The Significance of Serum CA-125 Level on the Live Birth Rates of In Vitro Fertilisation in Women with Endometriosis.

Background and

Objectives

To evaluate the significance of serum CA-125 level on the live birth rate of in vitro fertilization (IVF) in women with endometriosis. Materials and

Methods

This retrospective observational study included women with endometriosis who underwent one stimulated IVF cycle. Serum CA-125 levels were measured in archived serum samples collected prior to ovarian stimulation, on the day of ovulation trigger, and during frozen embryo transfer. Serum CA-125 levels were compared between cycles with and without a live birth in both stimulated IVF and frozen embryo transfer cycles, with a subgroup analysis using a cut-off of 35 IU/L.

Results

Within the same patient undergoing the same IVF cycle, serum CA-125 level on the trigger day of the stimulated cycle was significantly lower than the baseline level before stimulation started (35.1 IU/L [21.0-64.5 IU/L] vs. 46.8 IU/L [25.9-104.0 IU/L], p < 0.001), but was higher than that in the frozen embryo transfer cycles (31.7 IU/L [19.9-58.7 IU/L] vs. 27.3 IU/L [18.1-59.9 IU/L], p = 0.041). Serum CA-125 levels were not associated with the live birth rate in the stimulated IVF cycle and frozen embryo transfer cycles. In subgroup analysis, women with serum CA-125 level ≥ 35 IU/L on the trigger day had a significantly higher pregnancy rate from the fresh embryo transfer cycle than those with level < 35 IU/L (adjusted odds ratio 4.126, 95% CI 1.241-13.720, p = 0.021). The cut-off of 35 IU/L did not show significant differences in live birth rate for either stimulated or frozen embryo transfer cycles.

Conclusions

In women with endometriosis, no significant differences in serum CA-125 levels were found between those with and without a live birth in fresh and frozen embryo transfer cycles. In fresh embryo transfer cycles, those with serum CA-125 ≥ 35 IU/L had significantly higher pregnancy rates.