Background: This study was done to test the hypothesis that intrauterine insemination (IUI) using a soft-tip catheter results in a higher live birth rate than IUI using a hard-tip catheter.
Methods: Five hundred and forty patients were randomized into those inseminated with a soft-tip catheter (group 1, n = 267) and those inseminated with a hard-tip catheter (group 2, n = 269). Four patients were excluded. Main outcome measures included pregnancy rate and live birth rate per cycle.
Results: Both groups were similar with regard to female age, duration of infertility, ovarian stimulation and sperm quality. No significant differences were observed between group 1 and group 2 regarding clinical pregnancy rate per cycle (20 versus 19%), live birth rate per cycle (15 versus 14%), multiple live birth rate per cycle (4 versus 6%) and multiple live birth per total of live births (5 versus 8%, overall 6%), respectively.
Conclusion: Our hypothesis that IUI using a soft tip catheter results in a higher live birth rate per cycle than IUI using a hard-tip catheter was not confirmed in this study. Multiple live birth rate after treatment with low-dose gonadotrophins and IUI can be kept low (6%).