Obstetrics Simplified - Diaa
It is a cephalic presentation in which the head is midway between flexion
About 1:1000 labour.
As face presentation.
- During pregnancy:
- It is difficult.
- The occiput and sinciput may be felt at the same level.
- Ultrasonography and X-ray may be helpful.
- During labour:
- In addition to the previous findings, vaginal examination reveals
the following features:
- frontal bones,
- supra-orbital ridges, and
- root of the nose but not the chin.
Mechanism of Labour
- Persistent brow:
- The engagement diameter is the mento-vertical 13.5 cm which
is longer than any diameter of the inlet so there is no mechanism
of labour and labour is obstructed.
- Transient brow:
- may occur during conversion of vertex into face presentation.
So if brow is flexed to become vertex or extended to become face
it may be delivered.
- Early in the first stage:
- Exclude contracted pelvis, if present do caesarean section.
- The case is considered as transient brow, observed carefully
and given a chance for spontaneous conversion into either face or
- The rest of management as other malpresentation.
- In the second stage:
- The case is considered as persistent brow so:
- Caesarean section is done if the foetus is living.
- Craniotomy if the foetus is dead.
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Edited by Aldo Campana,