Egg and sperm donors must take a series of thorough medical examinations in order to verify the quality of their gametes and the absence of genetic disorders and any other infection. For this reason, it is only logical to think that getting pregnant is easier using donated eggs and/or sperm.
In fact, and especially among women older than 37, egg donation poses a real improvement in the chances of conceiving. As for using donor sperm, it is determining for reaching reproductive success in cases of severe male infertility problems.
Artificial insemination by donor
Most common performed technique when using donor sperm is artificial insemination, especially among single women. In fact, in case the woman does not suffer from severe fertility problems, she presents tubal permeability and regular menstrual cycles, donor insemination is the most recommended method to achieve pregnancy due to its low complexity.
Success rates of artificial insemination using donated sperm are high, since sperm is of optimal quality. Nevertheless, it depends also on another factors such as the medication administered to trigger egg production and the woman’s age.
As a woman gets older, her reproductive potential drops principally due to a reduction in the quality and the quantity of her eggs. Thus, after an ovarian hyperstimulation cycle, one might say that live birth rates within the US are around the following:
- 15% among women under 35
- 11% among women between 35 and 37
- 9% among women between 38 and 39
- 5% among women aged 40 or over
It is important to keep in mind that medications used for ovarian stimulation help rise these rates, putting them at about 20 to 30% among younger-than-35 women. Checking whether the woman presents any problem. Using donor-sperm IVF instead of artificial insemination is recommended in case the woman presents some problem, there is any sperm pathology, or there is no male partner.
Finally, it is worth stressing that donor insemination cycles have a cumulative success rate, that is to say, it increases as a new cycle begins up until the fourth cycle approximately. General cumulative rates range from 60 to 80%.
Achieving pregnancy with donor eggs
When resorting to donor eggs to become pregnant, the success rates of the fertility treatment, that is, the percentage of embryo transfers that lead to live birth depends on several factors such as:
- Egg donor age
- Number of eggs obtained
- Sperm quality (either own or donated sperm)
- Health status of the recipient
- Number of transferred embryos
Cumulative live-birth rates from fertility clinics have been studied by the SART (Society for Assisted Reproductive Technologies) at a national level, i.e. fertility clinics from the US. The results show a success rate of fertility treatments using donor eggs standing near 55%. This percentage was obtained from a study where 9,485 embryo transfers were analyzed —being 2 the average number of embryos transferred.
Bearing in mind that the number of eggs obtained from an egg donation cycle is high, the intended parents have the chance to preserve some embryos, i.e. embryo freezing or cryopreservation of embryos. This increases the success rate since it allows a greater number of attempts to be performed. However, embryo freezing decreases egg and embryo quality, although not significantly thanks to the incorporation of new technological advances.
Success rates of egg donation using frozen embryos are close to 40%, according to a study where 5,614 embryo transfers using frozen embryos from fertilizing donor eggs were analyzed.
Comparing success rates of in vitro fertilization using own eggs to those of IVF using donor eggs, we can see that egg donation substantially improves chances of having a child, especially among older women. In the case of women aged 40 and over, the likelihood of getting pregnant using donor eggs is 5 times higher than if it is performed with the woman’s own eggs.
It should be clear that the rates shown here are general. This means there are certain fertility clinics where success rates are independently higher and others that, conversely, count on lower rates for fertility treatments using donor eggs.