Why a Single Embryo Transfer May be Better
During your matching phase with Growing Generations, you will discuss whether your surrogate is open to carrying a singleton or a multiples pregnancy. The number of embryos that will be transferred into your surrogate will be decided the day of the embryo transfer after consulting with your IVF doctor. While most doctors prefer to transfer no more than two embryos, you should always be aware of how many are transferred with the knowledge that they could all take, resulting in multiple gestations.
What is elective single embryo transfer (eSET)?
When you begin to consider how many embryos you’d be comfortable transferring, you may believe that transferring more than one at a time will only help improve the odds of achieving pregnancy. You wouldn’t be alone in this thought process.
For many years, intended parents have opted to transfer multiple embryos. The logic was that IVF is an expensive process, and transferring multiple embryos would surely improve the odds of having at least one take and go on to result in a live birth. However, researchers at Duke University and the University of Colorado are turning that logic on its head and saying an elective single embryo transfer (eSET) may be the way to go.
In an eSET, only one embryo is chosen from the number of available fresh or frozen ones and placed in the uterus. Remaining embryos, if applicable, are frozen for later use.
The joint Duke and Colorado study is the first comprehensive comparison of the two methods, looking at outcomes for 30,000 patients who underwent IVF between 2012-2014. The largest study of its kind showed that the act of transferring multiple embryos often leads to multiple gestations. In the case of twins, triplets, or an even higher order of multiples, it is quite common for the babies to be born prematurely and encounter additional medical needs. It’s also common for multiple births to cause longer recovery times and pregnancy complications for the woman giving birth.
However, when doctors transferred a single embryo, there was no noticeable drop in the number of successful pregnancies. In the instances of eSET, the outcome was an improved probability of a full-term pregnancy and healthy live birth. In fact, researchers said that transferring just one embryo doubles the probability of a healthy live birth. The conclusion researchers came to was that it is in the best interest of the future fetus, the intended mom or surrogate, and the intended parents to transfer a single embryo at a time.
In addition, the study looked at IVF success rates in cases where doctors used both fresh and frozen embryos. They found that there was no clinical difference in the success rates. Given that the use of a frozen embryo rather than a fresh one is logistically much simpler and has become so common, researchers are suggesting that frozen embryo transfers are the wave of the future.
Of course, the plan you make with your doctor will be based on a number of contributing factors. Your doctor may still elect for, encourage, or allow multiple embryo transfers if that is what looks to be the most successful option.