Comparing Two Soft Embryo Transfer Catheters: Results of Patients that Received Oocytes from the Same Donor

We compared the efficacy of two different soft catheters on pregnancy rates and designed this study to remove factors that could interfere in the results, i.e., oocyte/embryo quality, endometrial preparation and operator interference. A total of 68 patients undergoing fresh embryo transfer, in oocyte donation cycles were prospectively studied. Every two patients received oocytes from the same donor and were sequentially allocated to either the Frydman or Sidney IVF catheter. Duration of endometrial preparation, number of oocytes, fertilization rate and transferred embryos were similar in both groups. The overall pregnancy rate was 45.5% (31/68), 10 in the Frydman catheter group (29.4%) and 21 in the Sidney IVF catheter group (61.7%). Clinical pregnancy rate was significantly higher in patients who used Sidney IVF catheter compared to those who used Frydman catheter. Out of the 34 pairs of patients, there were 19 discordant pairs. In four cases pregnancy occurred only in the Frydman catheter group and in 15 cases only in the Sidney catheter group. The other 6 pregnancies occurred in patients of both groups (p = 0.02). The choice of embryo transfer catheter may affect the outcome of ART cycles as our study suggests that some soft catheters have better results than others.