The effects of surgery for endometriosis on pregnancy outcomes following in vitro fertilization and embryo transfer: a systematic review and meta-analysis

To review the literature about the effect of endometriosis on in vitro-fertilization and embryo-transfer (IVF-ET).

A search in EMBASE, MEDLINE, ClinicalTrial.gov, reference lists from 2000 to 2013 was conducted. Inclusion criteria were: endometriosis confirmed with histologic examination, women undergoing IVF-ET, endometriosis treated or diagnosed by surgery. Women undergoing IVF-ET after surgical removal of endometriosic implants, or a surgical diagnosis of endometriosis without its removal, were compared to women without endometriosis. Main outcomes were clinical pregnancy and delivery rates.

Thirteen studies were selected, including 980 women with endometriosis and 5934 controls. Clinical pregnancy rate was lower in women with endometriosis than in controls (OR 0.65; 95 % CI 0.44–0.96), but delivery rate was similar (OR 1.17; 95 % CI 0.69–1.98). When surgery was operative, clinical pregnancy rate after IVF-ET was lower in endometriosis than controls (OR 0.54; 95 % CI 0.34–0.85), but delivery rate was similar (OR 1.12; 95 % CI 0.60–2.07). When surgery was diagnostic, clinical pregnancy (OR 1.15; 95 % CI 0.46–2.84) and delivery rates (OR 1.65; 95 % CI 0.36–7.45) did not differ between the groups. Site of endometriosis was not related to IVF-ET outcomes. Clinical pregnancy rates were similar between stage I-II and controls (OR 0.99; 95 % CI 0.63–1.56) but lower in stage III-IV than controls (OR 0.45; 95 % CI 0.29–0.70), whereas delivery rate was not associated with stage.

In the presence of endometriosis, the clinical pregnancy rate after IVF-ET is lower than in controls. The prognosis is better for mild endometriosis compared with more advanced stages. Even after surgical removal of endometriosis, IVF-ET results remain worse than in controls.