Comparative fertility and pregnancy outcomes after local treatment for cervical intra-epithelial neoplasia and stage 1a1 cervical cancer: protocol for a systematic review and network meta-analysis from the CIRCLE Group

Introduction: There are several local treatment methods for cervical intra-epithelial neoplasia that remove or ablate a cone-shaped part of the uterine cervix. There is evidence to suggest that these increase the risk of preterm birth and that this is higher for techniques that remove larger parts of the cervix, although the data is conflicting. We present a protocol for a systematic review and network meta-analysis that will update the evidence and compare all treatments in terms of fertility and pregnancy complications. Methods and Analysis: We will search electronic databases (CENTRAL, MEDLINE, EMBASE) from inception till October 2019, in order to identify randomised controlled trials (RCTs) and cohort studies comparing the fertility and pregnancy outcomes amongst different excisional and ablative treatment techniques and/or to untreated controls. The primary outcome will be preterm birth (PTB; <37weeks). Secondary outcomes will include severe or extreme PTB, prelabour rupture of membranes, low birth weight (