Egg or Embryo Freezing

Young women with cancer can also preserve their fertility by an IVF type procedure, retrieving individual eggs and freezing the eggs (or fertilizing them, in the case of married women for example, and freezing the embryos). With this approach, the young woman with cancer can undergo hormonal stimulation for several weeks after day one of her next menstrual cycle, to mature 10 to 15 follicles and the doctors can retrieve eggs by ultrasound-guided needle aspiration, just like with IVF. If they have a permanent partner, the eggs can be fertilized and the resultant embryos (rather than just eggs) frozen. Some may prefer this approach to having ovarian tissue frozen.

The problem with this approach of egg or embryo freezing for cancer patients is that it could delay the cancer treatment by 4 to 8 weeks, or even longer, and the patient's oncologist may not be willing to wait this long before initiating cancer treatment. Furthermore, like with any IVF procedure, the pregnancy rate per cycle is usually only 30% to 50%. So if she doesn't get pregnant from these frozen eggs or embryos (derived from just this one retrieval cycle) then she has no further options because her ovaries have already been destroyed by the cancer treatment. With frozen ovary tissue, she will have hundreds of thousands of eggs frozen and many more years of opportunities for pregnancies and children. That is why for most cancer cases, it is preferable and easier on the patient to perform ovarian tissue freezing to preserve their fertility rather than simple egg freezing or IVF with embryo freezing.

The other problem with eggs or embryo freezing for many infertility centers is that the conventional freezing technologies which most IVF labs use are not reliable. With most of these conventional freezing technologies, the vast majority of eggs are damaged and as many as half the embryos are destroyed. To use this method of fertility preservation, it is absolutely critical for the IVF lab to be very experienced with "vitrification."