A former gynaecologist who worked at the Rijnstate hospital in Arnhem used his own sperm to father at least 16 children in the 1970s and 80s, an investigation by the hospital has revealed.

The man, identified by the hospital as Alexander Schmoutziguer, has admitted he acted without telling the prospective parents and that he used his own sperm when no fresh donor sperm available. Frozen sperm was not used at the time. The investigation also showed that Schmoutziguer is a carrier of an unspecified hereditary disease.

The hospital has called on women who were treated at the hospital and their children to have their DNA tested.

“The actions of the doctor are unacceptable, also in light of the circumstances at the time. There is no doubt that the use of his own sperm in fertility treatments was in breach of the rules,” hospital board member Hans Schoo said.

New rules on sperm donation came into force in the Netherlands last year to prevent men from fathering hundreds of children by registering with multiple clinics.

A national register and a system of codes has been set up to enforce the limit of 12 families per donor.

Each donor is given a personal code and 12 maternal codes, which are used up every time a woman conceives using his sperm. Once all 12 codes have expired, the man is unable to donate sperm again.

The limit of 12 families was already written into Dutch law, but there was no mechanism to enforce it or the previous limit of 25 children because disclosing the identity of donors was seen as breaching their privacy.

A recent investigation by Nieuwsuur showed that non-enforcement of the limits has led to at least 85 mass donors, putting their offspring at greater risk of incest. Several fertility clinic doctors are also now known to be mass donors.