Obstetrics Simplified - Diaa M. EI-Mowafi
Cord Presentation and Prolapse
Definitions
In both conditions a loop of the cord is below the presenting part. The difference is in the condition of the membranes; if intact it is cord presentation and if ruptured it is cord prolapse.
Incidence: 1:200.
The Risk
As long as the membranes are intact there is no risk. In cord prolapse, the foetal perinatal mortality is 25-50% from asphyxia due to:
- mechanical compression of the cord between the presenting part and bony pelvis and
- spasm of the cord vessels when exposed to cold or manipulations.
The prognosis is worse when the cord is more liable for compression as in:
- Primigravida than multipara.
- Cephalic than breech presentation or transverse lie.
- Partially than fully dilated cervix.
- Generally contracted than flat pelvis.
- Anterior than posterior position of the cord.
Aetiology
The presenting part is not fitting in the lower uterine segment due to:
- Foetal causes:
- Malpresentations: e.g. complete or footling breech, transverse and oblique lie.
- Prematurity.
- Anencephaly.
- Polyhydramnios.
- Multiple pregnancy.
- Maternal causes:
- Contracted pelvis.
- Pelvic tumours.
Predisposing factors:
- Placenta praevia.
- Long cord.
- Sudden rupture of membranes in polyhydramnios.
Diagnosis
- It is diagnosed by vaginal examination . If the cord is prolapsed it is necessary to detect whether it is pulsating i.e. living foetus or not i.e. dead foetus but this should be documented by auscultating the FHS.
- Ultrasound: occasionally can diagnose cord presentation.
Management
Cord presentation
Caesarean section: for contracted pelvis.
In other conditions the treatment depends upon the degree of cervical dilatation:
- Partially dilated cervix: prevent rupture of membranes as long as possible by:
- putting the patient in Trendelenburg position,
- avoiding high enema,
- avoiding repeated vaginal examination.
- When the cervix is fully dilated manage as mentioned later .
- Fully dilated cervix: the foetus should be delivered immediately by:
- Rupture of the membranes and forceps delivery: in engaged vertex presentation.
- Rupture of the membranes and breech extraction: in breech presentation.
- Rupture of the membranes + internal podalic version + breech extraction: may be tried in transverse lie otherwise,
- Caesarean section: is indicated as well as for non-engaged vertex and other cephalic malpresentations.
Cord prolapse
Management depends upon the foetal state:
- Living foetus:
- Partially dilated cervix: Immediate caesarean section is indicated. During preparing the theatre minimise the risk to the foetus by:
- putting the patient in Trendelenburg position,
- manual displacement of the presenting part higher up,
- if the cord protrudes from the vulva, handle it gently and wrap it in a warm moist pack.
- giving oxygen to the mother.
- Fully dilated cervix: the foetus should be delivered immediately as in cord presentation.
- Partially dilated cervix: Immediate caesarean section is indicated. During preparing the theatre minimise the risk to the foetus by:
- Dead foetus:
- Spontaneous delivery is allowed.
- Caesarean section: is the safest procedure in obstructed labour as destructive operations are out of modern obstetrics.
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