CERVICAL INCOMPETENCE Flashcards
Define cervical incompetence
CI is defined as a painless dilation of cervix in the absence of uterine contractions resulting in second or early third trimester delivery
T/F: There is an inability to hold the weight of the pregnancy resulting in bulging of the amniotic membranes into the vaginal canal leading to rupture of the membranes and preterm labour/fetal loss
T
T/F: Usually occurs in the 2nd trimester
T
Dimensions of the ectocervix
3cm long
2.5cm wide
In pregnancy the normal cervical length measured from internal to external os is
4cm +/- 1cm
T/F: Risk factors can broadly be classified into congenital and acquired
T
Apart from the acquired and congenital risk factors, 2 other risk factors are – and –
- Recurrent 2nd trimester losses
- History of incompetent cervix in a previous pregnancy
5 congenital risk factors for cervical incomptence
- Congenitally short Cx
- congenital cervical hypoplasia or
aplasia - Mullerian duct abnormalities
- Deficiencies in Cervical collagen
& elastin - Connective tissue
disorders (Ehlers-Danlos
syndrome) - DES (diethylstilbestrol) exposure
2 acquired risk factors for cervical incompetence
- Cervical injury
-multiple D&C
-Cervical laceration at SVD
-Prolonged 2nd stage of
labour
-surgical trauma
-cone biopsy
-cervical cautery (to remove
growths or stop bleeding) - Uterine over distention (multiple gestation, Polyhydramnios)
Cervical incompetence affects –% of the obstetric population
1%
% of 2nd trimester miscarriages (16 - 24 wks) attributed to cervical incompetence
15 - 20%
T/F: sonographic manifestations of CI often occur prior to clinically detectable Cervical changes
T
5 clinical manifestations of cervical incompetence
The classic presentation of CI is:
Cx dilatation and effacement in the 2nd trimester with fetal membranes visible at or beyond the external os in the absence of contractions. Which maybe asymptomatic or associated with:
Vaginal fullness or pressure
Spotting or bleeding
An ↥ volume of watery, mucous or brown VD
Vague discomfort in the lower abdomen or back
T/F: In non-pregnant woman there are no tests which can be performed to predict CI in a future pregnancy
T
In pregnant women diagnosis may be based upon –, –, and – criteria
historical, clinical or sonographic
5 historical criteria for the diagnosis of cervical incompetence
- History of two or more 2nd
trimester or early 3rd trimester
pregnancy losses - History of losing each pregnancy
at an earlier gestational age - History of painless cervical
dilatation of up to 4-6 cm - Absence of clinical findings
consistent with placental
abruption - History of cervical trauma caused by
-Cone biopsy, LLETZ
-Intrapartum cervical
lacerations
-Excessive, forced cervical
dilatation during TOP
How many 2nd trimester miscarriages qualify for a historical diagnosis of cervical incompetence
2 or more
T/F: Early 3rd trimester losses is a historical criteria for CI
T
History of painless cervical dilation up to –cm is a historical criteria for the diagnosis of CI
4 - 6cm
3 causes of cervical trauma leading to a historical diagnosis of CI
- Cone biopsy, LLETZ
- Intrapartum cervical lacerations
- Excessive, forced cervical dilatation during TOP
T/F: A digital examination should always be performed to evaluate the Cervix in cases of CI
T
Which dilator is used in the clinical diagnosis of CI
Size 8 Hegar dilators
3 clinical criteria for the diagnosis of CI
A digital examination should always be performed to evaluate the Cervix in cases of CI, followed by TVS if the clinical examination is not diagnostic (subjective)
Clinical findings include → significant premature Cervical effacement and/or dilatation (> 2cm) specially with prolapse of fetal membranes into or completely through the endocervical canal (hourglassing)
Cervix admits size 8 Hegars dilator freely.
The most consistent image of the cervix is obtained by – performed at – wks
TVS
≥ 13wks
T/F: transfundal pressure is more effective than standing in eliciting cervical changes during USS
T
T/F: Serial Ultrasound assessment of cervical length in women between 24-28 wks has been correlated with pre-term delivery
T
Noninvasive stress techniques used in eliciting USS cervical changes are –, – and –
Transfundal pressure
Coughing
Standing
On TVS the normal shape of the endocervical canal on saggital view is
T shaped
The shape of the endocervical canal on initial effacement is
Y shape
After the Y shape of the endocervical canal, the subsequent shapes are – and –
V and U visualized on progressive endocervical change and cervical shortening
4 sonographic findings for CI
- Funneling
- Cervical length < 25mm
- Protrusion of membranes
- Presence of fetal parts in cervix or vagina
Pneumonics for funneling
Trust - T shape
Your - Y shape
Vaginal - V shape
Ultrasound - U shape
T/F: If a patient presents with significant cervical dilation (2 cm or more) she may have minimal symptoms. (ie. Pelvic pressure, minimal contractions)
T
T/F: When the cervix reaches 4 cm or more, active uterine contractions or rupture of membranes may occur
T
4 non surgical treatment of CI
- Bed rest
- Pelvic rest - limit coitus
- IM Hydroxyprogesterone
- Vaginal pessaries
Define cerclage
Surgical purse string type suture used to reinforce the cervix.
Timing for cerclage
13-16 weeks GA after fetal viability established on ultrasound
Indication for urgent/therapeutic cerclage
urgent/therapeutic cerclage indicated for patients that have serial ultrasound changes consistent with short cervix or funneling.
T/F: Efficacy of cerclage is well proven
F
Cerclage- is the standard treatment for CI, despite little data from randomized trials proving efficacy
Size of mersilene tape used for the modified shirodkar cerclage procedure
5mm
Indication for the modified shirodkar procedure (1955)
Reserved for patients that have had failure with the Mcdonald procedure
At what level of the cervix is the mersilene tape placed in the modified shirodkar procedure
At the level of the internal os
Describe the modified shirodkar procedure
Performed using a 5 mm Mersilene tape placed around the Cervix at the level of the internal os after surgically reflecting the urinary bladder anteriorly & the rectum posteriorly
Describe the McDonald cerclage procedure (1963)
Purse-string suture placed around the cervix as cephalad as possible & without dissection of the bladder or rectum
Its tightened to reduce the cervical canal to 5-10mm
T/F: The mersilene tape is placed at the level of the internal os for the McDonald procedure
F. Purse-string suture placed around the cervix as cephalad as possible
T/F: Which of the cerclage procedures (shirodkar/Mcdonald) does not require dissection of the bladder or rectum
McDonald
T/F: In the McDonald procedure the cervical canal is sutured close
F.
Its tightened to reduce the cervical canal to 5-10mm
The transabdominal cerclage was developed by – and – in what year
Benson and Durfee in 1965
Timing for transabdominal cerclage
Post conception or preconception
Incision for transabdominal cerclage
Midline or pfannenstiel
Level of the stitch in transabdominal cerclage
Cervico-isthmic level via avascular window in the broad ligament
T/F: Delivery following transabdominal cercalge is always via CS
T
2 indications for transabdominal cerclage
Reserved for women with extremely short cervix and women with previously failed vaginal cerclage
T/F: The transabdominal cerclage can be done laparoscopically
T
T/F: Lash believed that there is a structural defect in the anterior cervix at the time of spontaneous abortion
T
When is the Lash procedure performed
In the nonpregnant state
T/F: The Lash procedure is permanent and the delivery is via CS
T
Success rate as described by Lash and Lash
86%
Describe the Lash procedure
Wedged-shaped segment of the area of defect in the anterior cervix is removed above the internal os and the remaining area is sutured with chromic catgut in two layers
List the surgical techniques for the management of CI
Modified Shirodkar cerclage (1955)
McDonald cerclage(1963)
Transabdominal cerclage
Lash procedure
T/F: no significant difference in prevention of PTB was observed using Shirodkar or McDonald’s procedures
T
Odibo et al (2007)
T/F: Blood loss is more with the McDonald technique compared the Shirodkar procedure
F.
More with Shirodkar
T/F: The McDonald type of cerclage is more widely used because the application is easier to perform
T
Chen (2017) and Berghella (2002)
T/F: Rodriguez et al (2018) found Shirodkar cerclage is associated with improved pregnancy prolongation, lower PTB rates, and better neonatal outcomes compared with McDonald cerclage.
T
T/F: Hessami (2021) in a systematic review and meta-analysis of pregnancy outcomes following McDonald versus Shirodkar cervical cerclage for prevention of preterm labour concluded that McDonald cerclage is associated with a shorter duration of pregnancy, lower mean birth weight and increased risk of PPROM and NICU admission compared to the Shirodkar procedure. But no significant difference was observed between both groups in terms of cesarean delivery and perinatal/neonatal death.
T
The surgical procedure accepted today as the standard of care is
The McDonald procedure
5 issues noted with the McDonald procedure
- Poor depth due to the Size of
the Mersilene Tape Needle
(65mm) - Slipping of the stitch [the
cerclage fell out spontaneously] - Compression of the Uterine
artery as the stitch wraps over
the artery at 3 and 9 o’clock
positions. - Laceration of the Cervix due to
multiple bites - Difficulty with application in
short and small size cervix
The Ikechebelu method is also known as –
Triangular 3 bites technique
Describe the triangular 3 bites technique (Ikechebelu method)
Sutures are placed at the 4, 8 and knotted at the 12 0’clock positions avoiding the branches of the uterine arteries at the 3 and 9 0’clock positions.
When is the cerclage removed electively
At 37 - 38 weeks
When should the cerclage be removed as an emergency
Immediately with the onset of premature labour to avoid cervical laceration and/or uterine rupture
T/F: Cerclage must be removed with PPROM
F
Controversial
What types of cerclage should not be removed
A Shirodkar or abdominal cerclage does not have to be removed as cesarean delivery is anticipated and if future pregnancies are planned
5 maternal contraindications to cerclage
- Premature labour
- Premature rupture of
membranes - Continuing vaginal bleeding
- Intra-amniotic, cervical, or
vaginal infection - Medical condition that precludes
administration of anesthesia or
continuation of pregnancy
4 fetal contraindications to cerclage
- Fetal demise
- Fetal anomaly incompatible with
extra-uterine life - Non-reassuring fetal status
- GA > 24 to 28 wks
5 intraoperative complications of cerclage
Rupture of membranes
Suture displacement
Chorioamnionitis
Haemorrhage
Trauma to surrounding organs – urinary bladder, urethra
3 postoperative complications of cerclage
Increased risk of caesarean section
Preterm delivery
Chorioamnionitis
Cerclage is for which class of women
Cervical length <2.5cm or advanced cervical changes on physical examination before 24 weeks gestation in women with either
One or more pregnancy losses / births at 14-34 weeks
Other significant risk factors for CI
History-indicated cerclage is recommended for which class of women
For women with two or more consecutive 2nd trimester pregnancy losses or three or more early preterm births who have risk factors for CI and in whom other causes of preterm births have been excluded — we recommend history indicated Cervical Cerclage
