Evaluation of maternal plasma creatine kinase activity as a marker of abnormal early pregnancy

Abstract

We have tested the value of maternal plasma creatine kinase activity for diagnosing ectopic pregnancies obtained after in-vitro fertilization and embryo transfer. Plasma creatine kinase was assayed in 57 patients: 20 normal, 23 miscarriages and 14 ectopic pregnancies, for a total of 240 samples. All values were in the lower part of the normal range except only one in a miscarrying patient. A statistically significant difference was observed for a cut-off value of 45 IU/l between normal and ectopic pregnancies. However, for this cut-off point, the measurement of plasma creatine kinase activity had a sensitivity of 0.50 and a specificity of 0.76 for the diagnosis of ectopic pregnancy. The positive predictive value was 0.69. Creatine kinase activity measurements are thus of no practical value in this particular population, in which an early and specific marker of ectopic implantation would be of paramount interest. The association of human chorionic gonadotrophin (HCG) determinations and ultrasound scanning of the pelvis still remain the best paraclinical support for an early diagnosis of ectopic implantation.

Do levels of serum cancer antigen 125 and creatine kinase predict the outcome in pregnancies of unknown location?

“…Maternal CK levels have been previously evaluated in confirmed EP (Korhonen et al, 1996;Qasim et al, 1996;Vandermolen and Borzelleca, 1996;Zorn et al, 1997). CK is a non-specific marker of smooth muscle damage.…”

“…One theory is that damage to the fallopian tube in EP is sufficient to cause an increase in serum Downloaded from https://academic.oup.com/humrep/article-abstract/20/12/3348/2913666 by guest on 13 June 2019 CK (Lavie et al, 1993). Although some studies have demonstrated that maternal serum CK levels can be an important biochemical marker for the diagnosis of EP (Chandra and Jain, 1995;Duncan et al, 1995), the general view is that maternal serum CK concentrations do not reliably predict EP (Korhonen et al, 1996;Qasim et al, 1996;Vandermolen and Borzelleca, 1996;Zorn et al, 1997).…”

Evaluation of serum creatine kinase in ectopic pregnancy with reference to tubal status and histopathology

“…The histopathology of ectopic gestations was not studied in any of the subsequent reports which challenged the findings of Lavie et al 2 , as they showed creatine kinase levels in ectopic pregnancy not to differ from levels observed in controls 3–5 , 7 . Careful reading of these reports can suggest the tubal status of the cases studied.…”

“…These investigators reported higher mean creatine kinase levels in ectopic pregnancy compared with controls with normal intrauterine pregnancies or missed abortions, and deduced that creatine kinase levels above a cutoff of 45iu/L were 100% sensitive for the diagnosis of this condition. Their findings, however, could not be reproduced by most subsequent reports 3–5 , while few other studies, which found similarly higher creatine kinase levels in ectopic pregnancy, also pointed out significant overlap with controls, and concluded that creatine kinase was an unreliable marker for ectopic pregnancy 6,7 .…”

“…Careful reading of these reports can suggest the tubal status of the cases studied. Qasim et al 3 and Zorn et al 7 followed up infertile women newly achieving pregnancy in order to identify cases with tubal implantation, which therefore are likely to have been diagnosed at an early stage, and possibly before tubal rupture. Most of the cases included in the series by Korhonen et al 5 were likely unruptured as well, as these investigators chose to evaluate mostly asymptomatic women with a suspicion of ectopic pregnancy, or women at high risk of ectopic pregnancy and therefore admitted for screening.…”