Slowing the biological clock won’t solve family planning dilemmas
In future, women could remain fertile for longer by undergoing an ovarian tissue transplant, according to a paper published in April 2012 by American and Danish researchers.
The Reproductive Biomedicine paper reports that three women who received ovarian tissue transplants in Europe and the United States have given birth to eight children between them. The women had experienced either treatment for cancer or premature menopause.
Two women had their tissue frozen and the third had fresh tissue transplanted, which was donated by her sister. The authors conclude that the success of these procedures indicates that, in future, healthy women could use ovarian tissue freezing and transplantation to halt the natural decline in fertility that occurs once a woman reaches her early- to mid-30s.
They claim that the procedure could also allow women to postpone menopause – and its potentially debilitating symptoms – for up to seven years. But while these data are encouraging for women facing compromised fertility when they are of reproductive age, ovarian tissue freezing and transplantation are still experimental and the “success” of the study (defined in the paper as live births) remains limited.
Cancer and infertility
The usual context for removing and freezing ovarian tissue in Australia (and other countries with well-resourced health systems) is a diagnosis of cancer and the prospect of infertility. For some women diagnosed with cancer who hope to become pregnant later, freezing ovarian tissue may be the only option.
Some cancers are exacerbated by the hormones used in IVF treatment. In these circumstances, women can’t have eggs collected before cancer treatment, so the prospect of a future ovarian tissue transplant provides some hope, even if pregnancy cannot be guaranteed.
There is a continuing trend in Australia and and other high-income countries for women to give birth at an older age. Of women who had their first birth in 1998, around a third were aged at least 30. But by 2008, this proportion had increased to 42 per cent. Likewise, more women are giving birth aged over 35 - from 16 per cent in 1999 to 23 per cent in 2008.
Women’s fertility has not, however, extended. So biology and society are increasingly out of step. It is in this context that some women look to assisted reproductive technologies to extend their window of fertility.
Some obstetricians and media commentators have criticised Australian women for delaying children in order to pursue personal ambitions or hedonistic activities such as travel. But the evidence suggests that this is an oversimplified and inaccurate view.
It is true that few women are having babies as adolescents. But almost all Australian women aged 30-34 want to have children. The main reason for not becoming pregnant is the absence of a partner or being unable to find a partner who is prepared to commit to having children, rather than personal ambition.
Concerns have been raised that enabling women in their fifties and sixties to conceive will lead to a generation of children whose parents will be too old to care for them. But very few women seek post-menopausal motherhood; most “older” women pursuing assisted conception are in their early 40s.
Is surgery the answer?
It is theoretically possible that, in the future, a woman in her 20s who knows that she wants to conceive – but wants to wait or hasn’t found the right partner – might choose to have some ovarian tissue frozen as a precaution. She might even contemplate freezing ovarian tissue to have it re-grafted, to protect against symptoms of menopause.
But the technique won’t be a panacea for extending fertility. First, these procedures are not without risk; both tissue harvesting and transplantation require anaesthetics and surgery and there are significant financial costs to storing any reproductive tissue.
Second, in order to be most effective, the procedure would have to take place while women are young, so ovarian tissue can be frozen before fertility declines. Healthy young women would therefore need to undergo a costly technique that is neither guaranteed nor free of risk.
The realities of fertility
There are much less risky and more assured strategies open to women and men of reproductive age than surgery. Most of this comes down to education and communication.
We need to be aware that fertility declines with age - in women from the age of 35 and in men about a decade later. Men and women can preserve their fertility by maintaining a healthy weight, avoiding tobacco and keeping alcohol consumption at a safe level.
There’s even a strong case for information about fertility preservation to be included in sexual health education classes, alongside content on preventing unintended pregnancy and building strong relationships.
Couples can feel inhibited about discussing desires to have or not to have children early in their relationships. But one of the most important skills for women and men of reproductive age to develop is the ability to initiate conversations about fertility and family formation.
Content reproduced from The Conversation, with permission, 13 April 2012.
Andersen et al. Reprod Biomed Online. 2012 Apr 9 [Epub]
Jean Hailes press release: Most Australians don't know when fertility starts downhill slide
Your Fertility website