Cryopreservation of embryos by vitrification at a private sector reproductive medicine facility in Karachi

To assess the survival of freezing cleaved human embryos through vitrification. The prospective study was conducted at the Karachi-based Sindh Institute of Reproductive Medicine between June 2008 and June 2009. The cryopreservation of embryos being a new technology in Pakistan, only 19 couples, picked through convenience sampling, comprised the study population. The couples were treated for infertility by in virto fertilisation (IVF) or intracytoplasmic sperm injection (ICSI); 125 surplus embryos were vitrified. Subsequently, 15 embryos were thawed, and transferred in a controlled cycle. SPSS version 11 was used for statistical analysis. After the surplus embryos were vitrified and subsequently thawed and transferred, the survival of the embryos was assessed by the number of blastomeres that were intact. The overall embryo survival rate was (14/15) 93.33%. Vitrification is a simple procedure that requires less time and is likely to become safer and more cost-effective with time. Survival rate after thawing and preserving is high, but comparative success rates in terms of pregnancy and taking-home-baby rates are yet to be established in Pakistan.