UMBILICAL
CORD
PROLAPSE
Mariyam Riaz
WHAT IS THE UMBILICAL CORD?
• The umbilical cord is a flexible, tube-like structure that, during pregnancy,
connects the fetus to the mother.
• The umbilical cord is the baby's lifeline to the mother.
• It transports nutrients to the baby and also carries away the baby's waste
products.
• It is made up of three blood vessels – two arteries and one vein.
UMBILICAL CORD PROLAPSE
•
Umbilical cord prolapse occurs when the umbilical cord comes out of
the uterus with or before the presenting part of the fetus.
•
It is a relatively rare condition and occurs in fewer than 1% of pregnancies.
•
Cord prolapse is more common in women who have had rupture of
their amniotic sac.
•
Whenever there is a sudden decrease in fetal heart rate or abnormal fetal heart
tracing, umbilical cord prolapse should be considered.
•
Due to the possibility for fetal death and other complications, umbilical cord
prolapse is considered an obstetric emergency during pregnancy or labor.
CLASSIFICATION
There are three types of umbilical prolapse that can occur:
1.
Overt umbilical cord prolapse: descent of the umbilical cord past the presenting
fetal part. In this case, the cord is through the cervix and into or beyond the vagina.
Overt umbilical cord prolapse requires rupture of membranes. This is the most
common type of cord prolapse.
2.
Occult umbilical prolapse: descent of the umbilical cord alongside the presenting
fetal part, but has not advanced past the presenting fetal part. Occult umbilical
prolapse can occur with both intact or ruptured membranes.
3.
Funic (cord) presentation: presence of the umbilical cord between the presenting
fetal part and fetal membranes. In this case, the cord has not passed the opening of
the cervix. In funic presentation, the membranes are not yet ruptured.
EPIDEMIOLOGY
The incidence of umbilical cord prolapse ranges from 0.1-0.6% of all
pregnancies.
A recent study estimates 77% of cord prolapses occur in singleton
pregnancies, or those where there is only one fetus.
In twin pregnancies, cord prolapses occur more frequently in the second twin
to be delivered, with 9% in the first twin and 14% in the second twin.
PATHOGENESIS
The pathogenesis of umbilical cord prolapse is not always clear.
One probable mechanism is high outward flow of amniotic fluid at rupture of
membranes that carries the umbilical cord past an unengaged fetal presenting
part.
Another probable mechanism is disengagement of the presenting part during
obstetric procedures, allowing the cord to prolapse.
WHAT CAUSES AN UMBILICAL
CORD PROLAPSE?
The most common cause of an umbilical cord prolapse is a premature rupture of the
membranes that contain the amniotic fluid. Other causes include:
1.
Premature delivery of the baby
2.
Delivering more than one baby per pregnancy (twins, triplets, etc.)
3.
Excessive amniotic fluid
4.
Breech delivery (the baby comes through the birth canal feet first)
5.
An umbilical cord that is longer than usual
DIAGNOSIS
• Feeling the cord dropping into the vagina or your midwife seeing the cord
come out before the presenting part of the baby are the most obvious
ways to confirm a UCP.
• Pelvic examination
• Fetal heart rate on a fetal Doppler following the waters breaking (A
prolapse is suspected in case it suddenly drops below 120 beats a minute,
as it might indicate a lack of oxygen supply through the cord.)
• An ultrasound scan performed before delivery to check the cord
compression may also detect the problem.
MANAGEMENT
C-section, especially if the woman is in early labor.
Vaginal delivery, if clinical judgment determines that is a safer or quicker method.
The following maneuvers are among those used in clinical practice:
Manual elevation of the presenting fetal part
Repositioning of the mother to be head down with feet elevated
Filling of the bladder with a foley catheter, or tube through the urethra to elevate the presenting
fetal part.
Use of tocolytics (medications to suppress labor) have been proposed, usually in addition to
bladder filling rather than a standalone intervention.
If the mother is far from delivery, funic reduction (manually placing the cord back
into the uterine cavity) has been attempted, with successful cases reported.
RISK FACTORS
T h e two m a jo r ca tego ri es o f ri s k f a cto r s a r e s p o n ta neous
a nd i a tr ogeni c , o r th o s e th a t r es u lt fr o m m ed i ca l
i n ter venti on .
•
Spontaneous factors:
•
Fetal malpresentation: abnormal fetal lie tends to
result in space below the fetus in the maternal
pelvis, which can then be occupied by the cord.
Multiple gestation, or being pregnant with more
than one fetus at a given time: more likely to occur
in the fetus that is not born first.
•
Spontaneous rupture of membranes about half of
prolapses occur within 5 minutes of membrane
rupture, two-thirds within 1 hour, 95% within 24
hours.
•
Polyhydramnios, or an abnormally high amount of
amniotic fluid.
•
Prematurity: likely related to increased chance of
malpresentation and relative polyhydramnios.
•
Low birth weight: usually described as <2500 g at
birth, though some studies will use <1500g. Cause
is likely similar to those for prematurity.
Iatrogenic factors:
•
Artificial rupture of membranes
•
Placement of internal monitors (for
example, internal scalp electrode or intrauterine
pressure catheter
•
Manual rotation of fetal head