IVF or other ART treatments, they may reduce the charge if a patient donates any spare embryos which are produced through the treatment. There is often more demand for fertility treatment with donor sperm than there is donor sperm available, and this has the effect of keeping the cost of such treatments reasonably high. Onselling There is a market for vials of processed sperm and for various reasons a sperm bank may sell-on stocks of vials which it holds (known as 'onselling'). Onselling enables a sperm bank to maximize the sale and disposal of sperm samples which it has processed. The reasons for onselling may be where part of, or even the main business of, a particular sperm bank is to process and store sperm rather than to use it in fertility treatments, or where a sperm bank is able to collect and store more sperm than it can use within nationally set limits. In the latter case, a sperm bank may sell on sperm from a particular donor for use in another jurisdiction after the number of pregnancies achieved from that donor has reached its national maximum. Psychological issues Informing the child Many donees do not inform the child that they were conceived through sperm donation, or, when non-anonymous donor sperm has been used, they do not tell the child until they are old enough for the clinic to provide contact information about the donor. Some believe that it is a human right for a person to know who their biological mother and father are, and thus it should be illegal to conceal this information in any way and at any time. For donor conceived children who find out after a long period of secrecy, their main grief is usually not the fact that they are not the genetic child of the couple who have raised them, but the fact that the parent or parents have kept information from or lied to them, causing loss of trust. There are certain circumstances where the child very likely should be told: When many relatives know about the insemination, so that the child might find it out from somebody else. When the adoptive father carries a significant genetic disease, relieving the child from fear of being a carrier. The parents' decision-making process of telling the child is influenced by many intrapersonal factors (such as personal confidence), interpersonal factors, as well as social