Children conceived with sperm from former laboratory technician Henk Tachkerk said they felt abandoned by MCKinderwens in Leiderdorp. The clinic was accused of using his sperm in fertility treatments without authorization and registering it under the names of other donors. Tachkerk was also reported to have two hereditary abnormalities that could pose serious health risks to his children. The children rejected the final report on the case as inadequate and said they did not consider the matter closed.