Congratulations – you’ve completed your egg retrieval procedure and are resting comfortably back at your hotel. Now that you’ve completed your egg donor responsibilities, you’re wondering what happens next for your hopeful parents after egg retrieval.
The steps following your egg retrieval procedure are coordinated by highly skilled technicians, called embryologists, who use state-of-the-art medical technology to provide your hopeful parents with the very best chance of success in their family-building journey.
Embryologists evaluate development of the egg and developing embryo at certain moments post-retrieval in order to examine quality, growth, and development.
Day-0 – Egg Retrieval Day/Insemination Day
On egg retrieval day, your physician will aspirate the follicular fluid and cell material from each of your growing follicles. In the adjoining embryology lab next to the retrieval procedure room, the eggs are isolated from the follicular fluid and mature eggs are placed in dishes with special culture media. This media, together with a combination of other environmental factors carefully controlled in the lab setting (such as pH, light, temperature, air filtration, humidity, and gas concentrations to carefully control nitrogen, carbon dioxide, and oxygen), mimic the conditions in a woman’s body and optimize the likelihood of success.
In addition to the egg retrieval, the lab will obtain a sperm sample from the recipient father(s) or sperm donor on egg retrieval day (or in advance of egg retrieval day). The embryologist will process the sperm sample by “washing” it to remove seminal fluids and ready sperm for fertilization of mature eggs.
On the afternoon of egg retrieval (approximately 4-6 hours following your egg retrieval procedure), the eggs you’ve donated will be fertilized. This is done in one of two ways – traditionally through a process of standard insemination, where a sample of washed sperm cells are added to each dish containing an egg, or through a specialized technique called intracytoplasmic sperm injection (ICSI), where an embryologist injects a single sperm into the cytoplasm of each mature egg using a specialized needle. No matter how fertilization takes place, the eggs and sperm then incubate overnight.
Day-1 – Fertilization Check
On the morning following your egg retrieval procedure (approximately 16-18 hours following insemination or ICSI), an embryologist will assess each egg to identify those that have fertilized, indicated by visualizing two pronuclei under the microscope (that is, a nucleus from the egg and another from the sperm). These fertilized eggs, called zygotes, will be stored in petri dishes with specially formulated culture medium to support cell growth.
Day-3 – Cleavage Check
On day-3 following your egg retrieval procedure, an embryologist will evaluate the growing embryos to identify embryos reaching cleavage stage, indicated by visualizing embryos having developed into 6-8 cells. In addition, the embryologist will also look at the embryo’s appearance to evaluate the embryo’s symmetry and cell fragmentation, assigning a grade to each embryo.
Day-5 – Blastocyst Check
On day-5 (or day-6) following your egg retrieval procedure, an embryologist will evaluate embryos that have developed to the blastocyst stage. At this stage of development, an embryo begins to differentiate into two separate group of cells – an inner cell mass, which gives rise to all the tissues of the fetus, and the outer cell layer called the trophectoderm, which gives rise to the tissues of the placenta.
Embryo Genetic Testing, Cryopreservation, and Transfer
At day-5 (or day-6) following your egg retrieval procedure, one of two things may take place. Your hopeful parents may choose to undergo their embryo transfer (called a “fresh” embryo transfer), or alternatively, they may elect to have their embryos undergo genetic biopsy and be cryopreserved for future transfer (later called a “frozen” embryo transfer).
Embryo Biopsy For Genetic Screening
Embryo genetic testing increases the chance of pregnancy by identifying the healthiest embryos, and there are currently two different types of genetic testing available: pre-implantation genetic disorder (PGD), also known as pre-implantation genetic testing for monogenic/single gene diseases (PGT-M), or pre-implantation genetic screening (PGS) testing, now being recognized as pre-implantation genetic testing for aneuploidy (PGT-A). Both forms of testing require the biopsy of a small number of cells from the trophectoderm of the embryo on day-5 (or day-6) following egg retrieval, with the biopsy sent to a special laboratory to test for genetic abnormalities. Meanwhile, embryos are frozen through a special freezing process called vitrification in order to await genetic test results (7-10 days).
Using the PGD/PGT-M testing process, the presence of a single gene defect may be identified, such as is found with diseases such as cystic fibrosis, beta thalassemia, or spinal muscular atrophy. PGD/PGT-M offers a life-altering opportunity for hopeful parents who are carriers for certain heritable genetic disorders to identify affected embryos, unaffected embryos, and those embryos carrying a disease in question.
As compared to PGD/PGT-M, which only examines an embryo for a specific single gene defect, the PGS/PGT-A testing process is more extensive. An embryo is evaluated for the correct number of chromosomes (identifying healthy embryos free from aneuploidies), thus reducing the risk of transferring abnormal embryos that might result in miscarriage or birth defect.
Embryo Transfer Day
On the day of your hopeful couple’s embryo transfer, their physician will perform the embryo transfer using ultrasound guidance to introduce a catheter into the uterus (or their surrogate). The embryo is released through the catheter, and your hopeful recipient will then be monitored closely for several weeks.
Initial Pregnancy Testing
Your hopeful parents will undergo pregnancy testing approximately nine days following embryo transfer, using a blood hormone test to determine the quantitative amount of human chorionic gonadotropin (hCG) hormone in the blood. If the hCG blood test is positive, then your hopeful parents will undergo testing again 48 hours later to evaluate the increase in hCG hormone in the blood. Thereafter, if levels appear appropriate, your hopeful parents will schedule their first transvaginal ultrasound approximately four or five weeks following embryo transfer to look for a fetal heartbeat.
Each and every egg donation cycle is unique, but the outline of events above should give you a good idea of what happens for your hopeful parents following your egg retrieval procedure. If you have further questions, contact our office.