In Vitro Fertilization (IVF): Traditional IVF
Embryo Development Cycle "inside the IVF Lab"
Note: Our lab passed FDA inspection 2-28-08, CAP inspection 8/7/2009.
See "What Makes our IVF Lab Special?
Once your retrieval is completed, other than taking your prescribed medications, there is nothing that you can do to positively affect your outcome. The best thing you can do to produce a healthy pregnancy is to rest and leave the embryo culture to us. Your embryologist will call you with all important information pertaining to your embryo development. At the completion of your cycle you will receive a letter summarizing the details of your cycle. In attempts to alleviate your anxiety, we have outlined a day-by-day description of what we hope to see as your embryos develop.
Day 0: Retrieval and Sperm Collection
Following your retrieval your physician will tell you how many oocytes (eggs) were recovered. Not all of the oocytes retrieved will be suitable for ICSI (intra-cytoplasmic sperm injection) or for conventional IVF. ONLY those oocytes that are mature will fertilize. The rule of thumb to remember, is that anything above 50% is good.
Day 1: 18 hrs. Following Retrieval
Woo Hoo! Normal Fertilization has occurred. Fertilization is noted by the presence of 2 pronuclei. This represents the chromosomal material from both you and your husband. Unfortunately at this stage, fertilization is all that we can tell. We can not accurately predict how the embryos will develop. Once again, a fertilization percentage of over 50% of your mature oocytes is good.
Day 2: 48hrs. Following Retrieval
Each day of development there is an ideal cellular number that your embryos should obtain. At the first replication, hopefully your embryos will be between 2 to 4 cells. Anywhere is that range is perfectly normal.
Day 3: 72 hrs. Following Retrieval; Potential Transfer Day
Most embryo transfers occur on D3 of development. Ideally, your embryos should be approximately 8 cells. More importantly than being 8 cells, it is critical that all cells within the embryos have replicated from the previous day… ie, if your embryos were 2 cells yesterday, they should be at least 4 cells today. Assisted hatching is a technique utilized to produce a small hole within the embryo's zona pellucida (cell membrane). Hatching is done at the physician's discretion and is usually reserved for patients that have a mature age, previous failure, or poor embryo quality. If you are a patient undergoing PGD, (preimplantation genetic diagnosis) the embryo biopsy would be performed today.
Day 4: Extended Culture
The Morula stage is a very non-descript stage within embryo development. Cells within the embryo lose all configurations and adopt a "blob like" appearance. This occurs in order to allow for rapid cell division. Morula is consistent with approximately 25-50 cells.
Day 5: Blastocyst; Potential Transfer Day
Blastulation occurs immediately prior to hatching and implantation. It can begin to occur as early as late on D4 to early on D7. By the time your embryos have progressed to the blast stage, they will have differentiated into what will become your fetus and into what will form accessory pregnancy material. By transferring on this later stage of development, we can more accurately pick the best embryos which will lead to a high pregnancy potential. However, the downfall for a blastocyst transfer is that the embryos will remain in a synthetic uterus for 2 more days. The best conditions we can create in the laboratory aren't nearly as good as in your uterus. Therefore blastocyst transfer is reserved only for patients that have superior embryo quality. It is our recommendation that if your embryos are not perfect on Day3, you do not consider the option of doing a blastocyst transfer. Marginal embryos have a higher pregnancy potential when replaced on Day 3.
Day 6: Hatching Blastocyst
This is the final day of your cycle. We will give your embryos every opportunity to develop, but unfortunately, if they are not showing blastulation by today, the possibility that they will is very slim. All embryos that do not blastulate will be discarded.
Cryopreservation
In order to maximize your embryos not used for transfer, we will freeze embryos on D3, D5 and D6. The day of cryopreservation is solely determined by embryo quality. Once frozen, your embryos will indefinitely remain at the stage in which they were at the time of cryopreservation. Consider frozen embryos a bonus to your fresh cycle and do not plan your fresh transfer on the fact that you have frozen embryos. You can expect to lose a portion of your embryos as they go through the freeze and thaw process.