In IVF treatment, embryos are traditionally transferred in the uterus three days after fertilization. Due to improvements in laboratory techniques, this is now also possible after five days. It was assumed that this increases the chance of a successful pregnancy.
A study by Radboud university medical center and Amsterdam UMC shows that the day of transfer does not influence the success rate of the IVF trajectory. One out of thirty children in the Netherlands is conceived via in vitro fertilization, or IVF for short. In this procedure, egg cells are fertilized outside the body and grown in the laboratory for several days.
One or more embryos are then transferred back in the uterus and the rest is frozen. Traditionally, the laboratory phase lasts three days. Due to technical improvements, embryo transfer is now also possible after five days.
The idea is that only viable embryos remain after five days, which increases the chance of a successful pregnancy. However, this leaves fewer embryos in the freezer. Previous research has shown that the chance of success after the first transfer is indeed higher when this takes place on day five than on day three.
But these studies did not evaluate the results of the entire IVF trajectory, including any subsequent transfer of frozen embryos. Research by Radboud university medical center, carried out in collaboration with Amsterdam UMC, changes this. The same number of pregnancies The study was conducted in 21 Dutch IVF centers among more th.