Objective: To compile existing knowledge on the level of cervical regeneration (detected by ultrasound) after loop electrosurgical excision procedure (LEEP) and to suggest research protocol for further studies.
Methods: We conducted a literature search of Medline, Web of Science, Scopus, and Cochrane databases using the keywords "cervix" and "regeneration" without year restrictions. Our eligibility criteria included studies that analysed cervical volume and length regeneration using ultrasound. A literature review was conducted following PRISMA guidelines and registered in PROSPERO (reg. no. CRD42021264062). Information about the studies was extracted from each analysed study on an Excel datasheet and the average regeneration with standard deviation was calculated. All included studies' possible biases were assessed by the National Institutes of Health's (NIH) quality assessment tool.
Results: The literature search identified 802 papers and four trials (n = 309) that met our criteria. They investigated cervical length and volume regeneration after LEEP using ultrasound, concluding that there is a profound regeneration deficit. Average cervical length regeneration after 6 months was 83.4% (±10.8%) and volume regeneration was 87.4% (±6.1%). All analysed studies had their biases; therefore, based on the conducted studies' protocols, we present a CeVaLEP research protocol to guide high-quality studies.
Conclusion: After LEEP, there is a cervical regeneration deficit. There is a lack of high-quality studies that assess cervical volume regeneration and its relation to obstetrical outcomes. There is a gap in the field and more research is needed to define the prenatal risks related to cervical regeneration.
Keywords: HPV; cervical intraepithelial neoplasia; cervix uteri; cone resection; microbiota; preterm delivery; treatment.