Fertilization and Embryo Development
IVF - How In Vitro Fertilization Takes Place
Although IVF treatment consists of a long and complex series of procedures, it is the stage that takes place in our laboratory, where sperm and egg finally come together, that defines the process. Literally meaning "fertilization in glass," in vitro fertilization, or IVF, is how our Fort Lauderdale and Southeast Florida area fertility specialists are able to help patients overcome numerous types of fertility problems.
After ovulation induction and egg retrieval, the collected eggs are sent to our Florida fertility clinic's lab, where they are examined and prepared for in vitro fertilization. The semen is collected on the same day as the egg retrieval procedure and is also examined in the laboratory. Sperm are washed and sorted to ensure that only the healthiest, most motile sperm are combined with the eggs, maximizing the chances of successful fertilization.
Once both sperm and eggs have been properly prepared, each egg is combined with a sample of selected sperm in dish containing a special IVF culture that is designed to support and nurture the embryo through the first few days of development. Each dish is placed inside an incubator while in vitro fertilization takes place. After 18 hours, the dishes are retrieved for examination. Eggs that have been successfully fertilized can be identified at this stage and will be returned to the incubator. Eggs that remain unfertilized after the initial 18 hours are unlikely to become fertilized and are therefore discarded.
Once fertilization takes place, cell division begins, just as it would under natural conditions. The embryos will continue to be observed at regular intervals until at least three days after in vitro fertilization. Embryologists will monitor the rate of growth and look for any signs of abnormal development. Potential anomalies include a slow rate of cell division, failure to develop, multinucleation (when cells have two or more nuclei, instead of only one), and fragmentation (when small particles of cytoplasm become trapped inside the zona pellucida). Minor fragmentation is generally not cause for concern, although healthy embryos without any fragmentation will be selected if they are available. The transferability of embryos that develop slowly will depend on the degree of deviation from the norm as well as other factors. Multinuclear embryos and those that arrest, or fail to develop, do not qualify for transfer and will be discarded.
Most IVF practices perform embryo transfer after three days of development. At this stage, the embryos ideally have between six and nine cells and the strongest, healthiest specimens can be easily identified. For some in vitro fertilization patients, however, transfer at five days, when the embryos have reached the blastocyst stage, is a preferable option. The main benefit of blastocyst transfer is that at five days it is easier to determine which embryo(s) will most likely implant and develop, so fewer embryos need to be transferred, resulting in a lower risk of a multiple pregnancy. However, in some cases, embryos fail to develop to the blastocyst stage in the IVF culture. The best option for each patient is decided on a case-by-case basis.
While the majority of IVF embryos are formed and developed in a laboratory-created culture medium specially designed for in vitro fertilization, it is also possible to use a sample of endometrial cells to support the developing embryo. For some women, this appears to increase the chances of successful implantation after embryo transfer.
Contact Us in Fort Lauderdale and throughout Southeast Florida
If you think you may be a candidate for in vitro fertilization (IVF), please contact our Southeast Florida practice, located in the Fort Lauderdale area. We will be happy to help you schedule a consultation.