The single embryo transfer is also called e-SET procedure. This procedure is being increasingly recommended by fertility clinics offering IVF treatment. This is because multiple embryo transfers raise the risk of multiple pregnancies. This can be understood as a greater propensity towards having twins (multiple births), which isn't ideal due to the stress it induces upon the mother’s health. Multiple births are associated with greater mortality rates for the newborns too. Adopting single embryo transfer during implantation of the prepared embryo means that such issues are avoided.
Single Embryo Transfer Basics
SET technique is also called elective embryo transfer, since the IVF clinic staff elects the healthiest embryo for implantation. This technique is also called eSBT or blastocyst single embryo transfer, since many IVF technicians prefer to implant the embryo once it has attained the blastocyst stage of cellular development.
Single embryo transfer is usually done on an outpatient basis, as it is a small procedure wherein no incisions or sutures are required. It is done as a part of the IVF schedule that is explained to the IVF couple. Thus, the IVF female usually has a fair idea regarding the possible days on which she can be called for single embryo transfer.
Before the Procedure
On the schedule date, the IVF female is asked to change into the clinical gown. She might be tested for or inquired about the state of her menstrual flows, since IVF females can undergo single embryo transfer only when their uterus is capable of handling the implantation. The female should not be in the midst of a menstrual flow.
Usually, anesthesia is not needed since the procedure is not painful. However, if there is some history of hyper-anxiety in the patient, a mild sedative might be required. The IVF female is asked to lie down on the bed or a table. The bedding usually has a stirrup-like contraption at the end to help the patient spread her legs. This allows the attending specialist to access the uterus with minimal introspection.
During the Procedure
The IVF technician is already prepared with a series of embryos that are graded and marked according to their stage of development and overall health. At the time of implantation, the attending specialist chooses a graded embryo that has been pre-selected for implantation.
The fertility specialist equips himself with a sterile speculum. This speculum is directed into the vaginal opening of the patient. The speculum helps to penetrate the vagina without inducing any trauma and access the cervix. A solution is used to clean the cervix. The fertility specialist prepares a catheter that is equipped with the selected embryo at its tip. The catheter is guided along the speculum and inserted into the cervical canal, where it is directed towards the uterine tissue.
Carefully, the fertility technician unloads the tip of the catheter, ensuring that the fluid containing the embryo is emptied into the uterine cavity. Most IVF technicians use ultrasound for locating the spot of implanting the embryo. This is called ultrasound guided single-embryo transfer. The site of embryo deposition is usually in vicinity of the uterine fundus. In ultrasound-guided embryo transfers, the targeted site for embryo placement is often referred to as MIP point or Maximal Implantation Potential point.
After the Procedure
The catheter is slowly withdrawn and speculum retracted. The stirrups are eased. There is no down time for this procedure and it poses negligible health risks. The entire procedure usually takes about 20 minutes. The only post-treatment advice is a few hours of bed rest to ensure that the transferred embryo is not subject to physical trauma.