Information about donor treatments

Change in the law

On 1 April 2025, the Artificial Fertilisation Donor Data Act (Wet donorgegevens kunstmatige bevruchting) was amended. The Donor Data Board for Artificial Fertilisation (Stichting donorgegevens kunstmatige bevruchting, Sdkb) is now called the Donor Data Board for Artificial Fertilisation (College donorgegevens kunstmatige bevruchting, CDKB). The most important change is that the CDKB can now centrally monitor that the sperm of one donor is used for a maximum of 12 women. This helps prevent large networks of genetic relatives from forming. This was not possible before, as there was no legal basis for comparing the donor data registered by the clinics.

A new way of registering

In recent months, a donor code has been linked to every unique donor already registered. All registered women have been given a mother code linked to the donor code of the donor whose gametes were used in their treatment. A maximum of 12 mother codes is available per donor. Thanks to this new way of registering, the CDKB and the clinics have gained more insight into the number of offspring per donor conceived through clinics in the past.

Professional guideline

From 2004 to 2018, clinics followed the professional guideline of a maximum of 25 offspring per donor. In 2018, this guideline was changed to a maximum of 12 families per donor. To avoid confusion when determining whether this guideline on the maximum number of offspring per donor has been exceeded, the maximum of 25 offspring per donor has been taken as the starting point. After all, the aim both before and after 2018 was to limit the number of offspring per donor.

Guideline exceeded in the Netherlands

There are 23,941 ongoing pregnancies registered in the CDKB register, an ongoing pregnancy being a pregnancy of at least 12 weeks. The number of unique registered donors is 4,684. Of these, 85 (1.8%) have more than 25 offspring.

Of these 85 donors:

49 donors were active at one clinic,
28 donors were active at 2 to 5 clinics.
8 donors were active at more than 5 clinics.

In total, these 85 donors are involved in 2,998 registered pregnancies and 2,175 mothers.

Reasons for exceeding the limit

National picture

There are 31 donors with 25-30 offspring.
There are 42 donors with 30-40 offspring.
There are 6 donors with 40-50 offspring.
There are 5 donors with 50-75 offspring.
There are no donors with 75-100 offspring.
There is one donor with 100-125 offspring.
There is no donor with more than 125 offspring.

Situation at our clinics

The limit has also been exceeded at our clinics. In the tabs below, we provide more insight into the situation at our clinics.

Elsendorp (Nij Geertgen)

The national registration shows that the guideline was exceeded* for 25 donors. This includes 2 donors from our own bank.

Dutch donors exceeding the guideline
The Dutch donors were all active at several Dutch clinics, including Nij Geertgen (and/or Stichting Geertgen). At Nij Geertgen, this resulted in 168 registered pregnancies.

Foreign donors exceeding the guideline
The other 15 foreign donors were also active at 2–7 Dutch clinics, including Nij Geertgen (and/or Stichting Geertgen). At Nij Geertgen, this resulted in 182 registered pregnancies.

*The guideline is exceeded when there are more than 25 registered ongoing pregnancies.

Wolvega (Nij Barrahûs)

The national registration shows that the guideline was exceeded* for 12 donors. None of these donors are from our own bank.

Dutch donors exceeding the guideline
The Dutch donor was active at a total of 3 clinics, including Nij Barrahûs. At Nij Barrahûs, this resulted in one registered pregnancy.

Foreign donors exceeding the guideline
The other 11 foreign donors were also active at 3–7 Dutch clinics, including Nij Barrahûs. At Nij Barrahûs, this resulted in 42 registered pregnancies.

*The guideline is exceeded when there are more than 25 registered ongoing pregnancies.

Gorinchem (Nij Linge)

At Nij Linge, the guideline has not been exceeded*.

*The guideline is exceeded when there are more than 25 registered ongoing pregnancies.

Information about your situation?

If you would like more information as a parent or donor, please contact us. We aim to get back to you within one month at the latest.

You will receive an e-mail from us with specific information about your situation. If you would prefer to hear this information in person, you can indicate this in the form below.

Requesting information
How you can request more information depends on your personal situation:

Donors and parent(s): from us via the form
Donor-conceived children aged 16 and over: via the website of the CDKB
Donor-conceived children under 16: from us via the form

You are requesting this information as: *

Reason for contact: *

Full name *

Citizen service number (BSN) (last 5 digits) *

Applicant's date of birth *

Address *

Postcode *

Email address *

Phone number *

Contact preference *

Where were you treated? *

At which clinic did you donate? *

Year donation started *

Year treatment(s) started *

Additional information

Please bear in mind that these numbers are based on the data currently registered with the CDKB. Treatments may still take place with a donor's sperm if the maximum of 12 women per donor has not yet been reached. For treatments before 2004, on the other hand, it is not certain whether all treatments were registered with the CDKB, because the Artificial Fertilisation Donor Data Act did not yet exist at that time.

Reasons for exceeding the limit

There are several reasons why the limit has been exceeded:

A donor may already have had 25 offspring while a woman wanted a second or third child from the same donor. With a view to completing families, clinics often accommodated this wish.
If the donated sperm had been used for IVF/ICSI treatment, embryos were stored where necessary. Because the woman has control over these embryos, they were later used for a second or third child without taking into account the number of offspring the donor in question already had.
The number of pregnancies registered by clinics does not necessarily correspond to the number of children born: if a pregnancy ended in a miscarriage or stillbirth, it was not always removed from the system. In addition, one registered pregnancy may have resulted in more than one child.

In the past, donated sperm was exchanged between clinics. Reasons included the woman moving house, a second opinion elsewhere or exchange between sperm banks. Treatment data was not exchanged between the clinics concerned, possibly for privacy reasons.
In addition, the revised registration system has revealed that some donors were active at several clinics without the clinics being aware of this. In some cases, this was already known and clinics had stopped using the donor concerned.

More information?

News about a large number of half-siblings can have an impact on families and donors. The website of Fiom, a centre of expertise on questions of kinship and origins, offers guidance on how to deal with this. You can also contact Fiom for short-term support.

Information on this subject can also be found on the websites of the National Donor Conception Information Point (Landelijk informatiepunt donorconceptie, LIDC) and the CDKB.

Donor bank contact

Do you have questions, or would you like more information about donating or ordering donor material? Feel free to contact our donor bank.

Our specialised team is ready to help and support you at every step of the process.

Contact