Transfer of IVF-contaminated blastocysts with removal of the zona pellucida resulted in live births

Purpose: Bacterial contamination may cause loss or damage to cultured oocytes or embryos, resulting in cancelation or delaying of a fresh embryo transfer. While live births have been reported following the transfer of embryos contaminated with yeast, very little information is available on how to handle embryos with bacterial contamination. We report two cases of successful pregnancy in patients with bacterial contamination of embryo culture dishes. Methods: We retrospectively reviewed 878 oocyte retrievals performed between January 2011 and December 2014. Bacterial contamination was recorded in two split IVF/ICSI cases, where contamination occurred in embryo culture drops containing embryos from conventional insemination but not from ICSI on day 3. Results: To minimize the adverse effects of bacterial contamination on transfer outcomes, we removed the zona pellucida of contaminated frozen blastocysts and successfully obtained clinical pregnancies following transfer of zona-free blastocysts that were previously contaminated during IVF culture. Conclusions: Removal of the zona pellucida is an appropriate approach to handle blastocysts contaminated with bacteria during in vitro culture.