Wrong embryos implanted in fertility mix-up
Italy's health ministry said it's launching an investigation into the error, which was only discovered when the woman was three months pregnant.
The mistake happened on 4 December, when four different couples were receiving treatment at a specialist fertility unit at the Sandro Pertini Hospital in Rome, La Stampa newspaper reported on Sunday.
It is not clear whether the mistake led to any of the other women becoming pregnant with the wrong baby.
Health Minister Beatrice Lorenzin said investigators would look at whether the hospital had "respected all the legal procedures" and expressed concern she had only learnt about the mistake through press reports.
"The national standards on assisted fertilisation, 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.
The local health authority in Rome said it