Yayla Abide C, et al. - Researchers performed a comparison of embryo transfer (ET) technique based on catheter rotation during its withdrawal in cases with unexplained infertility in a prospective, randomized trial. On randomizing 200 intracytoplasmic sperm injection (ICSI) patients undergoing ET with cleaving or blastocyst-stage fresh embryos into 2 groups (cases with (n = 100), and without (n = 100) catheter rotation during its withdrawal), they noted increased pregnancy and clinical pregnancy rates in association with catheter rotation during its withdrawal. However, the difference in ongoing pregnancy rates did not reach statistical significance.