Peritoneal relative to venous serum biomarker concentrations for diagnosis of ectopic pregnancy

To retrospectively analyze the relationships of peritoneal serum relative to venous serum (R (p/v)) ratios for human chorionic gonadotropin, CA-125, and creatine kinase to the ectopic pregnancy (EP).

Intra-abdominal fluid and venous blood samples of 118 subjects with suspected EP were obtained for biomarker measurements. R (p/v-hCG) >1 was considered indicative of EP, and final diagnosis was based on surgical finding of an ectopic chorionic villous or gynecological ultrasound finding of an intrauterine gestational sac.

R (p/v-hCG) and R (p/v-CA-125) were both significantly greater for abortive as compared to ruptured EP and for the absence as compared to presence of active bleeding. However, neither ratio differed significantly between ampullary and isthmic EP. R (p/v-hCG) and R (p/v-CA-125) correlated negatively with hemoperitoneum volume. R (p/v-hCG) exhibited only modest predictive value for rupture. However, with R (p/v-CA-125) as the diagnostic criterion for rupture, sensitivity and specificity were 66.7 and 100%, respectively; in patients initially diagnosed with EP, R (p/v-CA-125) values <22.43 effectively predicted rupture. R (p/v-CK) did not exhibit significant diagnostic value.

R (p/v-hCG) values >1 combined with positive culdocentesis test findings reliably indicate the presence of EP. In patients initially diagnosed with EP, R (p/v-CA-125) values <22.43 predict tubal rupture.