Local ablation or excision of the transformation zone has been highly successful in treating high-grade CIN and greatly reduces the risk of progression to invasive carcinoma but it is not itself without risk (Kyrgiou 2014).
It is probable that the increase in second trimester miscarriages due to premature rupture of membranes reported after excision biopsy is related to the size of biopsy, making knife cone biopsy a greater risk than LLETZ (Khalid et al. 2012). Although the risk with LLETZ relates to excisions deeper than 10 mm (Castanon et al. 2013), it is clearly important to avoid unnecessary excision treatment of women in early reproductive life.
Thus cytological over-diagnosis is just as important as under-diagnosis, which is the reason why rigorous quality control measures are essential
Potential risks of treatment of high-grade CIN