Endpoint The primary outcome was live birth delivery rate. Statistical analysis Analysis was performed according to the intention to treat. For descriptive statistics, we used means±SD. Continuous variables were analyzed by the t-test for independent samples. Categorical variables were analyzed by chi-square test. All tests were two-sided, and a P value of less than 0.05 was considered to indicate statistical significance. Using group sequential methods, we calculated that the enrolment of 447 patients in each group would give the study a statistical power of 80% to detect an absolute difference of 10% in the delivery rate between the groups at an alpha level of 0.05 with the use of a two-sided z-test.