53. Placenta and the umbilical cord. Presentation and prolapse of the umbilical cord

Question 1

what is Umbilical cord prolapse?

Answer 1

an obstetric emergency
The cord slips ahead of the presenting part of the fetus and protrudes into the cervical canal or vagina, or beyond.

Question 2

why is umbilical cord prolapse an obstetric emergency?

Answer 2

because the prolapsed cord is vulnerable to compression, umbilical vein occlusion, and umbilical artery vasospasm, which can compromise fetal oxygenation

Question 3

in what two settings does Umbilical cord prolapse primarily occur?

Answer 3

1) when the presenting part does not adequately fill the pelvis because of maternal or fetal characteristics
2) when obstetric interventions (50%) are performed that dislodge the presenting part.

Question 4

Risk factors of Umbilical cord prolapse

Answer 4

malpresentation (breech, transverse, oblique, or unstable lie), prematurity, low birth weight, second twin, low lying placenta, pelvic deformities, uterine malformations/tumors, external fetal anomalies.

Question 5

what obstetric interventions allow umbilical cord prolapse?

Answer 5

iatrogenic rupture of membranes (especially with unengaged presenting part), cervical ripening with a balloon catheter, or induction of labor.

Question 6

what are the three types of umbilical cord prolapse?

Answer 6

1. overt umbilical cord prolapse (the most common type)
2. occult umbilical cord prolapse
3. Funic (cord) presentation

Question 7

what occurs in overt umbilical cord prolapse?

Answer 7

Descent of the umbilical cord past the presenting part; the cord advances through the cervix and into or beyond the vagina.
Requires rupture of membranes.

Question 8

what occurs in occult umbilical cord prolapse?

Answer 8

Descent of the umbilical cord alongside the presenting fetal part, but has not advanced past the presenting fetal part.
Can occur with both intact or ruptured membranes.

Question 9

what occurs in Funic (cord) presentation?

Answer 9

Presence of the umbilical cord between the presenting fetal part and fetal membranes. The cord has not passed the opening of the cervix.
The membranes are not yet ruptured.

Question 10

how does Umbilical cord prolapse usually present?

Answer 10

abrupt onset of severe, prolonged fetal bradycardia or moderate to severe variable decelerations in a patient with a previously normal tracing

Question 11

what is the optimal obstetric management for acute cord prolapse?

Answer 11

prompt delivery to avoid fetal compromise or death from compression of the cord between the presenting fetal part and the birth canal.

Question 12

what maneuvers are used to reduce the pressure on the cord while preparing for delivery?

Answer 12

1. manual elevation of the presenting part (most common)
2. Trendelenburg position (45° head-down position) or knee-chest position or Sims’ position
3. Retrofill the bladder
4. Administer a tocolytic

Question 13

how does retrofill of the bladder help in case of umbilical cord prolapse?

Answer 13

rapid filling of the bladder with 500-700 mL saline delivered through a catheter. Distends the bladder, which may gently elevate the presenting part of the fetus.

Question 14

how does tocolytics help in case of umbilical cord prolapse?

Answer 14

reduce the pressure on the cord from uterine contractions.