As mentioned above, in most cases, more than one embryo is transferred to the uterus to increase the chance of pregnancy. This depends on several factors such as the results of medical examinations, the couple's readiness for the possibility of having multiple children, the percentage of multiple pregnancies in the medical center, the mother's age, etc.
In most cases, a maximum of three embryos are transferred to the uterus; however, if the mother is older – for example, over 53 years – sometimes, transferring more than three embryos is permitted.