Premature Cervical Dilatation (Incompetent Cervix) Notes

Premature Cervical Dilatation Overview
  • Definition: Previously termed incompetent cervix; a condition where the cervix dilates prematurely, making it unable to retain a fetus until term (Kogan, Ben-Shushan, & Pernoll, 2007).
  • Incidence: Occurs in approximately 1% of women.
  • Symptoms:
    • Usually painless
    • Initial signs may include show (a pink-stained vaginal discharge) or increased pelvic pressure.
    • Followed by rupture of membranes (ROM) and discharge of amniotic fluid.
    • Possible uterine contractions leading to preterm birth.
Timing and Risk Factors
  • Common Occurrence: Typically occurs around week 20 of pregnancy when the fetus is too immature to survive.
  • Associated Factors:
    • Increased maternal age
    • Congenital structural defects
    • Trauma to the cervix, such as from cone biopsies or repeated D&Cs (Dilation and Curettage).
  • Diagnosis: Can be detected via ultrasound but is often diagnosed post-pregnancy loss.
Surgical Intervention
  • Cervical Cerclage: A surgical option (Fox & Chervenak, 2008) that can be performed after a previous loss due to cervical dilatation to prevent recurrence in future pregnancies.
    • Procedure Timing: Typically placed at approximately 12-14 weeks of gestational age, after confirming a healthy fetus via ultrasound.
Types of Cerclage Procedures
  • McDonald Procedure:
    • Nylon sutures are applied horizontally and vertically across the cervix and tightened to reduce the cervical canal diameter to a few millimeters.
  • Shirodkar Technique:
    • Involves threading sterile tape in a purse-string manner under the submucous layer of the cervix to achieve a closed cervix.
Surgical Techniques and Considerations
  • Cerclage can be performed either
    • Transvaginal: Via the vaginal route.
    • Transabdominal: For women with recurrent pregnancy loss, leaving sutures in place for cesarean births.
Post-Operative Care
  • Removal of sutures usually occurs between weeks 37 to 38 of pregnancy to allow vaginal delivery.
  • Women may need an emergency cerclage if they have cervical dilatation but intact membranes.
Monitoring and Prognosis
  • Women who have experienced premature cervical dilatation should be asked about past cervical operations when reporting painless bleeding, which might indicate sutures in place.
  • Prognosis: The success rate of cerclage for ensuring a successful pregnancy is 80% to 90%.
  • After cerclage, women typically remain on bed rest for a few days to alleviate pressure on the sutures and can usually resume normal activities and sexual relations afterward.
References
  • Maternal and Child Health Nursing: Care of the Childbearing and Childrearing Family; 8th Edition, Pillitteri, Adele; Wolters Kluwer Lippincott Williams & Wilkins; 2017.
Conclusion
  • Acknowledging the complexities associated with premature cervical dilatation is essential for effective management and ensuring favorable pregnancy outcomes.