28. Malpresentations

Question 1

what are malpresentations?

Answer 1

any fetal position other than cephalic vertex at delivery – any fetal part other than the head engaging the maternal pelvis.

Question 2

when does face presentation occur?

Answer 2

when the fetal head is hyperextended such that the fetal face (between the chin and orbits) is the presenting part.

Question 3

what factors cause face presentation?

Answer 3

extreme prematurity, ↑ maternal parity, and congenital anomalies (ex. goiter).

In most cases, a specific etiologic factor cannot be identified.

Question 4

what should be rules out in case of face presentation

Answer 4

anencephaly

Question 5

when is diagnosis of face presentation made?

Answer 5

at the time of vaginal examination during labor
can then be confirmed with US.

Question 6

how is face presentation classified?

Answer 6

according to the location of the fetal chin (mentum):
mentum anterior (65%)
mentum transverse (15%)
mentum posterior (25%).

Question 7

management for Mentum posterior cases and those with persistent mentum transverse

Answer 7

must be delivered by cesarean delivery

Question 8

management of mentum aneterior

Answer 8

vaginal delivery, assisted by simpson forceps

Question 9

when does brow presentation occur?

Answer 9

when the presenting part of the fetus is between the facial orbits and anterior fontanelle
Arises as a result of fetal head extension that is midway between flexion (vertex presentation) and hyperextension (face presentation).

Question 10

brow presentation can convert to?

Answer 10

50-75% to face (through extension)
vertex (through flexion)

Question 11

brow presentation must be delivered by cesarean delivery unless?

Answer 11

the fetus is very small or the maternal pelvis is very large

Question 12

when does compound presentation and shoulder presentation occur?

Answer 12

when a fetal extremity (usually the hand) prolapses alongside the presenting part (the head) and both parts enter the maternal pelvis at the same time

Question 13

Compound presentation and shoulder presentation occurs more frequently with?

Answer 13

premature gestations

Question 14

what should be done in case the complete extremity prolapses and the fetus then convert to a shoulder presentation?

Answer 14

cesarean delivery

Question 15

what is the approach in case the arm prolapses?

Answer 15

1. wait and see if it moves out of the way if the head descends
2. if it does not- the arm may be gently pushed upward while the head is simultaneously pushed downward by fundal pressure

**in cases were the prolapsed part doesn’t interfere with labor