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Egg donation - for donors | 
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As a result of treatment received between January 1995 and March 1996, 328 babies were born in the UK using donated eggs and 2,749 using donated sperm, with a further 68 born from donated embryos (already fertilised).
Source: HFEA
In normal couples the average fertility rate is around 25% per cycle. Couples are usually advised to wait at least a year before considering treatment. However, most women who require egg donation have no other chance of getting pregnant and no amount of time, patience, special diets or follicle stimulating drugs will make a difference.
There are several variants which affect the success of the treatment. It is more successful with younger women. It is more successful in older women if they are given a young woman's eggs. It is more successful if their partner has no fertility problems of his own. So it's hard to predict how successful the course of treatment may be for a specific person. Any treatment which can claim around a 25% success rate per cycle gives the same chance of a successful pregnancy as normal fertility would. It is fairly likely given these statistics that most couples will need several courses of treatment before a pregnancy is achieved. Two or three eggs are implanted in each cycle, and the need for eggs (as well as the cost) multiplies with each try.
The HFEA Guidelines advise that donated eggs should be frozen before being implanted in the recipient; some clinics choose not to follow this advice because approximately 1/3 of embryos do not survive the freezing process. In a clinic following these Guidelines, donors are given a blood test six months after the collection procedure has taken place and if it is HIV negative the implantation will proceed. Not all eggs fertilise following collection. Only eggs which have been fertilised and are developing normally will be implanted.
Statistics from the HFEA suggest that traditional IVF has a success rate of just under 20% (ie with eggs collected from the recipient partner). The success rate of egg donation is between 15-20%, although this depends on a variety of factors including the age of the donor, the age of the recipient, the experience of the doctors and so on.
Overall, success rates for IVF have steadily improved over the last ten years. Birth rates for IVF vary according to the expertise of the centers practicing this technique. However, centers in Europe have reported pregnancy rates after one cycle of IVF equal or superior to 25%. In 1993, the French IVF registry (FIVNAT) reported a pregnancy rate of 25.4% per embryo transfer on a total of 23,025 oocytes retrieved. Based on such results, after three to four cycles of IVF, a woman under 40 whose partner does not have any fertility problems could reasonably expect to give birth.
Source: Ferti-net
About a third of all pregnancies end in miscarriage. The chance of miscarriage does not seem to be higher for women receiving donated eggs, but from the point of view of interpreting statistics it means there are about a third more pregnancies than there are live births. If the pregnancy continues to term there is no evidence that children of donated eggs (fresh or frozen) are any less healthy than children born without medical intervention in their conception.
It can be very difficult to compare statistics because clinics tend to use figures which show them in a flattering light. Implantation rates (where the fertilised egg implants in the womb and a clinical pregnancy results) are 20-25% at best. But live birth rates, where the recipients get what is termed a 'take home baby' at the end of their treatment, are only a percentage of this - because of miscarriages and still births and other common prenatal problems. However some clinics will quote this pregnancy rate, which is often around 60%, without making it clear it is a percentage of a percentage, so it appears that they have a 60% success rate for their donor egg or IVF cycles. Effectively the success rate of egg donation, per cycle, resulting in a live birth, is 10-15%. If you're choosing a clinic to work with based on their success rates, make sure that you're comparing like for like and that you understand what the figures really mean. See GIVF for a detailed article about why success rates vary so much between different clinics, and how to understand the stats.
