Wrong embryo implanted at Milan's San Raffaele Hospital, fertility lab suspended for 15 days

The incident

On 23 July 2026, at the assisted reproduction centre of Milan's San Raffaele Hospital, a cryopreserved embryo destined for one couple was implanted into a different woman. The error stemmed from an incorrect interpretation of the patient sequence in the daily schedule: two women were in the waiting room, but the one scheduled first was called second, and the embryo transfer was performed on the wrong patient. A witness biologist detected the mistake approximately eight minutes after completing the procedure. The hospital attributed the incident to human error and expressed "deep regret," stating that all procedures were activated immediately to ascertain the circumstances and protect those involved.

Immediate aftermath

Within 24 hours, the woman who received the wrong embryo was contacted and consented to an endometrial aspiration, a washing of the uterine cavity to minimise the risk of implantation of a biologically foreign fetus. The other couple was not immediately informed, to avoid emotional distress, and their correct embryo transfer was completed the following day. Adolfo Allegra, president of Cecos Italia, told ANSA that the hospital acted swiftly after detecting the error.

At San Raffaele fortunately they noticed it immediately after the procedure, and they immediately proceeded to do a washing of the uterine cavity to reduce to zero the possibility of implantation.

He added that approximately 12 days are needed to confirm whether pregnancy was avoided.

Regulatory response and inspections

The ATS of Milan, acting with the Lombardy Region and the National Transplant Center, suspended the embryology laboratory's activities for a minimum of 15 days from 6 August 2026, citing "non-conformities" found during inspections, one conducted jointly with the Ministry of Health. The last inspection took place on 4 August. The suspension may be extended until required corrective and preventive measures are completed. San Raffaele stated that internal reviews were initiated approximately two weeks before the public announcement, and that corrective measures have already been adopted, including reorganising the operating room entry so that the patient undergoing transfer is admitted before embryos are prepared.

A decade-long delay on safety technology

According to reporting by Repubblica, cited by Open, staff at the centre had been requesting an electronic witnessing system for ten years. The technology, already budgeted by the hospital in 2016, was never purchased. A formal request for technical specifications was submitted in December 2025, followed by organisational meetings that culminated in an informal approval on 21 July 2026, two days before the error occurred. The system functions as an automated safety barrier, emitting an acoustic alert when a biological sample does not match the correct patient, independently tracking sperm, oocytes, and embryos through every phase of the process.

Expert calls for mandatory tracking

Approximately 100,000 assisted reproduction cycles are performed annually in Italy. Estimates of tube-swap frequency vary: the hospital cited scientific literature placing it at 1 in 10,000 to 12,000 cycles, while Allegra referenced a figure of 1 in 15,000, noting that many cases go undetected. Ermanno Greco, president of the Società Italiana della Riproduzione, called the events rare but avoidable and urged making electronic tracking systems mandatory across all Italian fertility centres.

Even though these are very rare events, the tube swap that occurred during embryo transfer demands serious reflection. Today, thanks to modern technologies, it is practically impossible to encounter these errors.

The most notable previous incident occurred in 2013 at Rome's Pertini Hospital, where embryos from one couple were transferred into another woman. The pregnancy continued to term, producing twins and triggering a legal battle between the biological and gestational couples.