Malpresentation and Malposition

Malpresentation refers to any fetal presenting part other than vertex (cephalic with a well-flexed head), including breech, transverse or oblique lie, brow presentation, and face presentation.

Malposition refers to an abnormal position of a cephalic presenting part relative to the maternal pelvis, most commonly occipito-posterior (OP) position, where the fetal occiput points toward the maternal sacrum rather than the pubic symphysis.

• Transverse or oblique lie: fundal height and abdominal shape are atypical, with no presenting part palpable in the pelvis and the fetal poles palpable in the flanks
• Occipito-posterior position: often associated with a longer, more painful labor with significant back pain ("back labor"), and a higher likelihood of instrumental delivery or cesarean
• Brow presentation (partial extension of the fetal head): generally incompatible with vaginal delivery of a term-sized fetus given the larger presenting diameter
• Face presentation (full extension of the fetal head): vaginal delivery may be possible if mento-anterior, but mento-posterior face presentation is generally undeliverable vaginally

Clinical examination (abdominal palpation, vaginal examination in labor assessing fontanelle position and orientation) supported by ultrasound, which is more reliable for confirming position, particularly OP position, than palpation alone.

• Transverse or persistent oblique lie at term: admission is generally advised from around 37 to 38 weeks given the risk of cord prolapse with spontaneous rupture of membranes; stabilizing induction (attempting to correct the lie under controlled conditions with immediate access to cesarean) may be considered, but persistent unstable lie or transverse lie in labor requires cesarean section
• Occipito-posterior position: many rotate spontaneously to occipito-anterior during labor; persistent OP position causing delay may be managed with maternal positioning (hands and knees, forward-leaning positions), oxytocin augmentation if contractions are inadequate, or instrumental delivery (rotational forceps or ventouse) or cesarean if vaginal delivery is not achieved
• Brow presentation: generally requires cesarean unless it converts to either full flexion (vertex) or full extension (face) during labor
• Face presentation, mento-anterior: vaginal delivery may proceed with careful monitoring; mento-posterior face presentation generally requires cesarean, since further extension (which would be needed for descent) is not anatomically possible

Referral: obstetric-led care for any confirmed malpresentation or malposition in labor; senior obstetric review for any suspected transverse lie, brow, or face presentation.