Does the embryo transfer (ET) associated air-bubble movement in donor egg IVF recipients predict a successful outcome?

Abstract

In cases of pregnancy achieved through ET, approximately 80% of embryos implant in areas to which they initially are transferred and the exact area of embryo placement in the uterine cavity can be localized precisely by trans-abdominal ultrasound guided ETs. Recent literature suggests that a shallow ET improves pregnancy rates. But the embryos don’t seem to retain their place of deposition at the time of ET. We observed a transient motion of the ET associated air-bubbles and performed this prospective study to determine if this air-bubble movement at the time of ETs can predict a successful outcome. A prospective multi-center comparative study. Trans-abdominal ultrasound guided embryo transfers were performed in 123 consecutive donor egg recipients receiving identical hormonal replacement therapy. All ETs were done by the first author using the same ET catheter (Wallace, UK) and the same Culture Media volume (40–50 micro litres). Observation was made of the embryo transfer catheter placement in relation to the endometrial surface and uterine fundus during embryo transfer. Ultrasound-guided tracking of embryo-associated air within the uterine cavity was done immediately after the piston was depressed at the time of embryo deposition. The air-bubble either moved up or down. The Endometrial thickness, the number of embryos transferred and the number of Grade A embryos was not significantly different in the two arms. The air-bubble movement was upwards (Group A) towards the fundus in 66 ETs compared to a downward movement (Group B) in 57 transfers. No movement of embryo-associated air out of the uterine cavity, either into the cervix or the intramural portion of the Fallopian tube, was seen. The Clinical Pregnancy / Embryo Transfer was similar in both Groups; 50% in Group A versus 49.12% in Group B. There was surprisingly one ectopic pregnancy seen in Group B. The Multiple gestation rate/embryo transfer was 15.15% in Group A versus 15.52% in Group B. The Total Implantation Rate/Embryo Transferred was 22.22% in Group A compared to 19.50% in Group B. The movement of the ET associated air-bubble or the final position of embryo-associated air is unlikely to be a factor in predicting success in donor egg IVF recipient treatment cycles. This study also suggests that the ectopic pregnancy incidence is unrelated to the air-bubble movement.