Obstetric outcomes and management after cervical conisation for cervical intraepithelial neoplasia

Abstract

Sir,We are grateful for the reaction to our paper Pregnancy outcome after cervical conisation, a retrospective cohort study in the Leuven University Hospital. 1,2 The limitations of our retrospective study and other published data are clearly discussed in the paper. As women with cervical intraepithelial neoplasia, stage 3 (CIN3) must be treated, the adverse effects on obstetrical outcome in future pregnancies will remain, whether the surgical intervention or factors related to the pathology, or both, are causal. I doubt if a proper randomised trial will ever be possible unless future therapeutical human papillomavirus (HPV) vaccines offer the opportunitiy to compare CIN3 treated medically with CIN3 treated with conisation or ablative therapy. Meanwhile, clinicians better adhere to approved management principles in cases with CIN3, and tailor the size of cones and the area of ablation to the lesion size and geography of the transformation zone in order to minimise the structural damage to the cervix. Obstetricians and their patients have to be aware of the possible adverse effects of a history of CIN3 and/or conisation on pregnancy outcome, especially preterm delivery. It remains unclear how to manage these women in subsequent pregnancies. Future studies should focus on the predictive value of cervical length measurements and the preventive effect of cerclage in cases with short or distended cervical canals. j Obstetric outcomes and management after cervical conisation for cervical intraepithelial neoplasia References Authors' ReplySir, Thank you for your interesting and relevant comments on the association between cervical conisations and obstetric outcomes. 1,2 We agree that a randomised study would be needed to fully establish a cause and effect relationship between previous conisation and obstetrics outcome. However, we only had the option to do a population-based cohort study, as a randomised study in patients with severe cervical dysplasia is not feasible in Danish patients, as neither the patients nor the Danish Ethical Committee would accept any randomisation that included a 'no-treatment' option. Our data were analysed using a wide variety of statistical methods such as adjusted or unadjusted odds ratios, adjusted or unadjusted relative risks, and adjusted or unadjusted hazard ratios. After statistical counselling we ended up using unadjusted and adjusted hazards ratios from Cox analysis. This choice enabled us to include women who were delivered electively preterm because of maternal or fetal pathology, allowing their time to delivery to be included in the analysis. These patients were censored at the time of delivery. However, independent of which statistical method we used, we found the same strong relationship between one or two conisations and preterm birth. We included adjustment for possible confounding factors such as maternal age, smoking status, parity, marital status, and educational level, as stated in the methods section. In the final analysis, only confounding factors that affected the haz...