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
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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
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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
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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
