The mistake happened on December 4, 2013, when four different couples were receiving treatment at a specialist fertility unit at the Sandro Pertini Hospital in Rome.
The embryos were mixed-up, so it is impossible to establish the belonging of the embryos. At least one embryo transfer took place with making the woman pregnant with another’s embryo.
The fact was adjudged only when the woman was three months pregnant. The doctors became aware only because genetic incompatibility between the parents and the embryos
Italy's health ministry said it was launching an investigation into the mix-up.
Health Minister Beatrice Lorenzin said Sunday investigators would look at whether the hospital had "respected all the legal procedures" and expressed concern that she had only learnt about the mistake through press reports.
"The national standards on assisted fertilization, which are based on European directives, are very rigorous, and if applied correctly, guarantee the traceability of all biological material used in the reproduction process," she said.
All embryo implantations at the clinic are stopped until further notice.
La Stampa, 14 April 20142014.04.13