Cervical Incompetence

1. Cervical Incompetence Dr.Ashraf K. fouda Domiatte General Hospital

2. DEFINITION • Condition in which the cervix fails to retain the conceptus during pregnancy. • There are arguments about the occurrence and incidence of incompetent cervix

3. Prevalence Affects around 1% of pregnant patients

4. Cervical incompetence Cervical incompetence has long been recognized as a potential cause of preterm delivery & recurrent mid trimister abortionns.

5. Cervical incompetence It is believed that cervical incompetence is the cause of 20 - 25 % of all second trimester losses

6. AETIOLOGY • Idiopathic (most cases). • Congenital disorders (congenital mullerian duct abnormalities eg. Septate uterus, Bicornuate uterus). • DES exposurein utero. • Connective tissue disorder(Ehlers- Danlos syndrome). • Surgical trauma : • Conization,( resulting in substantial loss of connective tissue) or • Traumatic damage to the structural integrity of the cervix : (repeated forced cervical dilatation associated with D&C).

7. AETIOLOGY The cervical competence is an active, not passive, phenomenon, and it is a specific entity involving not just an abnormality or defect of cervical collagen, but is also due to either: • Absence of the usual cervical musculature in cases of congenital cervical incompetence, or • Injury or damage to the cervical musculature caused by previous trauma.

8. Symptoms Women with incompetent cervix typically present with "silent" cervical dilatation (i.e., with minimal uterine contractions) between 16 and 28 weeks of gestation.

9. Symptoms • Patient present with significant cervical dilatation (2 cm or more) and minimal symptoms. • When the cervix reaches 4 cm or more, active uterine contractions or rupture of membranes may occur.

10. Pathogenesis • The function of the cervix during pregnancy depends on the regulations of connective tissue metabolism. • Collagen is the principal component in the cervical matrix, others are: (proteoaminoglycans, elastin and glycoproteins, like fibronectin).

11. Pathogenesis The biochemical events implicated in the cervical ripening are: • Decrease in total collagen content, • Increase in collagen solubility and • Increase in collagenolytic activity.

12. Diagnosis • It is a clinical diagnosis marked by gradual, painless dilatation and effacement of the cervix with membranes visible through the cervix. • This history establishes the diagnosis, eventually, women with this cervical status may develop membrane rupture & labor. • Short labors with the delivery of an immature fetus or loss of the pregnancy at progressively earlier gestational ages in successive pregnancies is characteristic of reduced competence.

13. Diagnostic Criteria • Historical factors • History of painless cervical dilatation with preterm delivery • History of forceful cervical dilatation and evacuation • History of obstetric trauma: cervical lacerations, prolonged second stage followed by cesarean • Prior cervical surgery: cone, loop • DES exposure in utero • Cervical sonography • Short cervical length • Cervical funneling

14. IMPROVMENTS IN DIAGNOSIS • The diagnosis is at present largely subjective and retrospective. • If possible, an objective (i.e. measurable) diagnosis, made before pregnancy or in the early stages (first or early second trimester) would provide : • An accurate incidence of cervical incompetence, • Allow treatment to be targeted appropriately and • Also provide the basis for definitive trials of treatment.

15. Diagnosis • Dilators or balloons to determine cervical resistance and/or hysterosalpingograms to measure the width of the cervical canal between pregnancies are neither sensitive nor specific. • Digital examination of the cervix is highly subjective. • Sonography has provided a reproducible method of evaluating the cervix.

16. Ultrasonography • Initial use of ultrasound to observe the cervix was transabdominal but the necessity for a full bladder to visualize the cervix elongates the cervix to such a degree as to make objective, reproducible measurements difficult. • The development of transvaginal scanning (TVS) allowed for accurate cervical measurements with an empty bladder and no distortion .

17. Transvaginal ultrasound 'funneling' or 'breaking' ofthe internal cervical os ( at rest or particularly in response to transabdominal pressure on the uterine fundus ) is the ultrasonographic appearance of cervical incompetence .

18. Cervical measurements

19. Transvaginal ultrasound • Provide a significant advance in the diagnosis of cervical incompetence • In contrast to the hysteroscopic evaluation of the cervix, it is : non-invasive, repeatable over time and can be performed during pregnancy.

20. Sonographic findings • 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).(Trust Your Vaginal Ultrasound) • Cervix length < 25 mm • Protrusion of the membranes. • Presence of fetal parts in the cervix or vagina

23. 2 images of the same cervix, 20 seconds apart, without and with applying pressure:

24. Am J Obstet Gynecol 1997;177:660-5. Sonographic serial evaluation ( every two weeks) of the cervix for funneling and shortening in response to transfundal pressure has been found to be useful in the evaluation of incompetent cervix.

25. TREATMENTS • Surgical repair of the cervix using a vaginal or abdominal approach. • Other alternatives that have been considered have included : • Bed rest, for which no trial has been conducted and for which little evidence of effectiveness exists, and • The use of vaginal pessaries to elevate and close the cervix.

26. TREATMENTS The initial descriptions of cervical cerclage for cervical incompetence came with Shirodkar and McDonald in the 1950s, when both developed techniques for physical support for what was presumed to be a structurally weak cervix.

27. Surgical approaches to cervical incompetence is, at present, the mainstay of treatment

28. Am J Obstet Gynecol 1982 Mar 1;142(5):506-12 ,Obstet Gynecol 1989 Feb;73(2),Am J Obstet Gynecol 1993 Nov;169(5):1125-9  PMID: 8238171,J Reprod Med 1994 Nov;39(11):880-2 PMID: Cerclage is not indicated solely based on risk factors or prior cerclage placed for doubtful indications.

30. Prophylactic Cerclage • Prophylactic cerclage sutures (Shirodkar, McDonald )may be placed at 12 to 16 weeks' gestation. • Do not use tocolytics at the time of prophylactic cerclage, but give perioperative antibiotics. • Intercourse, prolonged standing (>90 minutes), and heavy lifting are omitted following cerclage. • Follow these patients with periodic vaginal sonography to assess stitch location and funneling.

31. Prophylactic Cerclage • No additional restrictions are recommended as long as the stitches remain within the middle or upper third of the cervix without the development of a funnel, and the length of the cervix is greater than 25 mm. • For patients who have not been successful with a vaginal suture despite aggressive care and sonographic surveillance, a transabdominal cerclage may be appropriate.

32. Emergency Cerclage • Care of the patient with newly detected reduced cervical competence in the second trimester is both difficult and controversial. • When the diagnosis is made before cervical dilatation has occurred and when there is still 10 to 15 mm or more of cervical length, admit the patient for 24 hours of treatment with perioperative indomethacin and broad-spectrum antibiotics before placing the cerclage sutures, and observe the patient for 48 to 96 hours postoperatively.

33. Emergency Cerclage • However, if the cervix has dilated to allow visualization of the membranes, the patient may remain hospitalized for several days after cerclage placement. • The prognosis for these patients is better than generally expected, with many women delivering a "viable" (usually defined as >1,000 g) infant, but aggressive therapy may be required to achieve these results. • The prognosis is influenced by the gestational age at the time when the suture is placed.

34. Emergency Cerclage In the case of advanced dilatation with bulging membranes, several techniques may be helpful: • Pre cerclage amniocentesis to remove sufficient fluid to reduce the bulging membranes can be helpful. • Overfilling the bladder with 1,000 ml of saline may help by elevating the membranes out of the operative field, but may also obstruct the surgeon's view. • Place a Foley catheter balloon inside the cervix, and overfill it with at least 50 ml of saline to gently push the membranes out of the lower segment. The cerclage suture can then be placed and tied as the balloon fluid is evacuated.

35. Emergency Cerclage • Cerclage is rarely performed after 24 to 25 weeks of pregnancy. • The great risk of inducing PROM or preterm labor and the ability to prolong gestation with bed rest and suppressive medications argue against surgical intervention in such cases. • The cerclage is removed at 37 weeks' gestation or at the onset of labor.

36. Indication for cerclage • History compatible with incompetent cervix AND • Sonogram demonstrating funneling OR • Clinical evidence of extensive obstetric trauma to cervix ACOG Criteria Number 17 October 1996, ACOG Criteria Number 18 October 1996

37. Contraindications 1.Uterine contractions. 2.Uterine bleeding 3.Chorioamnionitis 4.Premature rupture of membranes 5.Fetal anomaly incompatible with life

38. Cerclage procedures There are five different techniques for performing the cerclage: • McDonald procedure • Shirodkar operation • Wurm procedure (Hefner cerclage) • Transabdominal cerclage • Lash procedure The two most common are the McDonald and Shirodkar.

39. McDonald procedure • The McDonald procedure is done with a 5 mm band of permanent suture is placed high on the cervix. • This is indicated when there is significant effacement of the lower portion of the cervix. • It is generally removed at 37 weeks, unless there is a reason to remove it earlier, like infection, preterm labor, premature rupture of the membranes, etc. • It is also shown that this has very little impact of the chance for vaginal delivery.

40. McDonald operation • The McDonald technique requires no bladder dissection, and the cervix is closed using four or five bites with the needle to create a purse string around the cervix.

41. McDonald operation

43. Shirodkar operation • The Shirodkar is also a frequently used technique. • However, this was previously a permanent purse string suture that would remain intact for life. • There are physicians performing modified techniques, where the delivery does not necessarily have to be by cesarean, nor the suture left intact.

44. Shirodkar operation • Place the suture as near the internal os as, opening the anterior fornix and dissecting away the adjacent bladder, before placing the suture submucosally, tied anteriorly and the knot buried by suturing the anterior fornix mucosal opening. • The original intention with the Shirodkar method was to leave the suture in place and aim for delivery by caesarean section.

45. Shirodkar operation

46. Shirodkar and McDonald • Both initially started suturing with catgut, but Shirodkar turned to fascia lata and McDonald turned to ( 0 )silk as they realized the importance of a permanent cervical support. • One significant difference since then has been the present day use of Mersilene tape as the suture material.

47. Shirodkar and McDonald • Both the McDonald and Shirodkar cervical sutures are equally effective as a vaginal approach to cervical cerclage. • McDonald suture is generally easier to perform with no major difference in success.

48. Wurm procedure • The Hefner cerclage, also known as the Wurm procedure, is used for later diagnosis of the incompetent cervix. • It is usually done with a U or mattress suture, and is of benefit when there is minimal amounts of cervix left.

49. Trans abdominal cerclage One further development in the 1960s was the description of the transabdominal cerclage by Benson and Durfee in 1965 a technique now largely used after the failure of vaginal cerclage procedures or in the presence of congenital anomalies, particularly those produced by diethylstilboestrol exposure.

50. Trans abdominal cerclage The original intention with the transabdominal approach was that the suture was inserted between pregnancies or in early pregnancy, and left in situ for the rest of the woman's reproductive life, delivery being undertaken by caesarean section for each pregnancy.