Evaluation of serum CA 125 concentrations as predictors of pregnancy with human in vitro fertilization

Objective: To determine if CA 125, a product of human endometrium, may be an indicator of early endometrial function. To test this hypothesis we examined CA 125 concentrations before oocyte retrieval in IVF cycles. Design: Retrospective data analysis of 111 consecutive IVF cycles. Setting: Tertiary care academic medical center. Patients: All women who received luteal leuprolide acetate (LA) suppression followed by hMG for IVF and had sera available for analyses were entered into the study. Main Outcome Measure: Serum CA 125 was measured in the previous luteal cycle, day 7 of hMG, day before, and day of hCG administration. Twelve other variables were analyzed. Results: Fifty-six cycles (47 women) qualified for evaluation and included 25 pregnant cycles (45%) and 31 nonpregnant cycles. Higher serum CA 125 concentrations were associated with pregnancy in both endometriosis and nonendometriosis subgroups. CA 125 values on the day of hCG administration were the best predictors of pregnancy, with levels greater than or equal to 16 U/mL having a sensitivity of 72%, specificity of 97%, and a positive predictive value of 95% for pregnancy. The other variables were not predictive of pregnancy. Conclusions: With a LA and hMG stimulation protocol, increased CA 125 concentrations before retrieval are associated with very high pregnancy rates. The source(s) of the serum CA 125, although as yet undetermined, may be of endometrial origin. The study supports further evaluation of CA 125 concentrations in IVF as a preretrieval predictor of pregnancy.