Operative Vaginal Birth: Indications and Clinical Considerations

SUMMARY:

Operative birth delivery is an important component of modern obstetrics. Its purpose is to achieve or expedite a vaginal delivery. The rate of operative deliveries has significantly decreased in the last two decades, accounting for part of the increase in cesarean delivery rates in the United States.

Overview

Types of Instruments

• Vacuum: believed to be easier to learn and may be used with asynclitism
• Forceps: more secure application and appropriate for rotation
  • Mid forceps
  • Low forceps
  • Outlet forceps

Indications

• Prolonged second stage
• Suspicion of immediate or potential fetal compromise
• Shortening of the second stage of labor for maternal benefit

Contraindications

• Fetal head unengaged
• Position of the head is unknown
• Known or strongly suspected fetal bone demineralization condition or bleeding disorder
• Lack of experienced provider

Benefits

• Avoids cesarean birth and its associated complications
  • Hemorrhage | Infection | Prolonged healing time | Increased cost | Likelihood of repeat cesarean birth and associated placental abnormalities in subsequent pregnancies
• Can be accomplished quicker than cesarean birth

Complications

Maternal

• Higher rates of anal sphincter injuries with operative vaginal birth compared to spontaneous vaginal birth
• Forceps is more likely to achieve vaginal birth than vacuum but is more likely to be associated with third- and fourth- degree perineal tears
• Anal incontinence
  • More common at 6 weeks postpartum but no difference by 1 year
  • If no anal laceration, rates are similar to spontaneous vaginal birth at 5 to 10 years after delivery
• Sexual function scores and pelvic floor function
  • No difference at 1 year postpartum when compared to clinical alternative second stage cesarean birth

Neonatal

• Absolute rate of newborn injury with operative vaginal birth is low
• Some injuries are associated with the indication for delivery | Risk is not lessened by cesarean birth
• Vacuum extraction is associated with higher risks for
  • Laceration | Cephalohematoma | Subgaleal or intracranial hemorrhage | Retinal hemorrhages | Hyperbilirubinemia
• Forceps is associated with higher risks
  • Facial lacerations | Facial nerve palsy | Corneal abrasions | External ocular trauma | Skull fracture | Intracranial hemorrhage
• No differences between forceps and vacuum for
  • Umbilical artery pH | Severe morbidity | Death
• Long-term outcomes
  • Equivalent to those of spontaneous vaginal delivery
  • No difference in cognitive development, scholastic performance, speech, neurological abnormality

Note: Rate of neonatal death is similar for spontaneous vaginal delivery, cesarean delivery, forceps, or vacuum

Requirements for Operative Vaginal Birth

• Cervix fully dilated and retracted
• Membranes ruptured
• Engagement of the fetal head
• Position of the fetal head has been determined
• Fetal weight estimation performed
• Pelvis thought to be adequate for vaginal birth
• Adequate anesthesia
• Maternal bladder has been emptied
• Patient has agreed after being informed of the risks and benefits of the procedure
• Willingness to abandon trial of operative vaginal birth and back-up plan in place in case of failure to delivery

Further Considerations

Estimated Fetal Weight

• Judicious use of operative vaginal delivery with suspected macrosomia
• Injury Rates
  • Higher rate of injury in infants >4000g vs lower weights
  • No different than infants >4000 g with spontaneous vaginal delivery
• Consider adequacy of pelvis, progress of labor during second stage
  • Prepare for the increased possibility for shoulder dystocia

Episiotomy

• Episiotomy should not be routinely performed with operative vaginal delivery
  • Mediolateral – poor healing and prolonged discomfort
  • Midline – injury to anal sphincter and extension into the rectum

Prophylactic Antibiotics

• Routine prophylactic antibiotics before operative vaginal delivery are not suggested
• Reasonable at operative vaginal delivery with episiotomy or if third- or fourth- degree laceration occurs (see ‘Related ObG Entry’ regarding ANODE Trial)

Trial of Operative Vaginal Delivery

• An attempt of operative delivery is appropriate when the provider feels chances of success are high and is prepared to abandon procedure if descent does not occur
• Should be performed by experienced provider and have cesarean services readily available
• Insufficient data to establish number of forceps pulls or vacuum detachments before abandoning

KEY POINTS:

• Operative vaginal delivery with forceps or vacuum is safe and effective
  • Overall risk of neonatal injuries is low
  • Choice of whether to use vacuum or forceps is defined by clinical circumstances and operator preference
• Confirm appropriate placement before applying traction
  • Vacuum: 2 cm anterior to posterior fontanelle and centered over sagittal suture |Ensure no maternal tissue is included
  • Forceps: Sagittal suture aligned with shanks, posterior fontanelle one finger above shanks | Lambdoid sutures equidistant from forceps blades
• Neonatal care providers should be made aware of mode of delivery to assess for potential complications
• Operator should be prepared to abandon procedure if met with dangerous resistance or high difficulty and perform emergency cesarean delivery
• Sequential use of forceps and vacuum should not be routinely performed
  • Higher rates of neonatal morbidity and perineal injuries
• Pliable cup is associated with decreased fetal scalp trauma but increased risk of detachment
  • No differences in neonatal morbidity when comparing rigid and soft cup
• Cephalohematoma formation is more likely to occur with longer duration of vacuum traction
• Release of vacuum pressure between contractions does not appear to be associated with improved maternal or neonatal outcomes
• Midforceps and rotational forceps are appropriate in select clinical circumstances
• There may be a benefit from an attempt at rotation to occiput anterior from occiput posterior with arrest of descent
  • No difference in neonatal outcomes but higher rate of severe perineal laceration with forceps without attempt at rotation
• Vacuum < 34 weeks has been discouraged, although a lower gestational age limit has not been established

Learn More – Primary Sources:

ACOG Practice Bulletin Operative Vaginal Birth