When the size of the leading follicles reaches 18 to 20 mm in average diameter and the estradiol hormone level is appropriately elevated, then it is time for the eggs to be “harvested”. The HCG injection (described in the previous section) will be administered in the evening usually between 7 PM and 11 PM. The egg retrieval will be scheduled 36 hours after the HCG injection. For instance, if the HCG is given on a Monday at 8:45 PM, then the egg retrieval will be performed on Wednesday at 8:45 AM.
The couple needs to be at PFC-LA at least 30 minutes prior to the scheduled time of Egg Retrieval (ER). The patient should not eat or drink anything after midnight, the night before the ER day.
The ER is performed under “general anesthesia” but without intubation. The patient will not feel any discomfort during the procedure and will wake up within 10 to 15 minutes of the end of the ER. Depending on the number of follicles present, the ER will usually last 10 to 30 minutes.
The procedure is performed under ultrasound guidance similar to the vaginal ultrasound examination that the patient has during follicular monitoring. A needle guide is attached to the ultrasound probe, a long needle is introduced through the guide, and under direct visualization each follicle is punctured and the fluid (along with the egg floating in it) is aspirated. The fluid is then immediately sent to the laboratory where the embryologists search for the eggs, isolate them and place them incubators. At the completion of the ER, the patient is taken to the recovery area where she will stay for about an hour. Pain medications might be administered at this time as needed. Some discomfort is expected for a few hours following ER and Tylenol can be taken by the patient at home as needed every 4 hours. Occasionally, some nausea might also occur which usually dissipates within a few hours.
After about an hour when the patient is fully awake and relatively pain-free, instructions are given by the recovery nurse and the patient is discharged home. The patient must be accompanied by someone who can drive them home and should not be left alone for the rest of the day.
While the patient is undergoing the ER, the partner is asked to provide us with a semen sample. The semen is then washed and prepared to inseminate the eggs 3-4 hours later. If ICSI is to be performed, the partner might be asked to give another semen sample if the first sample does not have an adequate number of viable sperm.
In cases where the male partner has to undergo the testicular biopsy (TESE or MESA) procedure, he will be taken to an adjacent operating room and the urologist will perform the needle biopsy under local anesthesia. This procedure will usually last 15-30 minutes and the patient will be discharged home with an ice pack placed over the testicles to prevent swelling. Read our IVF Procedures Blog for more information!
The risks of retrieval involve bleeding, infection and possible damage to adjacent organs. Intravenous anesthesia is usually used during retrievals.
Once the eggs are harvested and cleaned in the laboratory, they are incubated with sperm overnight to fertilize the eggs. Roughly 16 hours after insemination, the embryologist will check on the status of the fertilized eggs.
A fertilized egg is called an embryo. An embryo goes through stages of development until it is ready for transfer to the uterus. The following represent a schematic view of the growth of an embryo from the 2-cell stage to Blastocyst.
In these pictures actual photographs of an embryo is shown under magnification:
Three to five days following the Egg Retrieval the patient will have the Embryo Transfer (ET). During this time the fertilized eggs (embryos) have been allowed to grow and divide in the incubator. The patient would have also been started on Progesterone injections and/or suppositories the day of HCG injection to prepare the uterine lining for implantation.
The day before ET the patient will be contacted and given a specific time to come to PFC-LA for ET the next day. About 15 minutes before the transfer, the physician will meet the couple and discuss the number and quality of the embryos at hand. A decision will be made by the couple and their physician as to the number of embryos that will be transferred and the number to be frozen or discarded. The patient will then take a sedative pill if needed. The embryos will be separated into a separate dish and then transferred to the transfer catheter. Meanwhile the physician will prepare the patient for the ET. This is very similar to an artificial insemination procedure except that embryos are transferred to the uterus instead of sperm. A speculum is inserted in the vagina; the cervix is washed and cleansed. An ultrasound is used in most cases as guidance to the transfer. The embryologist will then deliver the catheter to the physician who introduces it through the cervical canal into the uterine cavity where the embryos are released. The embryologist will then check the catheter to make sure none of the embryos are in the catheter.
The whole procedure takes approximately 5 minutes. The patient will remain in a supine position for about an hour. She will then be discharged home. It is recommended that the patient rests at home for 1 or 2 days following the transfer.
A blood pregnancy test is done 10 days after the embryo transfer. Depending on the level of hCG hormone in the blood, another test might be requested in 2-4 days or an obstetrical ultrasound scheduled 2 weeks later to check on the health of the pregnancy. It is during this examination that we can determine the number of fetuses (i.e. twins or triplets).
We will follow our patients until the 10th week of gestation, after which, they will be discharged to their own obstetrician.
Most often, embryos are transferred 5 days after fertilization at the blastocyst stage.
IVF success is also dependent on the quality of the uterine lining. Both the thickness and texture are important parameters we check. The following figure shows an ideal thick and triple layered endometrial lining: