Fertilization and Embryo Development Step four:
Occasionally, the method of insemination may change from the original plan based upon the results of the semen analysis of the sperm collected on the day of the retrieval. The lab will perform a thorough sperm analysis on the retrieval day and will make recommendations to the physician as to which insemination method may work best for fertilization based upon the sperm results that day.
Day 1 — Day 1 is what the lab refers to as fertilization check day. Approximately hours after the insemination process takes place the embryologist will check to see if fertilization has occurred.
The embryologist is looking for evidence of 2 nuclei pn — one from the egg and one from the sperm. This is how the embryologist determines if normal fertilization has occurred. Any more or any less nuclei present and the embryo is considered abnormally fertilized and is not kept in culture.
Once normally fertilized, the embryos are placed back into the incubator and are not disturbed until day 3.
The embryos are grown in a specially designed culture dish which contains a small drop of culture medium overlaid with oil. This embryo culture medium contains the proteins, amino acids, and enzymes that mimic the fluid found in the fallopian tubes essential for embryo development.
One factor of many that contributes to successful embryo development is the constant maintenance of temperature and pH level of this embryo culture medium. The temperature and culture medium pH level is dependent upon the CO2 environment and the heat that is provided by the incubators.
Severe changes in the temperature and pH level of the culture medium can have potentially detrimental effects on the embryos. The embryologists are very protective of the embryos in the lab and this is the reason why the embryologists do not like to disturb the embryos too much and will not look at the embryos on a daily basis.
Once the embryologist releases the fertilization results, an IVF team nurse will provide an update to you on Day 1 regarding your fertilization results.Further division or "cleavage" takes place every hours, producing a 4- cell embryo on day 2, an 8-cell embryo on day 3, a morula or ball of, too many cells to count, on day 4, and a blastocyst on day 5.
Day 1 in the IVF Lab - Number of Eggs Fertilized Known. On Day 1 the eggs are checked for fertilization.
The embryologists look at the eggs in the morning and can see which have fertilized by the presence of 2 round spheres in the middle of the egg. Two-cell embryo (day ), usually starts at about 26 hours after sperm and eggs unite.
Four-cell embryo (day 2, approximately 48 hours after insemination).
During each mitotic division the embryo does not increase in size, and divides the existing cytoplasm. On day 5, the embryo develops into a blastocyst.
At this stage, it is usually possible to grade the inner cell mass (ICM), the fetal component, and the trophectoderm cells (TE), the placental component, of the embryo.
The embryologist make notes about what has occurred since the previous day and adds them into the patient’s electronic record. The goal is to see the slow and steady development of a 4-cell embryo on the second day of development into an 8-cell embryo on the third day. About 3 days after conception: The zygote now consists of about 16 cells and is called a morula (a.k.a.
pre-embryo). It has normally reached or exited the fallopian tube and entered the uterus. It has normally reached or exited the fallopian tube and entered the uterus.