Sperm bank processes

A sperm donor is usually advised not to ejaculate for two to three days before providing the sample, to increase sperm count. A sperm donor produces and collects sperm at a sperm bank or clinic by masturbation or during sexual intercourse with the use of a collection condom.

Preparing the spermedit

Sperm banks and clinics may "wash" the sperm sample to extract sperm from the rest of the material in the semen. Unwashed semen may only be used for ICI (intra-cervical) inseminations, to avoid cramping, or for IVF/ICSI procedures. It may be washed after thawing for use in IUI procedures. A cryoprotectant semen extender is added if the sperm is to be placed in frozen storage in liquid nitrogen, and the sample is then frozen in a number of vials or straws. One sample will be divided into 1–20 vials or straws depending on the quantity of the ejaculate, whether the sample is washed or unwashed, or whether it is being prepared for IVF use. Following analysis of an individual donor's sperm, straws or vials may be prepared which contain differing amounts of motile sperm post-thaw. The number of sperm in a straw prepared for IVF use, for example, will be significantly less than the number of motile sperm in a straw prepared for ICI or IUI and there will therefore be more IVF straws per ejaculate. Following the necessary quarantine period, the samples are thawed and used to inseminate women through artificial insemination or other ART treatments.

Medical issuesedit

Screeningedit

Sperm banks typically screen potential donors for genetic diseases, chromosomal abnormalities and sexually transmitted infections that may be transmitted through sperm. The screening procedure generally also includes a quarantine period, in which the samples are frozen and stored for at least six months after which the donor will be re-tested for sexually transmitted diseases (STIs). This is to ensure no new infections have been acquired or have developed during the period of donation. Providing the result is negative, the sperm samples can be released from quarantine and used in treatments. Children conceived through sperm donation have a birth defect rate of almost a fifth compared to the general population.

Samples required per donor offspringedit

The number of donor samples (ejaculates) that is required to help give rise to a child varies substantially from donor to donor, as well as from clinic to clinic. However, the following equations generalize the main factors involved:

For intracervical insemination:

${\displaystyle N=\frac{V_s\times <!--\; \times \; -->c\times <!--\; \times \; -->r_s}{n_r}}$

N is how many children a single sample can help give rise to.

V_s is the volume of a sample (ejaculate), usually between 1.0 mL and 6.5 mL

c is the concentration of motile sperm in a sample after freezing and thawing, approximately 5-20 million per ml but varies substantially

r_s is the pregnancy rate per cycle, between 10% to 35%

n_r is the total motile sperm count recommended for vaginal insemination (VI) or intra-cervical insemination (ICI), approximately 20 million pr. ml.

The pregnancy rate increases with increasing number of motile sperm used, but only up to a certain degree, when other factors become limiting instead.

With these numbers, one sample would on average help giving rise to 0.1–0.6 children, that is, it actually takes on average 2–5 samples to make a child.

For intrauterine insemination, a centrifugation fraction (f_c) may be added to the equation:

f_c is the fraction of the volume that remains after centrifugation of the sample, which may be about half (0.5) to a third (0.33).

${\displaystyle N=\frac{V_s\times <!--\; \times \; -->f_c\times <!--\; \times \; -->c\times <!--\; \times \; -->r_s}{n_r}}$

Only 5 million motile sperm may be needed per cycle with IUI (n_r=5 million)

Thus, only 1–3 samples may be needed for a child if used for IUI.

Using ART treatments such as IVF can result in one donor sample (or ejaculate) producing on average considerably more than one birth. However, the actual number of births per sample will depend on the actual ART method used, the age and medical condition of the female bearing the child, and the quality of the embryos produced by fertilization. Donor sperm is less commonly used for IVF treatments than for artificial insemination. This is because IVF treatments are usually required only when there is a problem with the female conceiving, or where there is a 'male factor problem' involving the female's partner. Donor sperm is also used for IVF in surrogacy arrangements where an embryo may be created in an IVF procedure using donor sperm and this is then implanted in a surrogate. In a case where IVF treatments are employed using donor sperm, surplus embryos may be donated to other women or couples and used in embryo transfer procedures. When donor sperm is used for IVF treatments, there is a risk that large numbers of children will be born from a single donor since a single ejaculate may produce up to 20 straws for IVF use. A single straw can fertilise a number of eggs and these can have a 40% to 50% pregnancy rate. 'Spare' embryos from donor treatments are frequently donated to other women or couples. Many sperm banks therefore limit the amount of semen from each donor which is prepared for IVF use, or they may restrict the period of time for which such a donor donates his sperm to perhaps as little as three months (about nine or ten ejaculates).

Choosing donorsedit

Information about donoredit

In the US, sperm banks maintain lists or catalogues of donors which provide basic information such as racial origin, skin color, height, weight, color of eyes, and blood group. Some of these catalogues are available via the Internet, while others are only made available to patients when they apply for treatment. Some sperm banks make additional information about each donor available for an additional fee, and others make additional basic information known to children produced from donors when those children reach the age of eighteen. Some clinics offer "exclusive donors" whose sperm is only used to produce pregnancies for one recipient female. How accurate this is, or can be, is not known, and neither is it known whether the information produced by sperm banks, or by the donors themselves, is true. Many sperm banks will, however, carry out checks to verify the information requested, such as checking the identity of the donor and contacting his own doctor to verify medical details. Simply because such information is not verifiable does not imply that it is in any way inaccurate, and a sperm bank will rely upon its reputation which, in turn, will be based upon its success rate and upon the accuracy of the information about its donors which it makes available.

In the UK, most donors are anonymous at the point of donation and recipients can only see non-identifying information about their donor (height, weight, ethnicity, etc.). Donors need to provide identifying information to the clinic and clinics will usually ask the donor's GP to confirm any medical details they 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 criteriaedit

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 offspringedit

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,clarification needed 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 limit the overall number of pregnancies permitted from a single donor. The limitation on the number of children which a donor's sperm may give rise to is usually expressed in terms of 'families', on the expectation that children within the family are prohibited from sexual relations under incest laws. In effect, the term family means a "woman" and usually includes the donor's partner or ex-partner, so that multiple donations to the same woman are not counted in the limit. The limits usually apply within one jurisdiction, so that donor sperm may be used in other jurisdictions. Where a woman has had a child by a particular donor, there is usually no limit on the number of subsequent pregnancies which that woman may have by that same donor.

There is no limit to the number of offspring which may be produced from private donors.

Despite laws limiting the number of offspring, some donors may produce substantial numbers of children, particularly where they donate through different clinics, where sperm is onsold or is exported to different jurisdictions, and where countries or jurisdictions do not have a central register of donors.

Sperm agencies, in contrast to sperm banks, rarely impose or enforce limits on the number of children which may be produced by a single donor partly because they are not empowered to demand a report of a pregnancy from recipients and are rarely, if ever, able to guarantee that a female may have a subsequent sibling by the donor who was the biological father of her first or earlier children.

In the media, there have been reports of some donors producing anywhere from over 40 offspring to several hundred or in one case, possibly over 1000.

Siblingsedit

Where a female wishes to conceive additional children by sperm donation, she will often wish to use the same donor. The advantage of having subsequent children by the same donor is that these will be full biological siblings, having the same biological father and mother. Many sperm banks offer a service of storing sperm for future pregnancies, but few will otherwise guarantee that sperm from the original donor will be available.

Sperm banks rarely impose limits on the numbers of second or subsequent siblings. Even where there are limits on the use of sperm by a particular donor to a defined number of families (as in the UK) the actual number of children produced from each donor will often be far greater.

Since 2000, donor conceived people have been locating their biological siblings and even their donor through web services such as the Donor Sibling Registry as well as DNA testing services such as Ancestry.com and 23andMe. By using these services, donors can find offspring despite the fact that they may have donated anonymously.

Donor paymentedit

The majority of donors who donate through a sperm bank receive some form of payment, although this is rarely a significant amount. A review including 29 studies from 9 countries found that the amount of money donors received varied from $10 to €70 per donation or sample. The payments vary from the situation in the United Kingdom where donors are only entitled to their expenses, to the situation with some US sperm banks where a donor receives a set fee for each donation plus an additional amount for each vial stored. At one prominent California sperm bank for example, TSBC, donors receive roughly $50 for each donation which has acceptable motility/survival rates both at donation and at a test-thaw a couple of days later. Because of the requirement for the two-day abstinence period before donation, and geographical factors which usually require the donor to travel, it is not a viable way to earn a significant income. Some private donors may seek remuneration although others donate for altruistic reasons. According to the EU Tissue Directive donors in EU may only receive compensation, which is strictly limited to making good the expenses and inconveniences related to the donation. A survey among sperm donors in Cryos International Sperm bank showed that altruistic as well as financial motives were the main factors for becoming a donor. However, when the compensation was increased 100% in 2004 (to DKK 500) it did not significantly affect the numbers of new donor candidates coming in or the frequency of donations from the existing donors. When the compensation was reduced to the previous level (DKK 250) again one year later in 2005 there was no effect either. This led to the assumption that altruism is the main motive and that financial compensation is secondary.

Equipment to collect, freeze and store sperm is available to the public notably through certain US outlets, and some donors process and store their own sperm which they then sell via the Internet.

The selling price of processed and stored sperm is considerably more than the sums received by donors. Treatments with donor sperm are generally expensive and are seldom available free of charge through national health services. Sperm banks often package treatments into e.g. three cycles, and in cases of 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.

Onsellingedit

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.