Cesarean Section and Operative Vaginal Delivery

• Operative obstetrics involves methods to deliver a fetus beyond uterine contractions and maternal pushing, including vaginal (instrumental) or cesarean deliveries.

Operative Vaginal Birth

• Operative birth delivery is essential in modern obstetrics for achieving or expediting vaginal delivery.
• Operative delivery rates have declined, contributing to increased cesarean rates.

Benefits of Operative Vaginal Birth

• Avoids cesarean birth and related complications: hemorrhage, infection, prolonged healing, increased cost, repeat cesareans, and placental abnormalities in subsequent pregnancies.
• Can be accomplished quicker than cesarean birth.

Types of Instruments

• Vacuum extractors: easier to learn, can be used with asynclitism.
• Forceps: more secure application, appropriate for rotation.
  • Mid forceps
  • Low forceps
  • Outlet forceps

Forceps

• Obstetric forceps are metal instruments used to provide traction, rotation, or both to the fetal head.
• Types of Obstetric Forceps:
  • Simpson: used for traction only.
  • Kielland: used for head rotation and traction.
  • Piper: used for the after-coming head of a vaginal breech baby.
  • Barton: used to deliver the head in occiput transverse position with a platypelloid pelvis.

Forceps Classification

• Outlet: fetal head on pelvic floor (most common use).
• Low: fetal head below +2 station but not yet on pelvic floor.
• Mid: fetal head below 0 station but not reached +2 station (seldom used today).
• High: fetal head unengaged, above 0 station (never appropriate due to risks).

Forceps Indications

• Prolonged second stage: due to dysfunctional labor or suboptimal fetal head orientation (most common).
• Category III EFM strip: fetal heart rate monitor pattern suggests fetus is not tolerating labor.
• Avoid maternal pushing: conditions where pushing is hazardous (cardiac, pulmonary, neurologic disorders).
• Breech presentation: to shorten delivery time for the fetal head.

Forceps Prerequisites

• Cervix fully dilated and retracted.
• Membranes ruptured.
• Engagement of the fetal head.
• Position of the fetal head determined.
• Fetal weight estimation performed.
• Pelvis adequate for vaginal birth.
• Adequate anesthesia.
• Maternal bladder emptied.
• Patient agreement after informed consent on risks/benefits.
• Willingness to abandon operative vaginal birth with a backup plan for failed delivery.

Forceps 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.

Forceps Complications

• Fetal: Neonatal jaundice, Scalp lacerations, Cephalhaematoma, Subgaleal hematoma, Facial bruising, Facial nerve damage, Skull fractures, Retinal hemorrhage
• Maternal: Vaginal tears, 3rd/4th degree perineal tears, VTE, Incontinence, PPH, Shoulder dystocia, Infection

Further Considerations

• Estimated Fetal Weight: Judicious use in suspected macrosomia, consider pelvic adequacy and labor progress.
• Episiotomy: Should not be routinely performed.
• Prophylactic Antibiotics: Not routinely suggested.
• Trial of Operative Vaginal Delivery: Performed by experienced provider with cesarean services readily available.

Vacuum Extractor

• A cuplike instrument held against the fetal head with suction.
• Traction on the fetal scalp, along with maternal pushing efforts, leads to descent of the head and vaginal delivery.
• Cups can be metal or plastic, rigid or soft.
• The ventouse cup is applied over the flexion point on the fetal skull, 3cm anterior to the posterior fontanelle.
• Traction is applied perpendicular to the cup during uterine contractions.
• Ventouse deliveries are associated with lower success rate, less maternal perineal injuries and less pain. There is more cephalhaematoma, subgaleal hematoma, and fetal retinal haemorrhage.

Advantages of Vacuum Extractor Over Forceps

• Fetal head orientation: Precise knowledge of fetal head position and attitude not essential.
• Space required: Does not occupy space adjacent to the fetal head.
• Perineal trauma: Fewer third- and fourth-degree lacerations.
• Head rotation: Fetal head rotation occurs spontaneously at the station best suited to fetal head configuration and maternal pelvis.

Disadvantages of Vacuum Extractor Over Forceps

• Cup pop-offs: Excessive traction can lead to sudden decompression as the cup suction is released.
• Scalp trauma: Scalp skin injury and lacerations are common.
• Subgaleal hemorrhage and intracranial bleeding are rare.
• Neonatal jaundice arises from scalp bleeding.

Vacuum Extractor Indications

• Similar to those of forceps: Prolonged second stage, Non-reassuring EFM strip, Avoid maternal pushing.

Vacuum Extractor Prerequisites

• Clinically adequate pelvic dimension.
• Experienced operator.
• Full cervical dilation.
• Engaged fetal head.
• Gestational age ≥34 weeks.

Vacuum Extractor Complications

• Maternal vaginal lacerations from entrapment of vaginal mucosa between the suction cup and fetal head
• risk of neonatal cephalohematoma and scalp lacerations (common), and life-threatening complications of subgaleal hematoma or intracranial hemorrhage (uncommon but associated with vacuum duration >10 min)

Cesarean Section

• It involves delivering the fetus through incisions in the maternal anterior abdominal and uterine walls.
• Overall U.S. cesarean section rate in 2011 was ~33% (includes both primary and repeat procedures).

Risks of Cesarean Sections

• Maternal mortality and morbidity are higher than with vaginal delivery, especially with emergency cesareans.
• Maternal mortality is largely anesthetic-related.
• Overall mortality ratio of 25 per 100,000.
  • Hemorrhage: Blood loss is doubled compared to vaginal delivery.
  • Mean blood loss is 1,000 mL. -Infection: Sites of infection include endometrium, abdominal wall wound, pelvis, urinary tract, or lungs.
  • Prophylactic antibiotics can decrease infectious morbidity.
  • Visceral injury: Surrounding structures can be injured (e.g., bowel, bladder, and ureters).
  • Thrombosis: Deep venous thrombosis is increased in the pelvic and lower extremity veins.

Uterine Incisions

• Low segment transverse: Made in the noncontractile portion of the uterus (most common).
  • The bladder is dissected off the lower uterine segment.
  • Low chance of uterine rupture in subsequent labor (0.5%).
    • Advantages: Trial of labor in a subsequent pregnancy is safe.
    • Risk of bleeding and adhesions is less. -Disadvantages: Fetus(es) must be in longitudinal lie; the lower segment must be developed.
• Classical: Made in the contractile fundus of the uterus.
  • Technically easy to perform, and does not require bladder dissection.
  • Significant risk of uterine rupture before and during subsequent labor (5%).
    • Repeat cesarean should be scheduled before labor onset.
      • Advantages: Any fetus(es) regardless of intrauterine orientation can be delivered.
      • Lower segment varicosities or myomas can be bypassed.
        • Disadvantages: Trial of labor in a subsequent pregnancy is unsafe.
        • Risk of bleeding and adhesions is higher.

Indications for Primary Cesarean Section

• Cephalopelvic disproportion (CPD): The pelvis too small for the fetal head (most common indication).
• Failure of adequate progress in labor: May be related to dysfunctional labor or suboptimal fetal head orientation.
• Fetal malpresentation: Breech or any non-cephalic fetal orientation.
• Category III EFM strip: FHR monitor pattern suggests the fetus may not be tolerating labor, but commonly this is a false-positive finding.

Elective Cesarean Recommendations

• Women should be counseled individually for risks and benefits.
• Women considering having greater than 2 children should be aware that a cesarean section causes uterine scarring. It is advised they should avoid a primary cesarean section.
• Women should not have a cesarean section before 39 weeks' gestation.