Malpresentations and Malpositions Flashcards
A malposition when the vertex is presenting is any position that is not what?
Occipito anterior (OA).
What is a malpresentation?
Any presentation that is not vertex.
Give three examples of malpresentation.
Breech, face, brow.
What is a compound presentation?
Two or more body parts presenting together.
Occipito posterior and occipito lateral positions are more common amongst which women?
Nulliparous women.
In the normal mechanism of labour, what causes descent and flexion?
Contractions and fetal axis pressure.
In the normal mechanism of labour, how much does the head internally rotate?
1/8th circle.
What is the term used to describe the occiput slipping under the pubic arch?
Crowning.
How is the head born in the normal mechanism of labour?
By extension.
How is the body born in the normal mechanism of labour?
By lateral flexion.
What two lifestyle factors increase the likelihood of having a malpresentation/position?
Living a sedentary lifestyle and having poor posture.
Which form of analgesia increases the incidence of malpresentations/positions?
Epidural analgesia.
For an occipito posterior fetus, what might you expect to feel on vaginal examination?
You might feel the bregmatic fontanelle and sagittal suture in the antero-posterior diameter.
What sensations do women with babies in malpositions report experiencing during labour?
Continuous and severe back pain. Rectal pressure. A strong desire to push prematurely.
Why is there an increased risk of ascending infection with malpresentations / malpositions?
Because there is often early rupture of membranes.
Give five potential complications of a malpresentation or malposition.
Any five of the following:
Prolonged labour
Cord prolapse
Early rupture of membranes (increased risk of ascending infection)
Urinary retention
Increased risk of instrumental/operative delivery
Increased risk of trauma to vagina and pelvic floor (associated with increased EBL)
Increased perinatal mortality and morbidity.
What position might you advise a woman to adopt if she is reporting a premature urge to push?
You might advise her to get on all fours, with her hips elevated and her face low to the mattress or mat.
Outcomes in labour for a malpresentation or malposition depend on what two factors?
The degree of descent and flexion, and the strength of contractions.
What five outcomes are there for an occipito posterior fetus in labour?
- Long internal rotation (delivery as OA).
- Deep transverse arrest.
- Short internal rotation (‘face to pubes’)
- Partial extension of head to brow presentation.
- Full extension of head to a mentoposterior face presentation.
What might management of a deep transverse arrest potentially include?
Kielland’s forceps, manual rotation or ventouse.
What determines whether the fetus will do a long internal rotation or short internal rotation?
The degree of flexion of the head: if the head remains deflexed, the sinciput reaches the pelvic floor first (will do a short internal rotation). If the head is flexed, the occiput reaches the pelvic floor first (will do a long internal rotation).
Why might you expect to see gaping of the vagina and anus if the fetus does a short internal rotation?
Because the large occiput lies in the hollow sacrum, applying pressure.
What might you expect to feel on vaginal examination if the fetus is in a persistent OP position?
The bregmatic fontanelle might be felt directly behind the symphysis pubis.
If extension is complete, what presentation results?
Face presentation.
If extension is incomplete, what presentation results?
Brow presentation.
