1. Follicular Recruitment and Monitoring (Pre-Retrieval)

Eggs develop within a small sac of fluid in the ovary, known as a follicle. Not all follicles will produce eggs that could be harvested during retrieval or that are of adequate maturity to be used for fertilization.

2. Egg Retrieval (Day 0)

All visible follicles are aspirated by the physician, and the collected fluid is handed to the embryologist who will check for the presence of eggs. Typically, the larger follicles (>16mm) will produce mature eggs, but there’s no guarantee that they will release from the follicle. In addition, some follicles may simply be empty.

3. Fertilization Check (Day 1)

On the day following your egg retrieval, the embryologist will check for normal fertilization by looking for two clear nuclei that form inside the egg (one maternal and one paternal). Each of these nuclei contains half of the embryo’s chromosomes.

4. Cleavage Check (Day 3)

By day 3, healthy embryos should have reached the 6-8-celled stage and should have little or no fragmentation. Embryos that have not reached the 6-celled stage by day 3 or that are highly fragmented will most likely not continue to develop. It’s still too early to know how many total viable embryos you will have for transfer, biopsy, and/or freezing as they need a few more days of undisturbed growth.

5. Blastocyst Check (Day 5)

Five days following your egg retrieval, the embryologist will check your embryos to see if they advanced into the final stage of in vitro development, known as the blastocyst stage.

On day 5, most embryos are not yet ready for biopsy or freezing. They usually require one more day of growth. In these cases, the embryologist will only call you on day 6 with a final update.

6. Final Blastocyst Check (Day 6)

By day 6, all viable embryos should have reached the blastocyst stage and all others will have arrested. These viable embryos will undergo genetic testing and/or freezing, as per your particular treatment plan.