Malpresentations and Malpositions

Question 1

A malposition when the vertex is presenting is any position that is not what?

Answer 1

Occipito anterior (OA).

Question 2

What is a malpresentation?

Answer 2

Any presentation that is not vertex.

Question 3

Give three examples of malpresentation.

Answer 3

Breech, face, brow.

Question 4

What is a compound presentation?

Answer 4

Two or more body parts presenting together.

Question 5

Occipito posterior and occipito lateral positions are more common amongst which women?

Answer 5

Nulliparous women.

Question 6

In the normal mechanism of labour, what causes descent and flexion?

Answer 6

Contractions and fetal axis pressure.

Question 7

In the normal mechanism of labour, how much does the head internally rotate?

Answer 7

1/8th circle.

Question 8

What is the term used to describe the occiput slipping under the pubic arch?

Answer 8

Crowning.

Question 9

How is the head born in the normal mechanism of labour?

Answer 9

By extension.

Question 10

How is the body born in the normal mechanism of labour?

Answer 10

By lateral flexion.

Question 11

What two lifestyle factors increase the likelihood of having a malpresentation/position?

Answer 11

Living a sedentary lifestyle and having poor posture.

Question 12

Which form of analgesia increases the incidence of malpresentations/positions?

Answer 12

Epidural analgesia.

Question 13

For an occipito posterior fetus, what might you expect to feel on vaginal examination?

Answer 13

You might feel the bregmatic fontanelle and sagittal suture in the antero-posterior diameter.

Question 14

What sensations do women with babies in malpositions report experiencing during labour?

Answer 14

Continuous and severe back pain. Rectal pressure. A strong desire to push prematurely.

Question 15

Why is there an increased risk of ascending infection with malpresentations / malpositions?

Answer 15

Because there is often early rupture of membranes.

Question 16

Give five potential complications of a malpresentation or malposition.

Answer 16

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.

Question 17

What position might you advise a woman to adopt if she is reporting a premature urge to push?

Answer 17

You might advise her to get on all fours, with her hips elevated and her face low to the mattress or mat.

Question 18

Outcomes in labour for a malpresentation or malposition depend on what two factors?

Answer 18

The degree of descent and flexion, and the strength of contractions.

Question 19

What five outcomes are there for an occipito posterior fetus in labour?

Answer 19

1. Long internal rotation (delivery as OA).
2. Deep transverse arrest.
3. Short internal rotation (‘face to pubes’)
4. Partial extension of head to brow presentation.
5. Full extension of head to a mentoposterior face presentation.

Question 20

What might management of a deep transverse arrest potentially include?

Answer 20

Kielland’s forceps, manual rotation or ventouse.

Question 21

What determines whether the fetus will do a long internal rotation or short internal rotation?

Answer 21

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).

Question 22

Why might you expect to see gaping of the vagina and anus if the fetus does a short internal rotation?

Answer 22

Because the large occiput lies in the hollow sacrum, applying pressure.

Question 23

What might you expect to feel on vaginal examination if the fetus is in a persistent OP position?

Answer 23

The bregmatic fontanelle might be felt directly behind the symphysis pubis.

Question 24

If extension is complete, what presentation results?

Answer 24

Face presentation.

Question 25

If extension is incomplete, what presentation results?

Answer 25

Brow presentation.