Cervical incompetence. A re-evaluation.

Abstract

The concept of “cervical incompetence-late abortion” is neither complex nor mysterious. The cervix is fundamentally a connective tissue structure whose major function is to retain the conceptus within the uterus after 14 weeks' gestation; neither the internal os, isthmus, lower uterine segment nor any other structure is concerned. If the fibrous cervical ring is sufficiently intact when uterine distention begins at about 14 weeks, the pregnancy will continue; if not, abortion follows, the timing varying inversely with the extent of the defect. A classification is presented of the three fundamental types of cervical incompetence, and diagnosis and management are outlined.