Obstetric Topic 27. Breech presentation

I. Definition and Risk Factors

Definition

• Breech presentation: longitudinal lie where the buttocks, feet or knees present at the pelvic inlet.
• Incidence at term: about 3-4% of deliveries.
• Common earlier in pregnancy; most fetuses turn to vertex by 36-37 weeks.
• Main danger: the largest part (head) is delivered last → risk of head entrapment, hypoxia and birth trauma.

Risk Factors

• Prematurity / low birth weight: most important risk factor.
• Uterine factors: uterine anomaly, fibroid, abnormal uterine shape, multiparity.
• Fetal factors: hydrocephalus, anencephaly, other anomalies limiting normal vertex presentation.
• Placental / fluid factors: placenta previa, polyhydramnios or oligohydramnios.
• Other: multiple pregnancy, contracted pelvis/pelvic tumor, previous breech delivery.

II. Types and Diagnosis

Types

• Frank breech: hips flexed, knees extended, feet near the head; best candidate if vaginal breech delivery is selected.
• Complete breech: hips flexed and knees flexed.
• Incomplete / footling breech: one or both feet/knees present below the buttocks; high cord prolapse risk.

Diagnosis

• Leopold maneuvers: hard fetal head in the fundus, soft breech in the lower uterine segment.
• Fetal heart sounds often heard higher in the uterus.
• Vaginal examination during labor: buttocks, anus, sacrum, foot or knee may be palpated.
• Ultrasound confirms presentation and type; also checks fetal head flexion, anomalies, placenta, fetal weight and amniotic fluid.

III. Management

Antenatal Management

• If breech persists after 34-36 weeks → detailed US for fetal/uterine anomalies and delivery planning.
• External cephalic version (ECV): manual turning to vertex under US guidance, usually after 36-37 weeks and before/early labor.
• ECV should be performed in hospital with fetal monitoring, IV access and immediate cesarean capability.
• ECV success is about 50%; tocolysis may improve success.
• Do not perform ECV if cesarean is already required, fetal testing is abnormal, membranes are ruptured, recent bleeding/abruption is suspected, placenta previa is present, or there is a major contraindication to vaginal birth.

Mode of Delivery

• Persistent term singleton breech: planned cesarean is standard in many practices because neonatal risk is lower.
• Planned vaginal breech delivery may be considered only with strict local protocol, informed consent and an experienced operator.
• Favorable criteria: frank or complete breech, flexed fetal head, reassuring fetal status, adequate pelvis, estimated fetal weight about 2500-3800 g, gestational age >36-37 weeks, immediate cesarean/anesthesia/neonatal support available.
• Prefer cesarean for footling/incomplete breech, hyperextended head, fetal distress, placenta previa, clear CPD/contracted pelvis, macrosomia, very preterm fetus, or failed ECV.

IV. Vaginal Breech Delivery and Complications

Vaginal Breech Principles

• Avoid traction before the fetus delivers to the umbilicus; premature traction can extend the arms/head.
• After the umbilicus appears, check the cord and keep it loose; monitor fetal heart rate continuously.
• Assisted breech delivery: fetus delivers spontaneously to the umbilicus, then maneuvers help the arms and aftercoming head.
• Useful maneuvers/instruments: Bracht, Lovset/Muller for arms; Mauriceau-Smellie-Veit or Piper forceps for the aftercoming head.
• Total breech extraction is mainly for selected non-cephalic second twin, not routine singleton breech.

Complications

• Fetal/neonatal: cord prolapse or compression, head entrapment, birth asphyxia, intracranial hemorrhage, brachial plexus injury, fractures, perinatal death.
• Maternal: genital tract trauma, postpartum hemorrhage, operative delivery complications.