Around two or three days before the embryo transfer, the doctor will choose the best eggs to transfer to the womb.
There are many processes available to aid selection, though non-invasive methods such as metabolomic profiling are becoming favoured. Metabolomic profiling is the process of selecting the most beneficial eggs based on a number of different factors. This limits the need for invasive procedures and increases the number of useful eggs.
These eggs will then be fertilized in a lab and left to culture for one to two days. If many good quality embryos develop, the ones that are not going to be transferred can be frozen.
The process of an embryo transfer
The embryo transfer process is similar to the process for a pap smear. The doctor will insert a speculum into the woman’s vagina to keep the vaginal walls open.
Using ultrasound for accuracy, the doctor will then pass a catheter through the cervix and into the womb. From there, the embryos are passed through the tube and into the womb.
The process is usually pain free and rarely requires any sedatives. Some women may feel discomfort as a result of having the speculum inserted or from having a full bladder, which is required for ultrasound. The process is short, and the bladder can be emptied immediately after.
After the embryo transfer
The doctor may recommend lots of rest following the procedure. This may help ensure that the embryo sticks to the wall of the womb, which may result in pregnancy.
A follow-up appointment two weeks later to check if the embryo has implanted will show if the transfer was successful.
After the procedure, women may experience some cramping, bloating, and vaginal discharge.
Types of embryo transfer
In order to extract and fertilize the eggs during IVF, doctors generally follow the same process every time. Once fertilization has occurred, there are a few different options available for embryo transfer:
Fresh embryo transfer: Once eggs have been fertilized, they are cultured for one to two days. The best eggs are chosen to transfer directly to the woman’s uterus.
Frozen embryo transfer: Any healthy embryos that were not used in the first transfer can be frozen and stored for future use. These can be thawed and transferred to the uterus.
Blastocyst embryo transfer: If many healthy embryos develop after the fertilization, doctors may recommend that the woman wait to see if the embryos develop into blastocysts. According to a study in the Indian Journal of Clinical Practice, blastocyst embryo transfer has a higher success rate than the standard embryo transfer on day 3.