Cervical insufficiency/cerclage

Pelvic Organ Prolapse

Placenta Praevia and Placenta Accreta

Published by Cleopas Banda at

Table of content

2. Risk Factors for Cervical Insufficiency

3. Diagnosis of cervical Incompetence

8. Information to be given to the patient before cerclage insertion

Cervical incompetence / insufficiency is an imprecise clinical diagnosis, defined as the inability of the cervix to retain a pregnancy in the absence of contractions or labour and is likely to represent a continuum, influenced by number of factors.

Risk factors

Past obstetric history: second trimester pregnancy losses/deliveries (especially in the setting of short labours or progressively earlier deliveries in successive pregnancies)
Congenital Collagen disease: Ehler-Danlos, Marfan syndrome, Uterine anomalies: septate uterus, fibroids, DES exposure: historical

Trauma -Cervical laceration (vaginal, instrumental or CS) , Mechanical dilatation , CIN treatment

Diagnosis of Cervical Incompetence:

There is insufficient evidence to recommend the use of pre pregnancy diagnostic techniques including:

Assessment of cervical resistance index
Hysterography
Insertion of cervical dilators

High risk groups:

Women with history of one or more spontaneous 2nd trimester loss or pre term delivery

Cervical Length Assessment

Women with a history of spontaneous second-trimester loss or preterm delivery who have not undergone a history-indicated cerclage may be offered serial sonographic surveillance.

Cervical length assessment should not be offered for women with

Multiple pregnancies
Uterine anomalies
One Large loop excision of transformation zone
Multiple dilatation curettage and evacuation

Timing and frequency of cervical length assessment

Between 14 – 24 weeks gestation
2 weekly examinations

The presence of funnelling (protrusion of the amniotic membranes in the cervical canal) with a normal residual cervical length is usually related to contraction of the lower uterine segment and it is not an indication for cerclage (Owen et al 2001).

Decision to perform serial ultrasound for cervical monitoring should be taken in consultation with the supervising consultant.

Cervical length scans should not be performed at more than 24weeks gestation as intervention is unlikely to be beneficial beyond this gestational age.

Management

Management will depend upon the magnitude of the risk of cervical insufficiency.

Offer a choice of either prophylactic vaginal progesterone or prophylactic cervical cerclage to women:

-With a history of spontaneous preterm birth or mid‑trimester loss between 16+0 and 34+0 weeks of pregnancy and

-In whom a transvaginal ultrasound scan has been carried out between 16+0 and 24+0 weeks of pregnancy that reveals a cervical length of less than 25 mm.

-Discuss the benefits and risks of prophylactic progesterone and cervical cerclage with the woman and take her preferences into account.

Consider prophylactic cervical cerclage for women in whom a transvaginal ultrasound scan has been carried out between 16+0 and 24+0 weeks of pregnancy that reveals a cervical length of less than 25 mm and who have either:

Had preterm pre-labour rupture of membranes (P-PROM) in a previous pregnancy or
A history of cervical trauma

Vaginal Progesterone can be given 200mg daily at night from 22 to 34 weeks

History indicated cerclage

It should be offered to women with three or more previous preterm births and / or 2nd trimester loss. It is performed as a prophylactic measure in an asymptomatic woman and should be inserted electively after 14wks

Ultrasound indicated cerclage

Insertion of a cerclage as a therapeutic measure in case of cervical length shortening seen on transvaginal scan.
US Surveillance: is indicated in a woman with a history of spontaneous mid trimester loss or pre term birth who has not undergone a history indicated cerclage.
Transvaginal sonographic surveillance of cervical length may be offered to these women between 14 and 24wks of gestation and if cervical length is < or = 25mm, cerclage is offered

Expectant management

This can be considered in women with history of 2nd trimester loss / preterm delivery rather than ultrasound surveillance and cerclage if indicated

Rescue cerclage

Insertion of cerclage as a salvage measure in the case premature cervical dilation with exposure of fetal membranes in the vagina.

Types of cerclage

Transvaginal (McDonald):

A transvaginal purse string suture placed at the cervicovaginal junction without bladder mobilization. Purse string stitch is inserted around the body of the cervix present in the vagina in three or four bites and so approximation to the internal os is less satisfactory, but the procedure is easier to perform with less bleeding. Merselene tape is used for the procedure. The knot is tied either anteriorly or posteriorly.

High Transvaginal Cerclage (Shirodkar):

A transvaginal purse string suture placed following bladder mobilization to allow insertion above the level of cardinal ligament.

Transabdominal Cerclage:

This suture can be performed via laparotomy or laparoscopy, the aim is to place suture at cervico-isthmic junction.
It is inserted when previous transvaginal cerclage has failed and can be associated with increase maternal morbidity. It can be performed preconceptually or in early pregnancy.
Management of delayed miscarriage/fetal death with abdominal cerclage is difficult and needs senior input.

Occlusion cerclage:

The occlusion of the external os by placement of continuous non-absorbable suture is known as occlusion cerclage. It should be individualized as data is limited.

Special Groups

Multiple Pregnancy-History or ultrasound indicated cerclage is not routinely recommended, will increase risk of pre term delivery and can be associated with an increase in preterm delivery and pregnancy loss.

Uterine Anomalies and Cervical Trauma-History or ultrasound indicated cerclage cannot be recommended in women with mullerian anomalies, previous cervical surgeries (cone biopsy, LLETZ or destructive procedures such as laser ablation or diathermy) or multiple dilatation and evacuation.
Radical Trachylectomy-Decision to place concomitant cerclage at radical trachylectomy should be individualized after discussion with Consultant

Contraindications

Active preterm labour
Clinical evidence of chorioamnionitis
Continuing vaginal bleeding
Preterm Premature Rupture of Membranes
Evidence of fetal compromise
Lethal fetal defects
Fetal death

Patient information

Risk of maternal pyrexia but no apparent chorioamnionitis
No Increased risk of PPROM, Induction of labour or Caesarean section
No increased risk of PID /2nd trimester loss
Small risk of intra operative bladder damage, cervical trauma, membrane rupture and bleeding during insertion
Shirodkar stitch requires anaesthesia for removal
Risk of cervical trauma / laceration if there is spontaneous labour with stitch in situ

Procedure

Pre-operative Management:

First trimester scan
Screening for aneuploidy
Anomaly scan (US indicated / rescue cerclage)
Routine White cell count and C-reactive protein is not indicated
No evidence to support genital tract screening before cerclage insertion but in the presence of positive cultures from genital swab, a complete course of sensitive antimicrobial eradication therapy before cerclage insertion is recommended

Operative management

Use of routine perioperative tocolysis is not recommended
Perioperative antibiotics can be considered
Type of anaesthesia is on anaesthetist discretion

Post-operative management

Can be done as a day case procedure
Consider 24 – 48 hrs stay in patients having US indicated or rescue cerclage
Cases should be managed on individual basis

Technique

Choice of suture material on surgeon’s discretion
Choice of transvaginal cerclage technique (Shirodkar / McDonald) should be at surgeon’s discretion
No role for two purse string sutures
No role of placement of cervical occlusion in addition to the primary cerclage

Adjuvant Management

Bed rest is not recommended routinely
Abstinence from intercourse should not be routinely recommended
Post cerclage sonographic surveillance for cervical length is not routinely recommended, it may be useful in individual cases following US indicated cerclage to offer timely steroids or in utero transfer
No role of repeat cerclage in presence of cervical length shortening
Decision to perform rescue cerclage following elective or US indicated cerclage should be made on individual basis , taking into account the clinical circumstances
Routine fetal fibronectin testing is not recommended
Routine use of progesterone supplement following cerclage is not recommended

Removal of cerclage

Should be removed after 37 weeks gestation, unless delivery is by Elective CS, in which case suture removal can be delayed till that time
If in established preterm labour, cerclage should be removed to minimise potential trauma to cervix
McDonald suture to be removed on the Delivery Suite
Shirodkar suture requires anaesthetic for removal
In case of abdominal cerclage, women will need delivery by CS and suture may be left in place following delivery
If PPROM occurs between 24-34 weeks of gestation without the evidence of infection or preterm labour, delayed removal for 48hrs can be considered to give time for steroids or in-utero transfer
Delayed removal until labour/ delivery is associated with an increased risk of maternal or fetal sepsis and is not recommended if gestation is <23wks or is >34wks, as it is unlikely to give benefits.

References

Preterm labour and birth. NICE guideline [NG25] Published date: November 2015
Cervical stitch (cerclage) for preventing preterm birth in singleton pregnancy. Alfirevic, Stampalija & Medley: Editorial Group: Cochrane Pregnancy and Childbirth Group. First published: 6 June 2017
Vaginal progesterone prophylaxis for preterm birth (the OPPTIMUM study): a multicentre, randomised, double-blind trial: Prof Jane Elizabeth Norman et al. OPPTIMUM study group. Lancet: Volume 387, No. 10033, p2106–2116, 21 May 2016
Effectiveness of progesterone, cerclage and pessary for preventing preterm birth in singleton pregnancies: a systematic review and network meta-analysis. Jarde et al: BJOG 2017; 124:1176–1189.