Clinical and Experimental Obstetrics & Gynecology (CEOG) is published by IMR Press from Volume 47 Issue 1 (2020). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with S.O.G.
Introduction: Based on the characteristics of the internal cervical os and the cervix as a whole, during continuous controllable balloon dilatation, it can be said that the uterine cervix behaves as a sphincter, although it does not have the anatomical structure of a sphincter. Material and Methods: The system for continuous and controllable balloon dilatation is based on the hydraulic balloon dilator. The main advantage of the continuous and controllable balloon dilatation is that it provides the physician with the ability to monitor and control the process of cervical dilatation. This study included 42 patients, in whom the dilatation process was monitored and analysed prior to the termination of an unwanted pregnancy. Statistical analyses were performed using SPSS software. A normal distribution of continuous data was tested using the Kolmogorov-Smirnov test. The correlation between observed parameters was analysed using Pearson’s and Spearman’s correlation coefficients. Results: During dilatation with continuous and controllable balloon dilatation system, a sudden drop in pressure and volume of the fluid in the balloon extension occurred. This phenomenon was labelled as the breaking point of the cervix, or the point when the cervix stops resisting dilatation. There was no statistically significant correlation between the cervical breaking point and the number of previous births or the number of previous miscarriages or abortions. Discussion: The uterine cervix behaves as a sphincter during continuous and controllable balloon dilatation, which is verified by the existence of a cervical breaking point. The breaking point values did not vary with the number of previous cervical dilatations, whether artificial or physiological.