for dystocia

• When all these factors are present, successful VBAC is achieved in only 40% of cases

Other risk factors• VBAC at or after 41 weeks of gestation

• birth weight greater than 4000g

• no epidural anaesthesia

• previous preterm caesarean birth

• cervical dilatation at admission less than 4 cm,

• less than 2 years from previous caesarean birth

• advanced maternal age

• non-white ethnicity

• short stature

• male infant

Contraindications for VBAC

previous uterine rupture- risk of recurrent rupture is unknown

1 previous high vertical classical caesarean section (200–900/10,000 risk of uterine rupture)

2 where the uterine incision has involved the whole length of the uterine corpus

3 three or more previous caesarean deliveries (reliable estimate of risks of rupture unknown)

Classical C-section

INTRAPARTUM

• Trial of labour : 6-8 hours

• Signs of scar dehiscence/rupture

• Induction and Augmentation

Uterine Ruptureabnormal CTG

1 severe abdominal pain, especially if persisting between contractions

2 chest pain or shoulder tip pain, sudden onset of shortness of breath

3 acute onset scar tenderness

4 abnormal vaginal bleeding or haematuria

5 cessation of previously efficient uterine activity

6  maternal tachycardia, hypotension or shock

7  loss of station of the presenting part.

Augmentation of labour

• 2- 3 fold increased risk of uterine rupture

• 1.5 fold increased risk of caesarean section in induced and/or augmented labours compared with spontaneous labours

• higher risk of uterine rupture with induction of labour with prostaglandins

POST-PARTUM

• Continue vital sign monitoring

• Watch out for signs of dehiscence/rupture

4 key points

• Indications for Caesarean section (recurrent vs non-recurrent)

• Intrapartum/post operative complications (previous C-section)

• Reduced inter-delivery interval (less than 2 years)

• Complications in current pregnancy

Case Study II• Date: 01/06/2015, Time: 4:15pm

• 27 year old, POG: 40 weeks presented to labour room with contraction pains, 1 cm dilated and 25% effaced. Her history of present pregnancy is unremarkable.

• Past obstetric history: She delivered a healthy 3.0kg baby boy via Caesarean section (indication: breech presentation and oliohydramnios) 3 years ago

• At 9:15pm (5 hours later)

• She was 3 cm dilated, 70% effaced, and the fetus was at –1 station.

• At 9:30 pm, induction with oxytocin was started

• By 1 am (3.5 hours later), the patient's contractions were described as progressing from mild to moderate;

• by 1:10 am, they were occurring every 4 to 5 minutes.

• At 1:30 a.m. the fetal heart rate was in the 150s with adequate variability, and contractions were occurring every 3 to 4 minutes. The patient's cervix was 4 cm dilated and 80% effaced.

• At 1:35 am the oxytocin was discontinued and epidural anesthesia administered.

• Twenty minutes later, the oxytocin was resumed at 4 mIU.

• At 3:30 am the patient was contracting every 2 to 5 minutes, with occasional decelerations, and the oxytocin was being administered at 7 mIU.

• By 5 am, the patient's cervix was 5 cm dilated and 100% effaced, and a deceleration to 70 bpm occurred

• At which time the fellow, Dr. P, turned the patient on her left side and administered oxygen. At that time, the oxytocin infusion was at 6 mIU. At 5:40 am the nurse-midwife reported that contractions were difficult to pick up on the monitor.

• The patient's cervix was now 9 cm dilated and the fetus was at 0 station. The nurse-midwife's notation indicated that the physicians still anticipated a spontaneous vaginal delivery.

• At 6:15 am, two decelerations to 90 bpm were documented, lasting 40 seconds.

• At 6:23 am, two additional decelerations to 60 bpm were documented, and the patient was contracting every 3 minutes.

• At 6:40 am, there was another documented deceleration to 80 bpm for 10 seconds, and at 6:50 am, the epidural was turned off and the patient was encouraged to push.

• The FHR baseline was 145 bpm, with adequate variability.

• At 6:55 am, an additional deceleration to 50 bpm for 20 seconds was documented.

• At approximately 7:10 am, the nurse-midwife asked Dr. P to evaluate the patient because they were having "difficulties" with the internal monitor.

• Dr. P noted that the FHR was in the 50 to 60 bpm range and then attempted to replace the internal clip. After multiple "failed" attempts,

• Dr. P ordered placement of an external monitor. At 7:18 am, after placement of the external monitor, the FHR was noted to be in the 110 to 120 bpm range, with decelerations down to 50 to 60.

• At 7:20 am, the maternal pulse was 127 bpm, the FHR was 60 to 70 bpm, and uterine contractions were untraceable.

• At 7:25 am, the maternal pulse was 121 bpm, FHR was between 120 and 130, and the patient was advised that if the FHR decreased again, she would be taken for cesarean delivery.

• At 7:27 am, the maternal pulse was 127 bpm and the FHR was 120 to 130 bpm, with positive accelerations to 140, but uterine contractions were untraceable.

• At 7:40 am, Dr. P was uncertain about whether the monitor was tracing the maternal pulse or the FHR and called the attending, Dr. G, for evaluation. An internal electrode revealed the FHR at 55 bpm, and a stat C/S was called. The C/S was performed at 7:49 am and revealed a uterine rupture and complete placental abruption.

• The infant was delivered from the peritoneum, resuscitated by neonatology, and immediately transferred to the neonatal intensive care unit for further management. The initial arterial blood gas revealed a pH of 6.87. The infant experienced neonatal seizures and suffered profound developmental, cognitive, and neurologic disabilities.

Allegations

• The patient asserted that C/S should have been performed earlier and that a trial of labor was contraindicated, given her previous C/S for breech presentation, oligohydramnios, and the lack of information on the location of the prior uterine incision.

• She further alleged that the physicians were unaware of fetal distress and a significant deceleration in the FHR and mistakenly thought the mother's heart rate was that of the fetus.

• As a result, the plaintiffs alleged, the physicians failed to appreciate uterine rupture in a timely fashion so as to prevent significant fetal distress, and failed to have the attending obstetrician present throughout the course of this trial of labor.

Take home message

• Assessment of patient for VBAC

• Counseling of patients

• Intra-partum care

References

• RCOG GreenTop Guidelines

• Mayo Clinic

• http://www.arfdlaw.com/images/articles/obgyn_Jun_1_2004.pdf (When not to attempt VBAC)

• Guidelines and Protocols Dept of Ob/Gyn Hospital Melaka