Is it permissible to freeze embryos in the IVF process to avoid re-stimulating the ovaries if the procedure fails?

Scholars have differed on the ruling regarding in-vitro fertilization (IVF) between spouses. Sheikh Bakr Abu Zayd, in his research "Modern Reproductive Methods in Medicine and Their Juristic Rulings," mentioned that there are risks and prohibitions surrounding this procedure, including the persistence of frozen embryos in the laboratory after a successful operation. This could lead to their transfer to someone other than their rightful parents, which is absolutely forbidden, or their destruction, which is unlikely for doctors to do. The issue is not only about preventing the mixing of ova but also about disposing of excess ova and ensuring they are not used for another woman. Therefore, the difference among scholars on this matter stems from the degree of assurance that the fertilized ova will remain in embryo banks without mixing, tampering, or unauthorized use by others, which could lead a person into sin or compromise their lineage. If these prohibitions can be safeguarded against, then there is no harm in freezing embryos.