Incompetent cervix: pathogenesis, diagnosis and treatment

The incompetent cervix is a diagnostic dilemma. There are no well-defined or strict criteria to diagnose cervical incompetence, and therefore the indications for treatment are not always clear. Forty years ago, when the basic methods of treatment were first described, the diagnosis seemed relatively simple and the treatment acceptable. There have been very few large, prospective, randomized, well-controlled studies to determine the efficacy of the various surgical methods. Liberal use of cerclage procedures in situations of moderate risk for premature delivery or as prophylactic measures in multiple pregnancy does not appear to improve outcome as judged by prematurity or fetal survival. At the present, fetal survival cannot be a measure of the success of a surgical procedure because so many other factors play a role in outcome, such as the quality of obstetrical and neonatal care. Therefore, outcome of surgical procedures should be judged by more objective criteria, such as prolongation of pregnancy (in weeks) and birth weight. The methods that would allow making an unequivocal and objective diagnosis of incompetent cervix are not yet available. Until we reach this goal, the subject of cervical incompetence and effectiveness of its treatment will remain challenging and elusive.