Abstract
During an in vitro fertilization treatment cycle, having embryos retained in the catheter after embryo transfer is a relatively uncommon and frustrating event. The reported incidence of retained embryos varies between 1% and 8%. It can be difficult to explain this unwanted event to patients. We wished to determine the incidence and the effect on pregnancy rates of having embryos retained in the transfer catheter, followed by immediate completion of transfer.
We performed a retrospective chart review of all IVF cycles with embryos retained in the transfer catheter, followed by repeat transfer, between October 2009 and March 2012. We reviewed IVF cycles with or without ICSI, and included fresh and frozen embryo transfer cycles. All embryos were transferred on the third day after oocyte retrieval. Transabdominal ultrasound was used for guidance during the embryo transfer.
A total of 49 IVF treatment cycles with retained embryos that required re-transfer were identified. This represented 7.5% (49/652) of all IVF cycles with embryo transfer during that period. The clinical pregnancy rate in the repeat transfer group was 30.6% (15/49). The clinical pregnancy rate in all cycles in the same time period was 34.8% (227/652). These rates were not significantly different (P=0.521).
Having to re-transfer embryos retained in the transfer catheter does not have any significant effect on clinical pregnancy rates during IVF treatment cycles.