Obstetric Topic 52. Obstetric operations. Cesarean section (indications)

I. Operative Vaginal Delivery

Definition, Indications and Prerequisites

• Operative vaginal delivery: forceps or vacuum assistance in the 2nd stage to achieve vaginal birth.
• Indications: prolonged 2nd stage, fetal distress/non-reassuring FHR, maternal exhaustion or maternal disease requiring shortened pushing, e.g. HF, eclampsia.
• Prerequisites: fully dilated cervix, ruptured membranes, engaged head, known position/station, no suspected CPD, empty bladder, adequate analgesia/anesthesia and skilled operator.

Forceps Delivery

• Mechanism: blades applied around fetal head/skull → traction ± rotation.
• Advantages: fast, lower failure than vacuum; can help after-coming breech head/selected non-vertex situations in expert hands.
• Disadvantages: requires more skill and anesthesia; more maternal genital tract trauma.
• Complications: maternal genital tract, bladder or rectal injury, PPH; fetal facial marks, cephalohematoma or rare nerve/skull injury.

Vacuum Extraction

• Mechanism: suction cup on fetal scalp → traction with contractions and maternal pushing.
• Cup placement: sagittal suture, about 3 cm anterior to posterior fontanelle.
• Advantages: less maternal injury and often no/less anesthesia.
• Contraindications: non-vertex presentation, face/brow/breech, unengaged/unknown position, suspected CPD, usually <34 weeks.
• Complications: cephalohematoma, subgaleal hemorrhage, retinal/subconjunctival bleeding, scalp injury.

II. Episiotomy and Cervical Cerclage

Episiotomy

• Episiotomy: surgical incision of perineum at crowning to enlarge vaginal outlet.
• Indications: rigid perineum, large fetus, fetal distress/need for rapid delivery, instrumental delivery.
• Timing: crowning, when the largest head diameter is encircled by the vulvar ring.
• Midline: simple repair, good healing, less bleeding/pain/dyspareunia; higher risk of 3rd/4th-degree extension.
• Mediolateral: harder repair, more pain/bleeding; lower risk of 4th-degree perineal tear.

Cervical Cerclage

• Circumferential suture around cervix to reduce preterm birth risk from cervical incompetence/insufficiency.
• Types: McDonald, Shirodkar; transabdominal cerclage in selected cases.
• Remove before labor, usually around 36-37 weeks or earlier if labor/PPROM.

III. Cesarean Section

Definition and Types

• C-section: delivery of fetus through abdominal and uterine incisions.
• Elective/planned/prophylactic: before labor to prevent expected complications.
• Emergency/vital: during labor or acute event to prevent immediate maternal/fetal danger.

Indications

• Prophylactic maternal: severe maternal illness, previous C-section/uterine scar, contracted pelvis/CPD, obstructing cervical tumor or fibroid.
• Prophylactic fetal: multiple pregnancy, macrosomia, malpresentation such as breech, selected fetal abnormalities.
• Prophylactic maternal-fetal: malposition, dystocia, CPD.
• Vital maternal: severe hemorrhage, DIC, eclampsia.
• Vital fetal: asphyxia/non-reassuring FHR/bradycardia, cord prolapse, transverse or brow presentation.
• Vital maternal-fetal: uterine rupture, placenta previa, placental abruption, eclampsia with IUGR, failed induction/progress.

Procedure

1. Anesthesia: usually spinal/epidural; general anesthesia for emergencies or contraindication/failed neuraxial block.
2. Abdominal wall incision: Pfannenstiel transverse suprapubic or vertical lower median.
3. Uterine incision: lower segment transverse, low vertical or classical/corporal vertical.
4. Deliver baby → clamp/cut cord.
5. Deliver placenta and membranes.
6. Close uterine and abdominal incisions.

Uterine Incisions

• Lower transverse: standard; less bleeding, better healing, lower future rupture risk.
• Low vertical: selected abnormal presentation/large fetus when transverse extension risk is high.
• Classical/corporal vertical: upper segment incision; highest future rupture risk.

IV. Complications and Exam Comparison

C-section Complications

• PPH, uterine atony, incision extension, anesthetic complications.
• Infection: endometritis, wound infection, sepsis.
• Thromboembolism: DVT/PE.
• Bowel, bladder or ureter injury.
• Future pregnancy risk: uterine rupture, placenta previa/accreta, adhesions and repeat cesarean morbidity.

Exam Comparison

• Forceps: faster, lower failure, more maternal injury, can help after-coming breech head.
• Vacuum: less maternal injury, requires maternal pushing, more cephalohematoma/subgaleal risk, vertex only, avoid preterm.
• C-section: safest route for many emergencies/malpresentations, but higher maternal surgical risk than uncomplicated vaginal birth.