Instrumental Delivery

Overview

Author Information

By dr. Mona Ahmed

LEARNING OUTCOMES

When you have completed this tutorial you will be able to:

• decide when an instrumental delivery is needed
• decide which instrument is appropriate
• appreciate the techniques required for vacuum and forceps delivery
• recognise the complications associated with instrumental delivery
• know when to abandon the procedure.

KEY LEARNING POINTS

• OVD should be classified according to the position and station of the presenting part.
• Clinical assessment and confirmation that the safety criteria have been met are prerequisites for OVD.
• Vacuum or forceps may be suitable depending on the clinical circumstances and operator’s preference.
• OVDs with a higher chance of failure should be conducted in an operating theatre.
• Contingency planning is an essential part of any OVD.
• Anticipation and early management of maternal and neonatal complications is essential.
• Caesarean

Obstetric Instruments

• Obstetric forceps.

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• Obstetric vacuum.

Choice of Instruments

• Conditions where ventouse would be

  • Urgent low lift-out delivery.
  • Rotational delivery.
  • Operator or maternal preference.

• Conditions where forceps would be preferred to ventouse

  • Poor maternal effort.
  • Operator or maternal preference.
  • Large caput.
  • Gestation of less than 34 weeks (at 34–36 weeks of gestation, ventouse is relatively contraindicated).
  • After-coming head of the breech

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1. Obstetric Forceps

Definition:

• An instrument to offer traction and/or rotation of the Fetal head when the mother’s expulsive efforts are not sufficient to accomplish a safe delivery of the fetus

Types of Obstetric Forceps:

1. Short curved or Wrigley’s forceps
2. Long curved or Simpsons forceps
   • For traction only in breech vaginal delivery
3. Long straight or Kiellands forceps
   • For rotation and traction when the head is above 0 station.
4. Piper forceps: for the after-coming head in a vaginal breech baby

Indications for Forceps Delivery

1. Maternal:

• Dangers for the mother (e.g., prophylactic forceps in heart diseases):
• Toxaemia of pregnancy (pre-eclampsia & eclampsia).
• Weakness in the abdominal wall (e.g., hernias).
• Maternal distress.

2. Fetal:

• Prophylactic forceps (Dangers for the fetus) as in the case of Cord prolapse.
• Abnormal presentations & position:
  • Occipito-posterior, deep transverse arrest, face presentation & after-coming head.
• Fetal distress.

3. Prolonged 2nd Stage of Labor:

• 2 hrs in multipara or 3 hrs in primigravidae.
  • Can be used in C-section to pick the head up

Pre-requests for Forceps Delivery:

• Cephalic presentation (Piper forceps for after-coming head)
• Head is engaged.
• A fully dilated cervix.
• Ruptured membranes.
• Empty bladder & rectum.
• Adequate Anaesthesia.
• Adequate pelvis.
• Episiotomy.
• Make sure you lock the device before using it.
• Experienced operator

Complications of Forceps Delivery

A. Maternal:

• Traumatic lesions of the lower uterine segment, cervix, vagina & perineum.
• Sepsis.
• Obstetric shock.
• Bone injuries: Separation of the symphysis.
• Dislocation of the Sacro-iliac joint.
• Fracture of the coccyx or its dislocation.
• Post-partum haemorrhage (traumatic or atonic).
• Vesico-vaginal fistula & stress incontinence.

B. Fetal:

• Soft tissue compression
• Cranial injury due to incorrectly placed forceps

Contraindication:

• History of cephalo-pelvic disproportion

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The Vacuum Extractor or Ventouse

Definition:

• A cup-like instrument held against the fetal head to aid delivery under suction.

Types:

• Metal cup ventouse
• Plastic cup ventouse

Write the type of the ventouse in the exam.

Prerequisites for Vacuum Extraction:

• Clinically adequate pelvic dimensions
• Experienced operator
• Cervix fully dilated
• Engaged Fetal head
• Gestational age greater than 34 weeks

Fetal head direction not important.

Indications for Vacuum Extraction:

All the indications of forceps delivery EXCEPT:

• Face presentation
• After-coming head in breech.
• It can be utilized to remove the head out of a lower uterine segment C-section.

Contraindications for Vacuum Extraction:

• Face, breech & transverse presentation of the after-coming head.
• Premature babies.
• Moderate or severe cephalo-pelvic disproportion
• Fetal & maternal distress that requires immediate delivery
• After three failures immediately C/S

Complications:

• Increase the risk of cervical incompetence.
• Vaginal laceration.
• Fetal skull injuries: Cephalohematoma, Intracranial haemorrhage, scalp lacerations, necrosis & alopecia.

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