Cervical Insufficiency

Obstetrics

Clinicals - History

Fact Explanation
Recurrent second or early third trimester fetal loss Painless cervical dilatation occurs first followed by prolapse and/ or rupture of the membranes and consequently fetus is expelled despite lack of uterine contraction. Recurrent second or early third trimester fetal loss
Painless cervical dilatation occurs first followed by prolapse and/ or rupture of the membranes and consequently fetus is expelled despite lack of uterine contraction.
Single event of second or early third trimester fetal loss In single event of such occurrence cervical insufficiency is suspected when other causes of preterm delivery is excluded. Single event of second or early third trimester fetal loss
In single event of such occurrence cervical insufficiency is suspected when other causes of preterm delivery is excluded.
Previous cervical surgery Amputation of the cervix, cervical conization, routine dilation of cervix for diagnostic or therapeutic reasons Previous cervical surgery
Amputation of the cervix, cervical conization, routine dilation of cervix for diagnostic or therapeutic reasons
Laceration/ trauma of cervix May have been caused by previous transvaginal encerclage or rupture of cervix Laceration/ trauma of cervix
May have been caused by previous transvaginal encerclage or rupture of cervix
Previously treated cervical cancer Cervical cancer result in structural damage to the cervix Previously treated cervical cancer
Cervical cancer result in structural damage to the cervix
Past history of preterm delivery As the chance of preterm delivery is inversely related to the length of cervical canal, This is a known risk factor for cervical insufficiency Past history of preterm delivery
As the chance of preterm delivery is inversely related to the length of cervical canal, This is a known risk factor for cervical insufficiency
Previous termination of pregnancy This is associated with increased cervical insufficiency in current pregnancy and as number of previous termination increases the prevelance increases. This maybe associated with shortening of cervix caused by repeated termination. Previous termination of pregnancy
This is associated with increased cervical insufficiency in current pregnancy and as number of previous termination increases the prevelance increases. This maybe associated with shortening of cervix caused by repeated termination.
History of renal disease, diabetes, hydramnios and anemia High prevalence of cervical insufficiency is seen with these conditions. And a theory regarding the role of non enzymatic glycation of cervical collagen in cervical insufficiency has been postulated, since post translational modification of protein by glycation is seen diabetes/ diabetic renal disease. History of renal disease, diabetes, hydramnios and anemia
High prevalence of cervical insufficiency is seen with these conditions. And a theory regarding the role of non enzymatic glycation of cervical collagen in cervical insufficiency has been postulated, since post translational modification of protein by glycation is seen diabetes/ diabetic renal disease.
Race of the pregnant woman Black pregnant woman has more than twice the chance of developing cervical insufficiency in comparison to a white pregnant woman. Race of the pregnant woman
Black pregnant woman has more than twice the chance of developing cervical insufficiency in comparison to a white pregnant woman.
Smoking This is a known risk factor for cervical insufficiency Smoking
This is a known risk factor for cervical insufficiency
Family history of cervical insufficiency About one forth of the women with cervical insufficiency have a first degree relative who also has cervical insufficiency. Family history of cervical insufficiency
About one forth of the women with cervical insufficiency have a first degree relative who also has cervical insufficiency.

Clinicals - Examination

Fact Explanation
The Diagnosis is retrospective or of exclusion Classic Cervical insufficiency is a retrospective diagnosis made following recurrent second or early third trimester loss.
In case of an single event it's a diagnosis of exclusion
The Diagnosis is retrospective or of exclusion
Classic Cervical insufficiency is a retrospective diagnosis made following recurrent second or early third trimester loss.
In case of an single event it's a diagnosis of exclusion
Speculum Examination Dilated cervix/,bulging membranes in second/ early third trimester maybe seen Speculum Examination
Dilated cervix/,bulging membranes in second/ early third trimester maybe seen

Investigations - Diagnosis

Fact Explanation
Cervical length measurement A short cervical length is associated with cervical insufficiency. Cervical length <30 mm as measured by transvaginal ultrasonography predicts preterm delivery with positive predictive value of 54% and negative predictive value of 95%.
Also serial measurements are used in patients with risk factors for cervical insufficiency and if shortening and dilatation occurs emergency cerclage is performed; but prophylactic cerclage is preferred over this method at an early stage.
Cervical length measurement
A short cervical length is associated with cervical insufficiency. Cervical length <30 mm as measured by transvaginal ultrasonography predicts preterm delivery with positive predictive value of 54% and negative predictive value of 95%.
Also serial measurements are used in patients with risk factors for cervical insufficiency and if shortening and dilatation occurs emergency cerclage is performed; but prophylactic cerclage is preferred over this method at an early stage.
Fetal fibronectin (fFN) levels in cervicovaginal secretions Elevated levels with increased cervical length can be used to predict preterm delivery. Fetal fibronectin (fFN) levels in cervicovaginal secretions
Elevated levels with increased cervical length can be used to predict preterm delivery.
Intrauterine cultures Positive cultures reveals intrauterine infections which trigger cytokine production, synthesis & release of prostaglandins which cause changes in cervix Intrauterine cultures
Positive cultures reveals intrauterine infections which trigger cytokine production, synthesis & release of prostaglandins which cause changes in cervix
Interleukin-6 levels in amniotic fluid Elevated levels indicate intrauterine inflammation and predicts possible preterm delivery of uterus Interleukin-6 levels in amniotic fluid
Elevated levels indicate intrauterine inflammation and predicts possible preterm delivery of uterus
Screening for vaginal organisms It has been proven that in women with previous preterm delivery, if bacterial vaginosis is diagnosed in second trimester, the chances of miscarriage or a preterm delivery is high Screening for vaginal organisms
It has been proven that in women with previous preterm delivery, if bacterial vaginosis is diagnosed in second trimester, the chances of miscarriage or a preterm delivery is high

Investigations - Management

Fact Explanation
Serial cervical length measurements This is not regularly carried out as once identified as at risk for cervical insufficiency, a prophylactic cerclage is more safer than serial ultrasonic assessment of cervical length Serial cervical length measurements
This is not regularly carried out as once identified as at risk for cervical insufficiency, a prophylactic cerclage is more safer than serial ultrasonic assessment of cervical length

Management - Supportive

Fact Explanation
Cessation of smoking Smoking is a known predisposing factor, thus cessation aids prevention of cervical insufficiency. Cessation of smoking
Smoking is a known predisposing factor, thus cessation aids prevention of cervical insufficiency.
Avoid cervical trauma To prevent cervical insufficiency cervical trauma should be avoided when possible. Usage of prostaglandin ( Eg: misoprostol) with antiprogesterone priming (Eg: mifepriston) is of value in cases of legal termination of pregnancy, this avoids excessive cervical trauma. Avoid cervical trauma
To prevent cervical insufficiency cervical trauma should be avoided when possible. Usage of prostaglandin ( Eg: misoprostol) with antiprogesterone priming (Eg: mifepriston) is of value in cases of legal termination of pregnancy, this avoids excessive cervical trauma.
Early identification and treatment of cervical malignancies This can be considered as a preventive method in a way to reduce cervical damage conferred by the malignant condition but the treatment methods for such are not entirely damage free Early identification and treatment of cervical malignancies
This can be considered as a preventive method in a way to reduce cervical damage conferred by the malignant condition but the treatment methods for such are not entirely damage free
Support groups/ counselling Bereavement after fetal loss would be equivalent to any death but typically lasts for lesser period, however support groups maybe of use; but there are no proven benefits from such psychological support/ councelling. Support groups/ counselling
Bereavement after fetal loss would be equivalent to any death but typically lasts for lesser period, however support groups maybe of use; but there are no proven benefits from such psychological support/ councelling.

Management - Specific

Fact Explanation
Prophylactic cervical cerclage Proven to be useful in medium and high risk patients and can be performed even prior to or after conception. This has not proven to be useful in patients with low risk.
The cerclage can be performed at 3 different sites.
1. Regular transvaginal cerclage- Cerclage put at the junction of cervix and fornix, the lowest level of all 3 methods. This method is performed easily with short hospital stay but has higher risk of infection as when funneling occurs (opening of the cervix at the internal os following increased intrauterine pressure), only a small length of cervix remains between the membrane and the bacteria in the vaginal canal below, thus the bacteria can easily get to the membrane. Also funneling exerts a dilating pressure on remaining cervix and the short length gives only a small mechanical support against this pressure.
2. High-transvaginal cerclage - Suture is put higher up in cervix than in regular transvaginal cerclage and performed after opening up the fornix. Thus has better protection from ascending infection and cervical dilatation than regular cerclage.
3. Transabdominal cerclage- The suture is put at the level of the internal cervical os, thus funneling is prevented, therefore best in terms of prevention of infection and dilatation but requires high surgical technique and longer hospital stay.

Different type of suturing techniques can be used too.
1. Modified Shirodkar - Cerclage is put by suturing right around the cervical circumference.
2. Modified McDonald - Performed by a series of small bites along the cervical circumference.
3. Four-steps cerclage - Four deep, large bites of cervix is taken during suture and is considered to have higher mechanical strength than other 2 techniques as the band passes deeper than them, thus the chance of cervical tear is low even with uterine contraction.
Prophylactic cervical cerclage
Proven to be useful in medium and high risk patients and can be performed even prior to or after conception. This has not proven to be useful in patients with low risk.
The cerclage can be performed at 3 different sites.
1. Regular transvaginal cerclage- Cerclage put at the junction of cervix and fornix, the lowest level of all 3 methods. This method is performed easily with short hospital stay but has higher risk of infection as when funneling occurs (opening of the cervix at the internal os following increased intrauterine pressure), only a small length of cervix remains between the membrane and the bacteria in the vaginal canal below, thus the bacteria can easily get to the membrane. Also funneling exerts a dilating pressure on remaining cervix and the short length gives only a small mechanical support against this pressure.
2. High-transvaginal cerclage - Suture is put higher up in cervix than in regular transvaginal cerclage and performed after opening up the fornix. Thus has better protection from ascending infection and cervical dilatation than regular cerclage.
3. Transabdominal cerclage- The suture is put at the level of the internal cervical os, thus funneling is prevented, therefore best in terms of prevention of infection and dilatation but requires high surgical technique and longer hospital stay.

Different type of suturing techniques can be used too.
1. Modified Shirodkar - Cerclage is put by suturing right around the cervical circumference.
2. Modified McDonald - Performed by a series of small bites along the cervical circumference.
3. Four-steps cerclage - Four deep, large bites of cervix is taken during suture and is considered to have higher mechanical strength than other 2 techniques as the band passes deeper than them, thus the chance of cervical tear is low even with uterine contraction.
Monitoring of cervical length followed by emergency/ urgent cerclage if impending cervical insufficiency occurs. Cervical length can be monitored serially by ultrasound scan and if cervical shortening and dilatation occurs an emergency cerclage can be performed if membranes are not bulging and and urgent cerclage if membranes are already bulging out. This when combined with tocolytics, antibiotics and bed rest have better outcome. However a prophylactic cerclage is considered safer than this method Monitoring of cervical length followed by emergency/ urgent cerclage if impending cervical insufficiency occurs.
Cervical length can be monitored serially by ultrasound scan and if cervical shortening and dilatation occurs an emergency cerclage can be performed if membranes are not bulging and and urgent cerclage if membranes are already bulging out. This when combined with tocolytics, antibiotics and bed rest have better outcome. However a prophylactic cerclage is considered safer than this method
Cerclage pessary This can be used instead of prophylactic cerclage but the efficacy of this has not been proven. Cerclage pessary
This can be used instead of prophylactic cerclage but the efficacy of this has not been proven.
Progesterone This prevents uterine contraction and the efficacy is not proved and some use this in conjunction with cervical cerclage Progesterone
This prevents uterine contraction and the efficacy is not proved and some use this in conjunction with cervical cerclage

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