Single embryo transfer nearly eliminates risk for multiples
Screening embryos in advance of an IVF transfer provides data for Dr. James Douglas to apply as he selects the embryos most likely to implant. Studies support the use of single embryo transfer with aneuploidy screening as one alternative to the traditional two embryo protocol.
For years, we would visually inspect the growth and development of fertilized eggs or embryos in the IVF lab. We could grade embryos and hypothesize how likely they were to implant. With this methodology, patients had a better chance at pregnancy with two transferred embryos, but they would also increase their risk for multiples (twins, triplets, etc.).
Today, more fertility centers, including IVF Plano, are moving toward genetic screening on Day 5 after fertilization, when the embryo has reached the blastocyst stage of development, with elective single embryo transfer, or eSET. We can schedule the transfer as a fresh cycle with rapid testing, or a frozen cycle in a subsequent month.
Aneuploidy screening examines an embryo’s genetic makeup
Preimplantation genetic screening, or aneuploidy screening, is a minimally invasive biopsy in which an embryologist removes a group of cells from the part of the embryo that will form the placenta—th trophectoderm–without disturbing the cells that will form the fetus. We refer to this as Day 5 trophectoderm biopsy and it is an alternative to Day 3 testing which is becoming less popular.
Once the results are returned to Dr. Douglas, we schedule a transfer at IVF Plano. Rather than run the risk of multiples with two embryos, prospective parents can confidently elect to transfer a single embryo after trophectoderm biopsy.
BEST Trial results confirm the effectiveness of eSET
A recent study presented at the American Congress of Obstetricians and Gynecologists* compared delivery rates between two groups of women under the age of 42 who were undergoing IVF.
One group had two untested embryos transferred either in the initial cycle or in a subsequent frozen cycle. This is considered the current standard of care and does not include embryo biopsy.
The other group had a single embryo transferred back to the uterus after aneuploidy screening; only embryos with a normal arrangement of chromosomes and no genetic abnormalities are selected for transfer to the uterus.
The results showed little difference in pregnancy and delivery rates between the two groups. What is significant, though, is that the practice of single embryo transfer essentially eliminates the possibility for multiple births.
Consider the risk for multiples
In this country, nearly half of all IVF births involve multiples. This puts the mother in a high-risk obstetrical category, and the baby at risk for preterm delivery, low birth weight and neonatal ICU stays.
You may be a good candidate for eSET, single embryo transfer
The Society for Assisted Reproductive Technology provides parameters for deciding if you are a good candidate for single embryo transfer. ASRM Fact Sheet
Women younger than 35 who are pursuing their first IVF treatment or who have already successfully completed an IVF cycle may wish to talk with a fertility specialist about the option.
Dr. Douglas is committed to helping his patients achieve a pregnancy without unnecessarily transferring multiple embryos. Contact IVF Plano for a consultation about elective single embryo transfer.