Effect of atosiban on in vitro fertilization pregnancy outcome among women with endometriosis in presence or absence of adenomyosis

This study aimed to assess the effect of atosiban on in vitro fertilization (IVF) pregnancy outcome among women with both endometriosis and adenomyosis, and compared it to that of patients with endometriosis but without adenomyosis and that of patients with tubal factor only. 106 infertile women (176 embryo transfers) from a medical center in Taiwan were included in the analysis, where 34 (54), 34 (66), and 38 (56) cases (embryo transfers) were endometriosis without adenomyosis, endometriosis with adenomyosis, and tubal infertility factor only, respectively. Adenomyosis morphologies were classified using an ultrasound-based classification system. The logistic generalized estimating equation model was used to analyze the association between atosiban use and pregnancy outcomes. The crude pregnancy rates for the endometriosis-only group were significantly higher than those for the endometriosis + adenomyosis group (i.e., biochemical pregnancy: 50.0% versus 29.7%, p = 0.041; ongoing pregnancy: 35.2% versus 16.9%, p = 0.038). Significantly higher chances of biochemical pregnancy and ongoing pregnancy among endometriosis patients without adenomyosis versus those with both endometriosis and adenomyosis were found (odds ratios [95% confidence intervals]: 2.981 [1.307, 6.803]; p = 0.009, 2.694 [1.151, 6.304]; p = 0.022). A significant positive association between atosiban use and biochemical pregnancy existed among endometriosis cases without adenomyosis (a 2.43-fold [1.01, 5.89] increase in successful pregnancy; p