Outcome Reporting in Studies Investigating Treatment for Caesarean Scar Ectopic Pregnancy: A Systematic Review.

Background: Caesarean scar ectopic pregnancy (CSEP) is associated with significant maternal and foetal morbidity. However, the optimal treatment remains unknown.

Objectives: The aim of this study was to review outcomes reported in studies on CSEP treatment and outcome reporting quality.

Search strategy: We reviewed 1270 articles identified through searching PubMed, MEDLINE and Google Scholar from 2014 to 2024 using the search terms 'caesarean scar ectopic pregnancy and caesarean scar pregnancy'.

Selection criteria: We included all study types evaluating any form of CSEP treatment, with a sample size of ≥ 50, where diagnosis was described, and the article was in English.

Data collection and analysis: Two authors independently reviewed studies and assessed outcome reporting and methodological quality. The relationship between outcome reporting quality and publication year and journal type was assessed with univariate and bivariate models.

Main results: A total of 108 studies, including 17 941 women, were included. 83% of all studies originated from China. Studies reported on 326 outcomes; blood loss (86%), need for additional intervention (77%) and time for serum hCG to normalise post treatment (69%) were the most common outcomes. A primary outcome was clearly defined in 11 (10%) studies. The median quality of outcome reporting was 3 (IQR 3-4). No relationship was demonstrated between outcome reporting quality and publication year (p = 0.116) or journal type (p = 0.503).

Conclusions: This review demonstrates that there is a wide variation in outcomes reported in studies on CSEP treatment. Development and implementation of a core outcome set by international stakeholders which includes patients is urgently needed to enable high-quality research that is both useful and relevant to patients.