Get access to over 1,300 articles and reader Q&As
Are success rates different for frozen transfers vs. fresh transfers?
– Anonymous
Most studies show higher success rates of frozen embryo transfers over fresh transfers. Much of the advantage is due to improved embryo selection with pre-implantation genetic testing and optimizing the uterine environment prior to an embryo transfer.
Increasing success rates translate to what we see in practice. In 2004, only about 8% of IVF cycles in the U.S. utilized frozen embryo transfer — that increased to over 40% by 2013!
Beyond success rates, frozen embryo transfers can help decrease complication rates with IVF. It allows for the use of a specific type of “trigger shot” at the end of your cycle that helps decrease the risk of developing ovarian hyperstimulation syndrome. There is also evidence showing that higher levels of hormones (estrogen and progesterone) at the end of an IVF cycle, leading into a fresh transfer, can contribute to a higher risk of preeclampsia, low birth weight, and preterm birth in pregnancy. However, frozen embryo transfer may also lead to preeclampsia in pregnancy as well.
This does not mean that fresh embryo transfers have been abandoned altogether, as not all studies have shown that frozen transfers are superior to fresh. A retrospective cohort analysis of fresh versus frozen embryo transfer, in patients electing not to do PGT, showed comparable pregnancy rates. However, the patients included in that study had a mean age of 32 years old where PGT may not provide as much of an advantage. The hormonal levels (estrogen and progesterone) reported prior to a fresh transfer in the study group were also in a range where the risk of OHSS was low and where we’d expect less of an effect on embryo transfer success rate. These parameters will not be true for all patients.
For the vast majority of patients, the approach of a frozen embryo transfer will be preferred owing to higher success rates and minimizing complications. How much higher the success rate would be over a fresh transfer depends significantly on age, the reason for fertility treatment, and the individual clinic’s success rates.
Community Guidelines
Log in