Malpresentation And Malposition

Question 1

What is the definition of a face presentation?

Answer 1

The fetal face from forehead to chin is the leading fetal body part descending into the birth canal.
The fetal neck is highly extended (sharply deflexed)

Question 2

What is the definition of a brow presentation?

Answer 2

The fetal surface presenting in the birth canal extends from the anterior fontanelle to the brow (orbital ridge), but does not include the mouth and chin. The fetal neck is extended, but to the degree of a face presentation

Question 3

What is the incidence of face presentation?

Answer 3

1:600-800

UTD

Question 4

What is the incidence of brow presentation?

Answer 4

1:500-4000

UTD

Question 5

What are risk factors for face and brow presentation?

Answer 5

Fetal

• anencephaly
• severe hydrocephalus
• anterior neck mass
• multiple unchallenged cords
• PTB and LBW
• LGA
• Polyhydramnios

Maternal

• contracted maternal pelvis
• CPD
• multiparty
• previous CS

Question 6

What is the management of a face presentation in labour

Answer 6

CEFM (not with FSE though!)
If mentum anterior, oxytocin and CS for standard obstetric indications
If mentrum posterior, will NOT delivery vaginally, so if persistent, for CS

Have equipment ready for airway support due to facial oedema from labour

Question 7

What is the management of brow presentation in labour?

Answer 7

CEFM
If clinically adequate pelvis and progressing normally, continue as approx 70% will spontaneously convert to a more favourable position

If FTP, for CS
Oxytocin augmentation, version, instrumental delivery NOT recommended

Question 8

In what position does the suboccipito-bregmatic diameter present?

Answer 8

OA

Smallest diameter
Average 9.5cm

Bregma = anterior fontanelle / sinciput

Question 9

In what position does the suboccipito-frontal diameter present?

Answer 9

OP

10cm

Question 10

In what position does the occipito-frontal diameter present?

Answer 10

OP, deflexed

14cm
Largest diameter