Breech Presentation - Clinical Features

Definition

Types of Breech Presentation

Incidence by Gestational Age

• 24% at 18-22 weeks
• 8% at 28-30 weeks
• 7% at 34 weeks
• 3% at 38-40 weeks (term)
• ~25-30% of all preterm infants (<28 weeks) are in breech position

Predisposing Factors / Etiology

• Prematurity (most common - the fetus has not yet rotated)
• Fundal-cornual placental implantation (occurs in 7% of pregnancies; restricts space for the head at the fundus, making breech position more "comfortable")
• Polyhydramnios (excessive fluid allows free fetal movement and instability)
• Oligohydramnios (limits movement, prevents version)
• Multiple pregnancy (twins, triplets - space constraint)
• Uterine abnormalities (fibroids, bicornuate uterus, septate uterus)
• Fetal abnormalities / neuromuscular disorders - fetuses with diminished muscle tone or motor deficits cannot rotate; neuromuscular conditions carry an inordinately high rate of breech presentation
• Prior breech presentation (recurrence risk)
• Multiparity (lax uterine walls)
• Contracted pelvis (CPD - prevents engagement of vertex)
• Placenta previa (occupies lower segment)
• Hydrocephalus (large head floats to fundus)

Clinical Features

1. Symptoms

• Often asymptomatic - the patient typically notices no difference
• May feel kicking or hard fetal parts in the lower abdomen
• Discomfort or pressure in the upper abdomen / under the ribs (head at fundus)

2. Abdominal Examination - Leopold's Maneuvers

• A hard, round, ballottable mass felt at the fundus - this is the fetal head
• The head is smooth, hard, and globular; moves independently of the trunk on ballottement (cephalic sulcus can be felt)

• Fetal back felt as a smooth, firm resistance on one side
• Small irregular parts (limbs) on the other side

• Soft, irregular, non-ballottable mass presenting at the lower pole / over the pelvic brim - this is the breech
• The breech is softer, less regular, and does NOT ballotte independently (unlike the head)

• Confirms the presenting part in the pelvis is soft / irregular (breech)
• The presenting part is not engaged or poorly engaged (breech engages later than vertex)

Note: In active labor, Leopold maneuvers may be difficult to perform reliably; vaginal examination is then required. - Rosen's Emergency Medicine

3. Auscultation

• Fetal heart sounds are heard above the umbilicus (in vertex they are below the umbilicus)
• Specifically heard at or above the umbilical level, toward the fetal back

4. Vaginal Examination

• Feel soft, irregular tissue (buttocks) instead of the hard, smooth head
• Anus and ischial tuberosities may be palpable; the anal orifice is flanked by bone on only two sides, whereas the face and skull have a complete circle of bone
• Meconium may stain the examining finger (from fetal gut compression)
• In frank breech: external genitalia may be felt
• In footling: feet may be felt (toes are distinguished from fingers by their alignment)
• In complete: both buttocks and feet/knees

5. Ultrasound (Confirmation)

• Bedside ultrasound is the definitive confirmatory tool
• Establishes type of breech, gestational age, fetal weight, amniotic fluid index
• Identifies hyperextended fetal neck (risk of spinal cord injury with vaginal delivery) and position of arms (nuchal arms increase dystocia)
• Rules out placenta previa and fetal anomalies

Associated Risks / Complications

• Cord prolapse - especially in footling breech (incomplete occlusion of cervical os)
• Head entrapment - after-coming head trapped by incompletely dilated cervix (particularly with preterm <1500 g)
• Fetal asphyxia - cord compression, entrapment
• Birth trauma - neck/arm injuries if delivery technique is incorrect; brachial plexus injury
• Hyperextended neck - associated with spinal cord injury if vaginal delivery attempted
• Developmental hip dysplasia - frank breech position (hips flexed, knees extended) increases risk

Key Differentiating Points on Vaginal Examination

Summary

1. Fundal head on Leopold maneuvers (hard, round, ballottable)
2. Soft presenting part in the lower pole / pelvis
3. Fetal heart sounds above the umbilicus
4. Vaginal examination - soft irregular presenting part without fontanelles
5. Ultrasound confirmation - mandatory before any management decision

• Creasy & Resnik's Maternal-Fetal Medicine: Principles and Practice
• Rosen's Emergency Medicine: Concepts and Clinical Practice
• Roberts and Hedges' Clinical Procedures in Emergency Medicine
• Tintinalli's Emergency Medicine: A Comprehensive Study Guide