Creatine phosphokinase, a new marker in diagnosis of tubal ectopic pregnancy; A Systematic Review

INTRODUCTION: Creatine phosphokinase (CPK) is an intracellular enzyme found in higher levels in the brain, myocardium, soft muscle and skeletal muscle, as well as the fallopian tube. This review was conducted to evaluate the role of serum CPK in early diagnosis of tubal ectopic pregnancy (EP). METHODS: We performed an electronic literature search in Web of Science, Scopus, Embase and Medline databases and manual search in Google scholar and evaluated papers from the beginning of 1990 to September 2018. The inclusion criteria consisted of cohort, case-control and diagnostic value studies in English or Persian. Two independent researchers used the inclusion and exclusion criteria. In cases where there was doubt about the eligibility of studies, this problem was resolved by consulting a third researcher. After a thorough search, finally, we found 27 papers. However, four of these articles did not have the inclusion criteria and we excluded them from the study. As a result, 24 studies were evaluated. RESULTS: Most studies have approved the use of CPK measurements in EP diagnosis. The main variable measured in most studies was the mean total CPK level. However, there is limited knowledge about the efficacy of measuring CPK levels in EP diagnosis; this review of studies shows positive results regarding use of CPK in EP diagnosis. CONCLUSIONS: The results highlighted the potential benefits of CPK as a marker for early diagnosis of EP.