Embryo transfer is the final and probably the most important step of the in vitro fertilization procedure. The embryos are transferred in the woman’s uterus hoping that she’ll get pregnant. This stage follows the egg retrieval and can be performed after 2-3 days after that depending on the woman’s age and the number of embryos.
The number of embryos advisable to be transferred is between 2 and 4 because it is obvious that the chance of getting pregnant is bigger. However it should be also taken into consideration the fact that all the embryos could be implanted and a risk of multiple pregnancies can appear. In that case the woman’s health as well as the baby’s health can be severely affected. The factors that indicate the number of embryos that should be transferred are: the patient’s age, the number of healthy embryos formed after egg retrieval and the risk of multiple pregnancies.
The embryo transfer can be splitted in two categories:
-the transfer of embryos 3 days after the egg retrieval.
– blastocyst transfer : it takes place after 5 days of culturing when the embryos reach the blastocyst stage. It is easier to select a healthy embryo at this stage.
The embryo transfer procedure is totally painless, so the patient doesn’t need to receive an anesthesia during the process. Usually is better for the patient to have a full bladder because this way the uterus is more visible by means of an abdominal sonogram.
The vaginal canal and the cervix are cleaned of any cervical mucus that might interfere in the process of placing the embryos in the uterus. After selecting the appropriate number of healthy embryos to be transferred, these are put in a fluid and kept in a catheter. The catheter is passed afterwards through the cervix guided by the sonogram so that the doctor could see the right spot in the uterus where to deposit the embryos from the catheter. Usually the best spot to place the embryos is the top of the uterus.
After the embryo transfer the patient might feel a slight cramping. Sometimes (very rare) when transferring the embryos through the cervix they might be misplaced into the fallopian tubes.
In addition to this small infection or bleeding can appear after this procedure.
After the embryo transfer the patient remains lied down for a couple of hours and afterwards she can go home. It is advisable to rest the next 2 days and only after that period the patient can resume her normal activities.
The doctor will decide what additional medications should be given after the transfer. The most common are the injection of hCG or progesterone.
In 12-14 days after the embryo transfer a blood test will be performed to find out if the conception took place.
In most of the cases embryos remain after the in vitro fertilization procedure. The couple has to decide what to do with them. There are a couple of choices like:
-embryo donation- they can help other infertile couples who are trying to conceive
-embryo cryopreservation- involves freezing the remaining embryos for future use by the couple in their future treatment .