Core Concepts

Lie: Fetal long axis relative to mother’s.
- Longitudinal: Parallel (normal).
- Transverse: Perpendicular.
Presentation: Part entering the pelvic inlet.
- Cephalic (Vertex): Head first, chin tucked. Normal and most common.
Malpresentation: Any presentation other than vertex.
Position: Fetal presenting part relative to maternal pelvis.
- Occiput Anterior (OA): Ideal for delivery.
- Occiput Posterior (OP): “Sunny-side up”; associated with difficult, prolonged labor.

High-Yield Malpresentations

Breech Presentation
- What: Buttocks/feet first. Most common malpresentation (~3-4% at term).
- Risk Factors: Prematurity, multiple gestation, uterine anomalies (fibroids), polyhydramnios, placenta previa.
- Dx: Leopold maneuvers (head in fundus), confirmed with ultrasound.
- Management:
  - External Cephalic Version (ECV): Attempted at ≥37 wks to manually rotate fetus.
  - C-section: Indicated if ECV fails or is contraindicated.
Transverse Lie (Shoulder Presentation)
- What: Fetus is horizontal; shoulder presents.
- Complication: High risk of umbilical cord prolapse with rupture of membranes (ROM).
- Management: Vaginal delivery is impossible. Mandatory C-section.
Face & Brow Presentations
- What: Due to fetal head extension instead of flexion.
- Management:
  - Face: Vaginal delivery is possible only if chin is anterior (mento-anterior). If mento-posterior, C-section is required.
  - Brow: Largest presenting diameter. If persistent, C-section is required.