A European study of nearly 3000 patients confirmed the safety of freezing using the vitrification method and transferring cryopreserved embryos. The study of over 1000 live births from frozen embryo transfers and nearly 2000 live births from fresh embryo transfers revealed no differences in outcomes for the offspring. The study particularly focused on major congenital malformations and no difference seen between embryos transferred on a fresh cycle come paired with those that were transferred after vitrification.
In terms of obstetrical care outcomes, babies born from embryos that were vitrified actually showed a lower small for gestational age rate and in a higher birthweight. Preterm births and perinatal complications were comparable between the two groups. Previous studies showed that our older method of cryopreservation was safe. This study confirmed that the newer method of freezing embryos, vitrification, is safe as well. Previous studies have shown babies born after cryopreservation have a lower risk of major malformation compared with babies born without IVF. These studies confirm that babies born from cryopreserved embryos are as healthy if not more healthy than babies conceived naturally.
For more information see the journal, Human Reproduction: May 2016