#219 Operative Vaginal Birth Flashcards
What % of deliveries are operative vaginal deliveries?
3.3%
What are some indications for operative vaginal delivery?
Prolonged second stage of labor, suspicion of immediate or potential fetal compromise, shortening of the second stage of labor for maternal benefit
What are criteria for outlet forceps?
- Fetal scalp visible at introitus without separating the labia
- Fetal skull has reached pelvic floor
- Fetal head is at or on perineum
- Sagittal suture is in an anteroposterior diameter or right or left OA or posterior position
- Rotation does not exceed 45 degrees
What are criteria for low forceps?
- Leading point of fetal skull is at +2cm or more and not on the pelvic floor
- Without rotation: rotation is 45 degrees or less (right or left occiput anterior to occiput anterior, or right or left occiput posterior to occiput posterior)
- With rotation: rotation is greater than 45 degrees
What are criteria for midforceps?
Station is above +2cm, but head is engaged
Is vacuum extraction or forceps believed to be easier to learn?
Vacuum
Is a vaginal birth more likely to be achieved with forceps or vacuum extractors?
Forceps (RR 0.65)
Is vacuum or forceps associated with high risk of third or fourth degree perineal tears?
Forceps (RR 1.89)
Is vacuum or forceps more likely to be associated with neonatal cephalohematomas?
No difference
Is forceps or vacuum more associated with long-term urinary incontinence or anal sphincter?
No difference
At what gestational age can you use vacuum for delivery? Forceps?
Vacuum extraction discouraged <34wks (although a safe lower limit not established); no limit for forceps
What are prerequisites 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 emptied
- Informed consent, willingness to abandon trial and back-up plan in place in case of failure
Where should vacuum be placed on fetal head?
2cm anterior to the posterior fontanelle and centered over the sagittal suture, ensuring that no maternal tissue is included
How should forceps be applied?
Sagittal suture aligned with shanks, posterior fontanelle is one finger breadth above the shanks, and that the lambdoid sutures are equidistant from the forceps blades.
True or false, episiotomy should be routinely performed for operative vaginal deliveries
False
What are the risks/benefits of mediolateral episiotomy compared to midline episiotomy?
Lower risk of anal sphincter injury, increased likelihood of long-term perineal pain and dyspareunia
Does a vacuum or forceps delivery have a higher risk of anal sphincter injury?
Forceps
What is the difference in bowel or urinary dysfunction 5 years postpartum between women who had vacuum vs forceps assisted vaginal deliveries?
No difference
True or false, absolute rate of newborn injury with forceps and vacuum deliveries is low?
True
One in how many operative vaginal deliveries result in intracranial hemorrhage? One in how many result in neurologic complications?
1 in 650-850 for ICH.
1 in 220-385 with neurologic complications. (some question as to whether these outcomes are due to indication for operative delivery rather than delivery itself)
What neonatal injuries/complications have been reported with vacuum delivery?
Laceration, cephaliohematoma, subgaleal, ICH, retinal hemorrhage, increased hyperbilirubinemia
What neonatal injuries/complications have been reported with fprceps delivery?
facial lacerations, facial nerve palsy, corneal abrasions and external ocular trauma, skull fracture, ICH.
What is the rate of neonatal encephalopathy per 1,000 term neonates after operative vaginal birth compared to cesarean birth?
- 2 per 1,000 in operative vaginal delivery.
3. 9 per 1,000 in cesarean delivery
Is suspected macrosomia a contraindication to operative vaginal delivery?
No
What are contraindications to operative vaginal delivery?
Fetal head is unengaged, positional of fetal head is unknown, live fetus is known or strongly suspected to have a bone demineralization condition (eg, osteogenesis imperfecta), or a bleeding disorder (eg, hemophilia or von Willebrand)
What is the failure rate of operative vaginal deliveries?
2.9-6.5%
What factors are significantly associated with failure of operative vaginal delivery (when controlling for operator experience)?
Birth weight and second stage labor duration
What is the neonate at increased risk for after cesarean section after failed operative delivery?
Increased rates of subdural or cerebral hemorrhage, mechanical ventilation, and seizures
How many forceps pulls or vacuum detachments are allowed prior to moving to cesarean section?
No adequate data to generate evidence-based guidelines. Descent should be expected with traction, if no descent with first several pulls, a reappraisal is necessary
Compared with single operative vaginal delivery device alone, what does a combo of forceps and vacuum increase the risk of?
higher rates of subdural or cerebral hemorrhage, subarachnoid hemorrhage, facial nerve injury, and brachial plexus injury, severe perineal lacerations/sphincter tears, lower umbilical artery pH
What is most significantly associated with increased risk of cephalohematoma after vacuum assisted delivery?
Application time. 28% for those with application time >5 mins.
What is the rate (%) of cephalohematoma in neonates with vacuum application >5 minutes?
28%
During vacuum operative delivery, does reducing vacuum pressure between contractions decrease the rate of fetal scalp injury? Improve outcomes?
No x 2
What are Kielland forceps used for?
Rotational operative deliveries
Comparing Kielland forceps delivery to emergency cesarean delivery in second stage of labor, which has higher rates of NICU admission? Other measures of neonatal morbidity?
no difference
How do outcomes compare to forceps delivery in OP position compared to forceps delivery after either forceps or manual rotation to OA?
Forceps delivery without rotation has higher rate of severe perineal laceration (OR 3.67)
Should antibiotics be given at the time of operative delivery?
Not necessarily. But may consider if a 3rd or 4th degree laceration occurs
