Value of serum CA-125 concentrations as predictors of pregnancy in assisted reproduction cycles

The means by which endometrial receptivity influences conception rates in assisted reproductive technology (ART) is poorly understood. As the glycoprotein CA-125 is a product of human endometrium and is measurable in the peripheral circulation, it was investigated whether it might serve as an indicator of endometrial receptivity and predictor of pregnancy. In this prospective study, serum CA-125 concentrations of 75 ART cycles were measured 1 day before and on the day of human chorionic gonadotrophin (HCG) administration, and on the day of oocyte retrieval. These women did not have endometriosis and were induced by long-protocol gonadotrophin-releasing hormone analogue. Pregnancy was achieved in 35 (46.7%) cycles, but not in 40 cycles (53.3%). Serum CA-125 concentrations 1 day before and on the day of HCG administration and on the day of oocyte retrieval were significantly higher in cycles with pregnancy than in those without pregnancy (P < 0.05). It was noted that CA-125 concentrations on the day of oocyte retrieval were the best predictors of pregnancy, with concentrations >10 IU/ml having an accuracy of 86.6% for pregnancy. In conclusion, in intracytoplasmic sperm injection cycles, women with high serum CA-125 concentrations (>10 IU/ml) on the day of oocyte retrieval had very high pregnancy rates.