The cerclage in 1983.

During a 10-year period in the authors' Hospital 246 cerclages have been performed for treating uterine cervix insufficiency (UCI). Their findings have confirmed that previous mid-trimester abortion is an indication for cerclage, and in patients with "silent opening" of the cervix five times better results are expected than in open uterine cervix as a result of contractions. Insufficiently functioning uterine cervix shows decreasing ability of holding the foetus with an increasing weight during pregnancy. This phenomenon is caused by physical vectors of strength. Due to local cervical tension, prostaglandins (PG) are released. PG transforms the refracter uterus to a reactive organ. This is initially manifested in a long-lasting increase in uterine tone. Later it is a further stimulus to the insufficient UC resulting in excessive PG release.