Chapter 202 Cervical Incompetence
INTRODUCTION
Description: Cervical incompetence is characterized by asymptomatic dilation of the internal os during pregnancy. This generally leads to dilation of the entire cervical canal during the second trimester with subsequent risk of rupture of the membranes, expulsion of the fetus, or both.
Prevalence: One of 54 to 1 of 1842 pregnancies (as a result of uncertain diagnostic criteria); appears to be declining.
ETIOLOGY AND PATHOGENESIS
Causes: Iatrogenic (most common); damage from cervical dilation at the time of dilation and curettage (D&C) or other manipulation, damage caused by surgery (conization). Congenital tissue defect, uterine anomalies (uterus didelphys), obstetric lacerations, in utero exposure to diethylstilbestrol (DES).
