Malpresentations Flashcards
Fetal lie
Orientation of fetal spine relative to spine of mother (longitudinal, oblique, transverse)
Presentation
Presenting part which is the first portion of fetus to enter into pelvic inlet (cephalic, breech, shoulder)
Position
Presenting parts in relation to mom’s pelvis.
Determined by dividing mom’s pelvis into quadrants (anterior-posterior-transverse / right-left) , and determining reference point for fetal presenting part:
Cephalic – occiput (O), brow/fronto (F), face/chin (M)
Breech/sacrum/coccyx (S)
Shoulder– scapula (Sc), acromion (A)
Each presenting part has 6 possible positions. Right vs Left, O/F/M/S/Sc/A, and Anterior vs Posterior vs Transverse.
For occiput - LOA, LOP, LOT, ROA, ROP, ROT
Attitude
Position of fetal head in relation to neck (full flexion = normal, chin against upper chest). Various degrees of deflection or even extension which can lead to face or brow presentation.
a. complete flexion (normal)
b. moderate flexion (military)
c. poor flexion/marked extension
d. hyperextension (face)
Station
Depth of that the presenting part has descended into the pelvis in relation to ischial spines of mother’s pelvis.
Degree of advancement is measured in cm.
0 station = ischial spines
Above ischial spines = -1 to -5 (-1 lowest, -5 highest above pelvis)
Below ischial spines = +1 to +5 (+5 lowest descent of presenting part)
Variety
Relationship of the presenting part to the anterior, posterior, or transverse portion of the pelvis (part of flexion)
Malpresentation
- Not cephalic presentation (breech or shoulder)
Breech presentations
- Complete breech (feet tucked position, flexed at hips and one/both knees flexed)
- Footling/Incomplete breech (one or both feet or knees lie below the breech)
- Frank breech (pike position, hips flexed knees extended, feet toward head)
Characteristics of transverse/Oblique lies
Fetal spine or long axis crosses mothers’, may cause arm, foot or shoulder as presenting part. Shoulder is typically over pelvic inlet
Characteristics of shoulder presentation
Presentation is further based on which maternal side the fetal acromion rests, as well as by position of fetal back (i.e. dorsoanterior or dorsoposterior).
*at risk for cord prolapse
Characteristics of fundic presentation
Cord presentation
Umbilical cord is presenting part before fetus (bad news bears). Often happens with transverse /oblique lie
Characteristics of compound presentation
Extremity is prolapsed between main presenting fetal part (ie. hand over head) and both parts present simultaneously
Characteristics of face and brow presentation
Often presents with various degrees of fetal neck/chin deflection and extension (“attitude”).
Face presentation: longitudinal lie w/ full extension of fetal neck and head, and occiput against back.
Brow presentation: longitudinal lie with partially deflexed cephalic attitude midway between full flexion and full extension.
Landmarks of malpresentation/malpositions detectable by leopolds
- Face presentation: fetal cephalic prominence found on same side as maternal abdomen as fetal back with leopolds. More often discovered by vaginal exam
- Brow presentation: detection by leopolds unusual, more likely detected on vag exam during labor (different from face presentation b/c chin and mouth cannot be palpated on vag exam)
- Compound presentation: On vag exam, discovery of irregular mobile tissue mass adjacent to larger presenting part
- Shoulder presentation: weird feeling on leopolds, on vag exam feels bony, like small knob (vs round, smooth head)
- Funic presentation: feel pulsation on vag exam
- Breech presentation: dx may be made by leopolds or vag exam and c/w US
Risk factors for malpresentation & malpositions
Maternal:
- contracted pelvis
- high parity
- abnormal placentation, placentation high in fundus or low in pelvis
- uterine anomalies
- prior c/s
- sedentary lifestyle
- prior malposition/presentation (if d/t recurrent factor)
- obstructed pelvic outlet
- uterine fibroids
- cephalopelvic disproportion (associated with contracted maternal pelvis and severe fetal hydrocephalus)
Fetal:
- prematurity
- macrosomia
- fetal malformations
- multiples
- polyhydramnios
Potential complications of ALL malpresentation and malpositions
- fistulae
- lacerations
Face presentation complications
- 10x increase in fetal compromise
- Prolonged labor
- Associated with increased number of intrapartum death
- Fetal laryngeal and tracheal edema
Contraindications for vaginal delivery w/ face presentation:
- macrosomia
- NRFHT
- inadequate maternal pelvis
Brow presentation complications
- prolonged labor, secondary arrest
- C/S recommended if found ?
- Contraindicated – forced conversion of brow to more favorable position with forceps and attempts at manual conversion
Transverse lie/shoulder presentation complications
- cord prolapse
- arm prolapse in labor
- shoulder entrapment
- uterine rupture
- C/S delivery with persistent transverse lie
Compound presentation complications
- elevated perinatal mortality
- C/S
- birth trauma
- cord prolapse
- labor dystocia
- neuro/musculoskeletal damage to involved extremity
- labor dystocia
- C/S delivery
- maternal soft tissue damage
Funic presentation complications
- cord compression
- NRFHT
- stillbirth
- operative delivery
Breech presentation complications
- asphyxia and neuro damage from head entrapment, especially in PTB (head is bigger than abdomen and gets stuck)
- premature or aggressive intervention may adversely affect delivery d/t cervical retraction or deflexion of fetal neck –> larger occipitofrontal fetal cranial profile to pelvic inlet. Could be catastrophic and increase risk of nuchal arm
Vertex postural management (baby is vertex, but not occiput anterior)
-spinning babies exercise, walking, keeping knees below hips/leaning forward when sitting, keeping pelvis in neutral/engaged position.
Face, brow & compound presentation prevention
manage expectantly
- 50% of brows will convert to face or occiput by extending or flexing
- w/ compound, prolapsed part often retracts as labor progresses
transverse/should prevention
If dx before onset of labor, ECV recommended at 36-37 wks.
If still transverse, C/S
Preterm malpresentation delivery mode
C/S (usually classical)
Malposition
- Cephalic presentation with change in extension of fetal neck (median vertex/military, brow, face)
- Abnormal lie
- Flexed attitude
*often associated w/ increased risk to mother and fetus
