Instrumental Delivery: Techniques and Insights

Instrumental delivery is defined as vaginal delivery done with the assistance of instruments. These instruments can be vacuum or forceps. Indications like fetal distress or abnormal position are responsible for the need of Instrumental delivery.

Instrument Types

Forceps

• Parts:
  • 2 branches
  • Blade- It has toe, tip and base.
  • Handle
  • Shank in-between
  • Locks on forceps are present to avoid the slipping while applying traction.
• Classification of Forceps:

1. Traction Forceps
   • Short : Wrigley’s outlet forceps.
   • Long: Simpson’s forceps for +2 stations.
2. Rotation Forceps
   • Kielland for occipito transverse
3. Special Forceps
   • Piper’s for after coming head.

Examples of Forceps

1. Simpsons Forceps
   • Long forceps, max distance between blades is 8.5cms and it has long handles.
   • Used for +2 station deliveries.
2. Wrigley’s Forceps
   • Length is 27.5 cms
   • Light short forceps.
   • For low outlet forceps
   • English lock

Applications of Forceps

• Forceps should be assemble in front of the patient , keep pelvic curve up.
• Left blade placed first.
• Hold forceps in left hand like a pen.
• Slip blade over your right hand which is placed inside the vagina.
• Wandering methods for the application of forceps are Kiellands rotational forceps and SImpsons forceps.
• Direct method is used for Wrigley’s outlet forceps.

Vacuum /Ventouse Cups

1. Silastic cups
   • These donot slip on application.
   • These are better for outlet procedures.
2. Metallic Cups
   • It is an old and traditional cumbersome to use.
   • Classical size is 5cm and it is used for traction.
   • It is 6 cm for occipito-posterior.
   • It has a Rotational application. It is good to rotate the head of the baby

Application of Vacuum Cups

• Suction cup is applied on fetal head.
• A pressure of upto 0.8kg/sq.cmis built slowly within 2-8 minutes.
• Swelling on the head is formed after vacuum usage called as Chignon.
• The vacuum cup is applied on the head over the saggital suture.
• There is a 2-3cm in front of the posterior fontanelle called as Flexion point.

Instrument Delivery Indications

1. Fetal indications:
   • Fetal distress in the second stage
   • Passage of meconium
   • Fetal scalp blood pH<7.2
   • Persistent type 2 decelerations
   • Forceps are used in case of cord prolapse forceps should be used.
2. Maternal indications:
   • It is done mainly to reduce the duration of the second stage of labour.
   • Pre-eclampsia
   • Heart disease
   • Severe anemia 
   • Maternal exhaustion

Pre-Requisites for Instrumentation

• Consent for procedure
• Empty bladder
• Adequate pelvis
• Good uterine contractions
• Station +2 or lower
• Head<1/5th palpable per abdomen
• Membranes ruptured
• Adequate anesthesia
• Facility of emergency LSCS available

Complications

1. Complications of Forceps:

• Maternal Complications:
  • Vaginal and Cervical lacerations.
  • Traumatic PPH
  • Bladder and Urethral injury.
  • Nerve injuries with mid forceps like the femoral nerve.
  • Pelvic hematoma.
• Fetal Complications:
  • Lacerations or bruising of the fetal scalp and skull.
  • Intracranial hemorrhage
  • Cephalohematoma
  • Skull fracture
  • Facial and Erb’s Palsy

2. Complications of Vacuum:

• Maternal Complications
  • Vaginal hematoma
  • Vaginal and cervical lacerations
  • Extension to third-degree perineal tears
  • Annular detachment of cervix
  • Traumatic PPH
• Fetal Complications
  • Scalp abrasions and sloughing
  • Cephalohematoma
  • Subaponeurotic hematoma
  • Intracranial hemorrhage
  • Retinal hemorrhage
  • Neonatal Jaundice 
• Caput Succedaneum
  • Soft tissue edema
  • Ill-defined border
  • Present at birth
  • Extends across suture lines
  • Does not increase in size
  • Disappears over 48 hours
• Cephalohematoma
  • Blood subperiosteal hemorrhage
  • Limited by suture lines
  • Gradually increases in size
  • Resolves in few weeks

Also Read: Puerperium: Understanding the Postpartum Period

Hope you found this blog helpful for your Obstetrics for OBS-GYN preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.