Elective SET is defined as the transfer of a single embryo, whether it is at the cleavage stage (2-3 days after fertilization) or at the blastocyst stage (5-6 days after fertilization). The primary rationale for performing eSET is to reduce the multiple pregnancy rate associated with IVF. Approximately 30% of IVF pregnancies result in a twin pregnancy and another 3-4% result in a triplet or a higher order (four or more implanted embryos) pregnancy in the United States.
Multiple pregnancies can significantly increase the risks and complications to both mother and babies. In general, mothers have a higher risk for hypertension, gestational diabetes, preeclampsia, eclampsia, premature labor and delivery. Premature delivery can lead to long-term lung and gastrointestinal problems, cerebral palsy and even neonatal death.
When eSET is used in conjunction with PGD, it provides for unparalleled success rates for delivering one healthy child.
In general, pregnancy rates are highest when the highest quality embryo is transferred. The embryo quality is a function of the woman age and ovarian reserve.
Some of the patients who would benefit from eSET include: