15 cervical insufficiency imaging dr ahmed esawy Cervical Insufficiency (Cervical Incompetence) Cervix Measurement Image Criteria short cervix Funnelling Cervical Effacement cerclage

1. ‫الرحيم‬ ‫الرحمن‬ ‫هللا‬ ‫بسم‬

2. Dr. Ahmed Esawy
MBBS M.Sc
MD
Dr/AHMED ESAWY

3. Cervical Insufficiency
(Cervical Incompetence)
DR/AHMED ESAWY

4. ANATOMY OF THE CERVIX
• EMBRYLOGICALLY IT IS DERIVED FROM THE FUSION OF
THE MULLERIAN DUCTS AND SUBSEQUENT CENTRAL
ATROPHY
• THE CERVIX IS PRIMARILY FIBROUS TISSUE WITH SOME
MUSCLE
• THE PROXIMAL CERVIX MAY HAVE UP TO 29 % MUSCLE
AND THE DISTAL PORTION LESS THAN 10 %
DR/AHMED ESAWY

5. NON PREGNANT CERVICAL
EVALUATION
NON PREGNANT CERVICAL TEST ARE INACCURATE OR
UNPROVEN AND NOT RECOMMENDED
INTERNAL OS MEASUREMENT >8mm ON
HYSTEROSALPINGOGRAM
DR/AHMED ESAWY

6. Dfinition of Cervical Incompetence
• Gradual painless dilatation and effacement of
the cervix with bulging and later rupture of
the membranes
DR/AHMED ESAWY

7. SIGN AND SYMPTOM OF CERVICAL
INCOMPTENCE
• Vaginal or lower abdominal pressure
• Frequent urination
• Increased vaginal discharge (watery)
• Bloody or mucus discharge
DR/AHMED ESAWY

8. Causes of cervical incometent
Congenital
• Congenital Mullerian anomalies with the highest risk with
bicornuate and unicornuate utrei
• Abnormal uterine shape
• Also abnormal cervical muscular content
( Ehlers – Danlos syndrome )
Acquired incompetence
• Traumatic cervical procedures (cone bx)
• Cone bx’s with a height of > 2 cms is a risk factor
• Obstetrical cervical lacerations
• Iatrogenic
• Embryological Drug induced (DES) (about 25 % have structural defects)
DR/AHMED ESAWY

9. Ultrasound assessment of the cervix
• Trans abdominal scanning needs a full maternal
bladder and can therefore elongate the cx length .
can be very difficult to see the external os
• Transperineal cervical measurements (Gas of the
rectum will hamper visualization of the cx
especially the external os )
DR/AHMED ESAWY

10. Transvaginal technique
• Enlarge the image so that it occupies about
two thirds of the total image
• Obtain 3 images and record the shortest.
• Transfundal pressure should be for about 15
seconds
• Generally sonographers should be supervised
for about 50 procedures.
DR/AHMED ESAWY

11. Cervical scan technique
• Check the Equipment
– Appropriately cleaned w/ soap & water + soaked
– Use 5 to 7 MHz endovaginal probe
• Don’t use 8 MHz – poor tissue penetration
– Make sure the image is set to “EV” (endovaginal )
• Not Obstetrical or Abdominal
• Empty Maternal Bladder
– Void just before the exam
– If bladder is seen to be large, stop exam & void again
DR/AHMED ESAWY

12. Cervix Measurement Image Criteria
• Transvaginal Image
• Cervix Occupies 75% of the Image
• Anterior Width = Posterior Width
• Maternal Bladder Empty
• Internal Os Seen
• External Os Seen
• Cervix Canal Visible Throughout
• Caliper Placement Correct
• Cervix Mobility Considered
DR/AHMED ESAWY

13. • there is a strong reproducible inverse
correlation between cx length and preterm
delivery
• if the cx length is less than 10 % (25 mm)
there is a 6 fold increased risk of delivery prior
to 35 weeks
DR/AHMED ESAWY

14. • PROGRESSIVE CX SHORTENING TO 20 mm OR LESS
• FUNNEL LENGTH >16 mm OR FUNNELING >40 %
• MEASUREMENTS MUST BE OBTAINED
TRANSVAGINALLY
DR/AHMED ESAWY

15. Standard cervical measurements use the "white stripe"
of the internal cervical os as an anatomic landmark for
proper caliper placement
Anderson found an average length of
45 ± 7 mm at 14 to 30 weeks,
Iams et al found a mean cervical length of 35 ± 8
mm at 24 weeks'
Basic parameters
DR/AHMED ESAWY

16. Defining the short cervix
The discriminatory length of
cervical shortening varies
widely between 26mm (Iams et
al ) to 15mm (Hassan et al )
DR/AHMED ESAWY

17. So in the presence of progressive shortening
Look for other cervical qualities such as
1-funneling (and measurement of the residual
cervix if funneling is present),
2-v-shaped lower uterine segment
3-dynamic changes with fundal or suprapubic
pressure. Are the most important
4-residual cervical length is more important than
the other measurements
DR/AHMED ESAWY

18. • Funnelling specifically refers to the separation
of the internal os from the two sidewalls of the
upper end of the cervical canal.
• A normal sagittal view of the cervix shows a
“T” shaped endocervical canal vs. deviations
such as Y, V, U.
• Y= initial effacement and subsequent V, U
visualized on progressive endocervial change
and cervical shortening.
• Moderate funneling defined as 25- 50%
cervical shortening had a increased preterm
birth of 50 %
Transvaginal ultrasound
DR/AHMED ESAWY

19. DR/AHMED ESAWY

20. DR/AHMED ESAWY

21. Calipers
• Where the anterior
and posterior walls of
the canal touch
• Spend enough time to
see whether a small
echolucent area is
stable or is going to
open up
YES
NO
DR/AHMED ESAWY

22. Fetal
Head
Posterior
Cervical Lip
Bladder
Ext Os
Int Os
DR/AHMED ESAWY

23. 1 2
3
4
DR/AHMED ESAWY

24. Sonographic findings
-funneling
-cervical length <25mm
-protrusion of
membranes
-presence of fetal parts
in cervix or vagina
DR/AHMED ESAWY

25. DR/AHMED ESAWY

26. Transvaginal Cervical Sonography
DR/AHMED ESAWY

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31. Cervical Effacement = T Y V U
T Y
UV DR/AHMED ESAWY

32. • SHOULD BE REPORTED TO THE PATIENT
• REPEAT IN 1 – 2 WEEKS
• SERAIL TV ULTRASOUND are necessary
• OPTION OF CERCLAGE
• BED REST / RESTRICTED ACTIVITY DISCUSSED
• DIFFERENT FOR MULTIPLE GESTATION ?
DR/AHMED ESAWY

33. Funneling of the cervix with the changes in forms T, Y, V, U(correlation between
the length of the cervix and the changes in the cervical internal os).
DR/AHMED ESAWY

34. DR/AHMED ESAWY

35. Cervix length < 25 mm
Protrusion of the membranes
Presence of fetal parts in the cervix or vagina
DR/AHMED ESAWY

36. • If the cervical length is deviated
(defined as greater than 5mm from straight)
then 2 straight lines should be used.
• Usually a short Cx not deviated
• If the cx canal is closed then the only
measurement that is necessary is the cervical
length .
DR/AHMED ESAWY

37. ONE OR TWO MEASUREMENT
DR/AHMED ESAWY

38. If the 
is > 3 mm,
use two
measures
Don’t Trace to Measure the Cervical Length
DR/AHMED ESAWY

39. Role of Ultrasonography in
cerclage
before cerclage – length of cervical canal
width of isthmus
funneling of upper part of cervical canal with protrusion of
the membranes
(when the cervical os (opening) is greater than 2.5 cm, or
the length has shortened to less than 20 mm. Sometimes
funneling is also seen )
DR/AHMED ESAWY

40. Role of Ultrasonography in
cerclage
After cerclage – determine exact site of cerclage,
proximal cervical canal segment length above cerclage
distal cervical canal segment length below cerclage
internal os diameter
funneling if present
protrusion of membranes
DR/AHMED ESAWY

41. Negative U/S can not exclude CI
Positive U/S in routine screen in pregnant
women without history of pregnancy loss are
not necessary at risk but close follow up is
required
DR/AHMED ESAWY

42. 2 images of the same cervix, 20 seconds apart, without and with applying pressure
DR/AHMED ESAWY

43. All Viable, Singleton Pregnancies at
Anatomy Scan
(18 0/7 -23 6/7 Weeks)
Transvaginal Ultrasound for
Cervical Length
Excludes:
Multiples
Cerclage Present
≥25 mm
Normal cervical length
21 – 24.9 mm
Borderline cervical
shortening
≤20 mm
Clinically significant cervical
shortening
MFM Consult for
Counseling and
Intervention
Recommendations
No further screening or
intervention
CL ≤20mm
Repeat Scan
by 23rd Wk
Yes
GA < 23 0/7 wks
No
Yes No
DR/AHMED ESAWY

44. • targeted examinations
Cervical stress test at 15-24 weeks (increasing transfundal intrauterine
pressure while monitoring cervical length and the appearance of funneling is
recommended for the patients with
• history of painless dilatation followed by fetal expulsion in the second
trimester
• conization
• uterine malformations (uterus unicornis, uterus bicornis, uterus didelphys)
• cervical trauma (conization)
• history of spontaneous and therapeutic abortions
• preterm birth before 32 weeks .
DR/AHMED ESAWY

45. • MRI appearance of the cervical incompetence
may demonstrate a higher degree of soft
tissue contrast than ultrasonography.
DR/AHMED ESAWY