IVF
Single Embryo Transfers
Transvaginal egg retrieval
The goal of an IVF cycle is to achieve a healthy pregnancy. Although many couples perceive multiples as the ideal outcome in an IVF cycle, at Dallas IVF, we do not. Our goal is, and always has been, to achieve a singleton pregnancy with each cycle, with twins as an acceptable risk. With the advent of day 5 blastocyst transfers several years ago, we are now able to transfer fewer embryos, yet achieve high pregnancy rates with a reduced multiple rate. Day 5 blastocyst transfers have higher implantation rates than 8-cell, day 3 embryos. By culturing embryos for an additional two days, we are able to select out ‘the best’ embryos. This is not to say that every program that performs day 5 transfers has excellent pregnancy rates, nor, does it mean that those programs that perform only day 3 transfers are unable to achieve excellent rates with a limited number of embryos transferred.
The American Society for Reproductive Medicine (ASRM) has published guidelines on how many embryos to transfer in different age groups. Practices are encouraged to limit the number of embryos transferred to avoid the risk of multiples, especially high order multiples. At Dallas IVF, we encourage good candidates (young women and donor egg recipients) with excellent quality embryos to have a single embryo transferred. Although encouraged, couples can still decline single embryo transfer. We make a strong effort, when possible, to follow the ASRM guidelines on the number of embryos to transfer. Many other programs do not follow these guidelines. These programs transfer excess numbers of embryos in an attempt to compensate for lower pregnancy rates. However, this may lead to the danger of high order multiples. We at Dallas IVF have always been proud of our pregnancy rates and our exceptionally low triplet rates.
At Dallas IVF, we have demonstrated that good candidates, who elect to have single embryo transfers, achieve, on average, a 70 percent pregnancy rate. Although women who are good candidates and decide against single embryo transfers have an 80 percent pregnancy rate, they often have a 60-80% twin rate. By accepting a 10 percent reduced rate of achieving a pregnancy, a couple basically can avoid the risks of multiples. Some women electing for single embryo transfer may still develop twins as the embryo may split into two embryos after the transfer. Dallas IVF has a 1 percent split rate in our blastocyst transfers. Meaning, if a patient conceives following a single embryo transfer, there is a 1 percent chance the embryo will split, leading to an identical set of twins.
