THE INCOMPETENT CERVIX

Primary failure of the uterine cervix to retain an intrauterine pregnancy until term or the onset of labor (1).

INCIDENCE

• Reported prevalence of 1% and may be responsible for as many as 20% of second trimester miscarriages (2).
• Cervix less than 25 mm in length.

ETIOLOGY

• Idiopathic (most common cause).
• Congenital disorders (congenital mullerian duct abnormalities.
• Congenital (usually associated with diethylstilbestrol exposure) (3).
• Secondary to obstetrical trauma, dilatation and curettage.
• Associated with uterine malformations, increased muscular composition of the cervix (4), congenital inadequacy of the lower uterine segment (5), hereditary (6) e.g. Ehlers-Danlos syndrome.

ULTRASOUND

Link to Ultrasound

CERVICAL CERCLAGE

Link to Cervical Cerclage

COMPLICATIONS

• Premature rupture of membranes.
• Infection due to the premature rupture.

REFERENCES

1. Harris RD, Barth RA. Sonography of the gravid uterus and placenta: Current concepts. AJR 1993;160:455-465.
2. Ludmir J. Sonographic detection of cervical incompetence. Clin Obstet Gynecol 1988;31:101-109.
3. Singer MS, Hockman M. Incompetent cervix in a hormone exposed offspring. Obstet Gynecol 1978;51:625-626.
4. Roddick JW Jr, Buckingham JC, Danforth DN. The muscular cervix: a cause of incompetency in pregnancy. Obstet Gynecol 1961;17:562-565.
5. Trythall SM, Jermias RD. Congenital inadequacy of the lower uterine segment as a cause of habitual abortion. Int J Fertil 1961;6:67-72.
6. Ranney B. Congenital cervical incompetence in primigravidas. Am J Obstet Gynecol 1963;86:52-65.