MALPRESENTATION &MALPOSITION

LECTURE OVERVIEW Abnormal lie, malpresentation and malposition Malpresentation and its management breech face brow shoulder compound

DEFINITIONS Abnormal lie where the long axis of the fetus is not lying along the long axis of the mother LONGITUDINAL (MAY BE EITHER CEPHALIC OR BREECH) TRANSVERSE OBLIQUE UNSTABLE

DEFINITIONS Malpresentation where the fetus is lying longitudinally, but presents in any manner other than vertex BREECH FACE BROW SHOULDER COMPOUND CORD

DEFINITIONS Malposition where the fetus is lying longitudinally and the vertex is presenting, but it is not in the OA position OT (LOT, ROT) OP

DEFINITIONS Malpresentation where the fetus is lying longitudinally, but presents in any manner other than vertex BREECH FACE BROW SHOULDER COMPOUND CORD

MANAGEMENT OF BREECH PRESENTATION AT TERM Management options (1) external cephalic version (2) elective caesarean section (3) trial of vaginal delivery

EXTERNAL CEPHALIC VERSION CONTRAINDICTAIONS: 3rd trimester bleeding uterine anomalies ROM, oligohydramnios need for CS for other reasons (placenta praevia, contracted pelvis, hyperextended head) indicated vaginal delivery (fetal death, anomaly best delivered as breech)

EXTERNAL CEPHALIC VERSION SUCCESS 60-70% TECHNIQUE after 36W CTG prior attempt to perform forward somersault tocolytic CTG after (8% bradycardia; 5% fetomaternal haemorrhage) anti D (if Rh negative)

ELECTIVE CAESAREAN SECTION EFW <2500g; >3500g preterm breech hyperextended fetal head palcenta praevia concerns re. fetal well being, including oligohydramnios footling breech 10% risk of cord prolapse ?complete breech 5% risk of cord prolapse (c.f. 1% with frank breech) ?all PG breech

CRITERIA FOR VAGINAL DELIVERY Frank or complete breech EFW 2500-3500g gestational age >36 weeks fetal head must be flexed maternal pelvis must be adequate judged clinically or by pelvimetry no other maternal or fetal indiaction for CS experienced obstetrician, anaesthetist and paediatrician present at delivery

FACE PRESENTATION Incidence: 0.2% Mechanics of presentation: Characterized by extreme extension of the fetal head so the face (rather than the skull) presents to the birth canal Aetiology any factor that favours extension such as fetal goitre, anencephaly high maternal parity At diagnosis: 60% mentoanterior 15% mentotransverse 25% mentoposterior

BROW PRESENTATION Incidence: 1:1400 Mechanics of presentation: head is extended such that attitude is halfway between flexion (vertex) and hyperextension (face) usually transitional- when the head is in the process of converting from a vertex to a face or vice versa presenting part is between the facial orbits and anterior fontanelle supraoccipitomental diameter is presenting 13.5cm; cf 9.5cm for suboccipitobregmatic (vertex) or submentobregmatic (face)

AETIOLOGY prematurity, multiple polyhydramnios anomaly praevia Fetal prematurity, multiple Liquor polyhydramnios Uterine anomaly Placenta praevia Pelvis contraction, tumour Parity high maternal parity (80% of cases occur in women who are para3 or more)

MANGEMENT occurs in up to 20% of cases Exclude cord prolapse occurs in up to 20% of cases Otherwise expectant mostly doesn’t interfere with normal delivery vertex-foot: try to gently reposition the lower extremity if arm prolapses in vertex-hand, wait and see if it moves as head descends; if it converts to shoulder presentation, deliver by CS

SUMMARY Abnormal lie, malpresentation, malposition Incidence, mechanics, aetiology, diagnosis, management of BREECH PRESENTATION FACE PRESENTATION BROW PRESENTATION SHOULDER PRESENTATION COMPOUND PRESENTATION