What happens if you use your eggs or embryos that you’ve frozen through Ovally or elsewhere later on? In the case of frozen eggs, the eggs would be thawed and then fertilized with your partner’s or a donor’s sperm. The resulting embryo(s) would develop in the lab until they’d be ready to be implanted in the uterus (typically on day 5 of development). Then one embryo (in rare cases more than one) would be implanted through a catheter inserted all the way into the uterus, which sounds really uncomfortable, but is usually painless. Ideally the embryo would implant there, and a few days later a blood test would confirm a pregnancy. In the case of frozen embryos, only the embryo implantation or “embryo transfer” would have to take place, as the eggs would already have been fertilized and developed.
For anybody who has frozen their eggs or embryos abroad, the woman hoping to get pregnant would only have to return for about 2 days for the embryo transfer and a subsequent checkup. If she has frozen eggs instead of embryos, her partner or sperm donor would have to add their contribution a few days prior (or send a frozen sample), so the clinic’s lab could start fertilizing the thawed eggs and nurturing the embryos for a few days to get ready for implantation.
Depending on the circumstances that lead you to complete IVF with the frozen eggs or embryos, there might be additional treatments before, during, and after the embryo transfer. For example, there are different protocols to prepare the uterus for the implantation depending on the results of hormonal blood tests and the likelihood that you ovulate naturally. One option is a “natural” cycle without any additional hormones, where the embryo is thawed and implanted a few days after natural ovulation (e.g., 5 days after ovulation if it had matured to the 5-day-old blastocyst stage before freezing).
Alternatively, you may be prescribed some hormones to improve the chances ovulation and thicken the uterine lining where the embryo needs to implant in order to make it as receptive as possible. For instance, this could include taking a form of estrogen at the beginning of your cycle until ovulation to thicken the uterine lining, followed by some doses of progesterone to make it as receptive as possible prior to implantation.
These are only a few examples of additional treatments, which would be determined by your doctor based on your specific condition. All treatments could be completed in Spain, or any pre-transfer treatment could happen wherever you are located at the time if you have frozen eggs or embryos in Spain. Frozen eggs or embryos can also be transferred between fertility clinics, provided certain legal and medical regulations are met.