Effect of endometriosis on IVF/ICSI outcome:: stage III/IV endometriosis worsens cumulative pregnancy and live-born rates

BACKGROUND: Women with endometriosis often need IVF to conceive-most women need several cycles of treatment. METHODS: To evaluate the impact of moderate to severe endometriosis on cumulative IVF outcome, we carried out an observational study on 98 consecutive women who underwent IVF or ICSI treatment and had endometriosis diagnosed by laparoscopy or laparotomy and classified as minimal to mild endometriosis (American Society for Reproductive Medicine I/II) (n = 31) or moderate to severe endometriosis (American Society for Reproductive Medicine III/IV) (n = 67). The reference group consisted of 87 consecutive women with tubal infertility. The main outcome measures were cumulative pregnancy and live birth rates. RESULTS: There was a significantly lower pregnancy rate per fresh embryo transfer after pooled cycles (1-4) among women with stage III/IV endometriosis (22.6%) compared to stage I/II group (40.0%) or tubal infertility (36.6%). After 1-4 IVF/ICSI treatments, including frozen embryo transfer, 56.7% of the women with stage III/IV endometriosis were pregnant and 40.3% gave birth. The corresponding values were 67.7/55.8% when endometriosis was stage I/II and 81.6/43.7% in the controls respectively. CONCLUSION: Stage III/IV endometriosis means a worse prognosis for IVF/ICSI treatments compared to milder stages or tubal factors. Lower implantation and multiple pregnancy rates offer some support to our practice to continue two embryo transfers in this group.