Contrary to the conclusions of previous studies, donating eggs to fertility clinic does not reduce the chances of women becoming pregnant later.
Out of a group of 60 women who had donated eggs, 54 later became pregnant within a year of trying to conceive, and three more women became pregnant within 18 months of trying to conceive, all without reproductive assistance, the findings showed.
The remaining three women in the study became pregnant with the help of fertility treatments. For two of these women, the treatments were needed due to fertility problems in their male partner.
Women who donate eggs are treated with hormones that ramp up their ovaries' egg production, and previous studies had suggested that fertility problems might follow in the wake of these hormone treatments, according to the study.
However, these previous studies had flaws in their design, so a more robust look at the issue was needed.
The question of how egg donation may affect future fertility is important not only for those who donate eggs to others, but also for women considering freezing their eggs to delay childbearing, the researchers said.
In the new study, researchers asked 194 women who had donated eggs at a fertility centre in Belgium questions regarding their attempts to become pregnant. On an average, the women's age at the time of their egg donation was 29, and their age at the time of the telephone survey was 34.
There were limitations to the study, the researchers said. Egg donors are a select group of women - women with fertility problems are unlikely to be able to participate.
Further, while the findings suggest that women's fertility after donating eggs is unaffected in the short-term, longer-term studies are needed to look at the possibility that the ovaries of these women age faster than usual, the researchers wrote.
The researchers noted that there is some evidence that the egg donation procedure, which involves puncturing the ovary, may cause the immune system to produce anti-ovary antibodies, and that higher levels of these antibodies have been seen in infertile women. Still, other studies have suggested that increase does not affect egg production, the researchers said.
They researchers noted that 16 percent of the women in the study reported changes in their menstrual cycle after egg donation, although none of these women reported fertility problems.
The story has been published online in the journal Fertility and Sterility.