Embryo transfer completes the vitro fertilization (IVF) cycle. The number of embryos your doctor transfers depends on various factors including medical conditions, your age and guidelines provided by the American Society of Reproductive Medicine (ASRM).
In elective single-embryo transfer (eSET) your doctor transfers just one embryo instead of multiple embryos in order to reduce your likelihood of having twins, triplets or higher numbers of multiples, which poses a number of pregnancy and birth complications.
Who is a candidate for elective single-embryo transfer?
Elective single embryo transfer isn't for everyone. Some people need multiple embryos in order for one to implant. Therefore, eSET is reserved for women who are most likely to become pregnant. In general, your doctor may recommend on eSET if:
- You have more than one embryo of good quality (and are able to cryopreserve the remaining embryos)
- It is your first ART cycle or if you have already had a successful ART procedure
- You are using donor eggs
- You are younger than 35 years old (women 35-40 may be considered for eSET if they have good quality embryos at the blastocyst stage)
How is elective single-embryo transfer performed?
Your doctor performs a single embryo transfer the same way she would perform any other embryo transfer; the only difference with this procedure is she will transfer only one embryo to your uterus, rather than several.
When you go in for an embryo transfer, your doctor will:
- offer you a mild sedative.
- place the embryo in a drop of fluid, which is then drawn into a long, thin transfer catheter with a syringe on the end.
- insert a speculum into your vagina, and guide the catheter through your cervix.
- deposit the embryo into your uterus, using the ultrasound to find the appropriate spot.
If your doctor uses an abdominal ultrasound, she will usually request that you have a full bladder at the time of the procedure as this makes the uterus easier to see. The ultrasound will serve as your doctor’s guide as she performs the transfer.
After the procedure, you will rest on your back in a recovery room for an hour or two. Generally for about two weeks after your transfer, you will take a daily shot or pill of progesterone to help the embryo implant in the uterus and to prevent miscarriage.
Success rates and risks of elective single-embryo transfer?
For women who meet the criteria, and who generally have the best prognosis for pregnancy, pregnancy rates for eSET procedures are generally very good. The overall pregnancy rate for eSET is slightly lower than that of multiple embryo transfers, however, because women who are not ideal candidates also use the procedure.
The principle risk with eSET if you are not an ideal candidate is that you will not become pregnant and will need to endure the cost and inconvenience of multiple cycles to achieve pregnancy. However, many people prefer this risk to the potentially serious risks associated with carrying multiples, including preeclampsia, gestational diabetes, and preterm labor and delivery.
With eSET, if implantation is successful, you will have a greater chance of giving birth to a single baby without the additional complications and health concerns that are associated with carrying multiples.
Updated August 2014