have been given. Donors are asked to provide a pen portrait of themselves which is held by the HFEA and can be obtained by the adult conceived from the donation at the age of 16, along with identifying information such as the donor's name and last known address at 18. Known donation is permitted and it is not uncommon for family or friends to donate to a recipient couple. Qualities that potential recipients typically prefer in donors include the donors being tall, college educated, and with a consistently high sperm count. A review came to the result that 68% of donors had given information to the clinical staff regarding physical characteristics and education but only 16% had provided additional information such as hereditary aptitudes and temperament or character. Other screening criteria Sexually active gay men are prohibited or discouraged from donating in some countries, including the US. Sperm banks also screen out some potential donors based on height, baldness, and family medical history. Number of offspring Where a donor donates sperm through a sperm bank, the sperm bank will generally undertake a number of checks to ensure that the donor produces sperm of sufficient quantity and quality and that the donor is healthy and will not pass diseases through the use of his sperm. The donor's sperm must also withstand the freezing and thawing process necessary to store and quarantine the sperm. The cost to the sperm bank for such tests is considerable, which normally means that clinics may use the same donor to produce a number of pregnancies in multiple women. The number of children permitted from a single donor varies by law and practice. These laws are designed to protect the children produced by sperm donation as well as the donor's natural children from consanguinity in later life: they are not intended to protect the donor himself and those donating sperm will be aware that their donations may give rise to numerous pregnancies in different jurisdictions. Such laws, where they exist, vary from jurisdiction to jurisdiction, and a sperm bank may also impose its own limits. The latter will be based on the reports of pregnancies which the sperm bank receives, although this relies upon the accuracy of the returns and the actual number of pregnancies may therefore be somewhat higher. Nevertheless, sperm banks frequently impose a lower limit on geographical numbers than some jurisdictions and may also