Forceps

• Operative vaginal delivery


  Accomplished by using either FORCEPS or VACUUM
• Most important function of forceps and vacuum

  • TRACTION
• Forceps may also be used for

  • ROTATION, particularly from occiput transverse and posterior positions
• Maternal indications for operative vaginal delivery

  • Exhaustion and prolonged second-stage labor (most common)
  • Heart disease
  • Pulmonary injury or compromise
  • Intrapartum infection
  • Certain neurological conditions
• Fetal indications for operative vaginal delivery

  • Nonreassuring fetal heart rate pattern
  • Premature placental separation
• High forceps


  Instruments applied above 0 station, have no place in contemporary obstetrics
• Prerequisites for operative vaginal delivery

  • Experienced operator
  • Engaged head
  • Ruptured membranes
  • Vertex presentation
  • Fully dilated cervix
  • Precisely assessed fetal head position
  • Cephalopelvic disproportion not suspected
  • No fetal coagulopathy or bone demineralization disorder

  
• Vacuum extraction


  Fetuses should be at least 34 weeks gestational age
• Analgesia/anesthesia for operative vaginal delivery

  Regional analgesia or general anesthesia is preferable for low forceps or midpelvic procedures, although pudendal blockade may prove adequate for outlet forceps

  
• Before operative vaginal delivery

  Bladder should be emptied to provide additional pelvic space and minimize bladder trauma
• Maternal morbidity from operative vaginal delivery

  • Lacerations (perineal, vaginal, cervical)
  • Pelvic floor disorders (urinary incontinence, anal incontinence, pelvic organ prolapse)
• Episiotomy


  Can lower the incidences of 3rd and 4th degree lacerations
• Perinatal morbidity from operative vaginal delivery

  • Cephalhematoma, subgaleal hemorrhage, retinal hemorrhage, neonatal jaundice secondary to these hemorrhages, shoulder dystocia, clavicular fracture, scalp lacerations
  • Higher rates of facial nerve injury, brachial plexus injury, depressed skull fracture, and corneal abrasion with forceps-assisted vaginal delivery
• Trial of operative vaginal delivery

  If an attempt to perform an operative vaginal delivery is expected to be difficult, then it should be considered a trial. If forceps cannot be satisfactorily applied, then the procedure is stopped and either vacuum extraction or cesarean delivery is performed.

  
• Factors associated with operative delivery failure

  • Persistent occiput posterior position
  • Absence of regional or general anesthesia
  • Birthweight > 4000 g
• Forceps design


  • Consists of 2 crossing branches, each with 4 components: blade, shank, lock, handle
  • Each blade has 2 curves: cephalic curve to conform to the round fetal head, and pelvic curve to correspond to the axis of the birth canal

  
• English lock


  Consists of a socket located on the shank at the junction with the handle, into which fits a socket similarly located on the opposite shank
• Sliding lock


  Used in Kielland forceps
• Types of forceps


  • Simpson or Elliot forceps with fenestrated blades
  • Tucker-McLane forceps with thin smooth blades

  
• Forceps blades


  • Each blade has 2 curves:
  • Cephalic curve - conforms to the round fetal head
  • Pelvic curve - corresponds to the axis of the birth canal

  
• Simpson or Elliot forceps


  • With fenestrated blades
  • Used to deliver a fetus with a molded head, as is common in nulliparous women
• Tucker-McLane forceps


  • Have thin smooth blades
  • Used for a fetus with a rounded head, which is more characteristic in multiparas
  • The fetal head is perfectly grasped only when the long axis of the blades corresponds to the occipitomental diameter and the forceps are applied directly to the sides of the fetal head

  
• For the occiput anterior position, appropriately applied blades are equidistant from the sagittal suture, and each blade is equidistant from its adjacent lambdoidal suture

  
• In the occiput posterior position, the blades are equidistant from the midline of the face and brow
• Vacuum delivery technique


  Suction is created within a cup placed on the fetal scalp such that traction on the cup aids fetal expulsion

  
• Vacuum extractor


  Also called a ventouse, contains a cup, shaft, handle, and vacuum generator
• Advantages of vacuum over forceps

  • Simpler requirements for precise positioning on the fetal head
  • Avoidance of space-occupying blades within the vagina, thereby lowering maternal trauma rates
• An important step in vacuum extraction is proper cup placement over the flexion point
• Placement of the cup more anteriorly on the fetal cranium—near the anterior fontanel—should be avoided as it leads to cervical spine extension during traction unless the fetus is small
• The entire cup circumference should be palpated both before and after the vacuum has been created as well as prior to traction to exclude maternal soft tissue entrapment
• Gradual vacuum creation


  Increasing the suction in increments of 0.2 kg/cm2 every 2 minutes until a total negative pressure of 0.8 kg/cm2 is reached
• Traction during vacuum delivery

  Initially directed downward, then progressively extended upward as the head emerges