Yvonne Roberts: A bumpy ride in the fertility theme park

Dr Nayna Patel, a fertility doctor in Gujarat, India, last week announced that a 43-year-old woman had given birth to her own grandchildren. She had "lent" her womb to her daughter and son-in-law, producing test tube twins, a boy and a girl, adding a whole new meaning to the term "family planning".

The babies' parents, who live in Ilford, Essex, had searched in vain for a surrogate mother for four years. The woman's daughter, aged 26, suffers from Rokitansky syndrome. Although she has healthy ovaries, she has no womb. The grandmother had taken a month to ponder her decision before undergoing in vitro fertilisation (IVF). "I think it is perfectly ethical," Dr Patel said. "The grandmother was very motivated and very happy."

Providing offspring for the childless may bring joy - and those who yearn for a childexperience a great sense of loss - but the blind optimism packed into the phrase "perfectly ethical" is highly alarming, particularly coming from a fertility professional. Many issues arise from this neo-natal ménage à trois, not least the rights and welfare of the twins. The commodification of every aspect of life - whatever you want you can have, buy or acquire - doesn't remove fundamental concerns about the morality and dynamics of this brave new world.

The marriage of reproduction and technology has, of course, already turned the business of having babies into a fertility theme park, defying the laws of nature. The 43-year-old grandmother is not the first to provide offspring for a relative. In 1987, a South African gave birth to triplets, her grandchildren; a 54-year-old in the UK later became one of the oldest surrogate mothers, giving birth to a granddaughter.

Surrogacy, cloning, IVF and artificial insemination create family ties of a kind previously unknown. Too often, the child's needs are placed second to the desires of the adults. Yesterday, Priscilla Eatwell, 56, a grandmother, married to 70-year-old Don, announced that she intended to become pregnant with the help of a 27-year-old egg donor, Cherie Watts. "I want to be a mother again and I'm going to be," Mrs Eatwell said.

Recently, the 87-year-old father of the singer Julio Iglesias announced that his 40-year-old wife was pregnant, using IVF. At 13, the child, with luck, may have a father celebrating his centenary. And Diane Blood used her dead husband's sperm to father her two boys.

Every story, of course, is different but what each has in common is that in the hierarchy of need, those of the unborn child appear to have a low priority, while the health and rights of some of the women involved are also marginalised.

A common thread, for instance, is IVF - a nasty, invasive process which is thoroughly unpleasant to undergo, has a low rate of success, and may be associated with the onset of cancer in later life. Alarmingly, the 43-year-old woman in India had five embryos planted, a number forbidden in the UK. Surrogacy also raises fears of procreative exploitation. In The Mother Machine, Gena Corea writes of the flourishing of "breeder businesses" in the United States in the 1980s and the "renting" of wombs - with the unborn child described as "the tenant". Particularly prized were women from the third world, prepared to give birth for less, making surrogacy more commercially attractive to a larger audience.

"Baby booty", the commercialisation of the gift of life, dehumanises. In one court case in which the surrogate mother was resisting handing over "the goods", the judge referred to her as "the alternative reproduction vehicle". A study at City University, London, conducted last year, reported that most surrogate mothers found the experience "positive". Such research would resonate more with the human condition if a follow-up in 15 years' time questioned the children in these transactions.

If surrogacy involves a relative, it does, at least, solve the problem of quality control. You know what you're getting (lending a new sting to the line, "You're just like your mother"). On the other hand, it may make family dynamics even trickier. A 1970s bestseller was My Mother My Self: The Daughter's Search for Identity by Nancy Friday. "Why are women the way they are?" Friday wanted to know. "Where do the dependence, the longing for intimacy, the passivity come from? ... The key lies in a woman's relationship with her mother, that first binding relationship ... whose fetters constrain our sexuality, our independence, our very selfhood."

Women have changed and the fetters may have loosened, but the mother-daughter bond often remains fraught. How much more difficult when a profound debt and a "right" to interfere are added to the equation, now extended to my mother, myself and my children? (Although in the case of the 26-year-old from Essex, it probably helps that her mother is several thousand miles away.)

The consequences of the mother-daughter struggle can have a real and damaging impact on children. In Torn in Two: the Experience of Maternal Ambivalence, the psychotherapist Rozsika Parker describes how women repeat and repudiate their mother's treatment of themselves, in the way that they handle their own offspring. Parker's thesis is that all mothers feel both love and hate for their children, although society idealises mother love and makes anything less appear "bad". Guilty that they feel ambivalent, some women reared by critical, unloving mothers take vengeance on their own children. A vengeance which, arguably, is even more fearsome if the child is literally delivered by the cause of such contradictory emotions.

The 26-year-old and her mother may navigate these choppy maternal waters with maturity and understanding, but then comes a second challenge. How will the conception be explained, if at all, to the twins? In Sweden, eight out of 10 children born as a result of donor insemination are not told the truth. Some will grow up feeling that there is question mark over their identity. Emotional honesty is essential for a child's wellbeing but, too often, families instead prefer to make the cupboard bigger and add to the number of skeletons inside.

The more we focus on compensating for infertility using the ingenuity of man, the less we tackle the causes of infertility, often issues such as the pressure of a career, toxicity in the workplace and the abuse of the environment now seriously affecting the male sperm count. We worship control. Too many women spend 20 years swallowing the Pill to avoid conception, then another 10 taking drugs to manipulate their hormones to help them conceive at the "right" time. That's madness.

Motherhood is denied many when, for reasons of profit, it has never been more powerfully promoted. (A swollen belly is the must-have for any aspiring pop star.) But as Josephine Quintavalle from the pressure group Comment on Reproductive Ethics said last week: "Sometimes, the best way forward is to accept infertility, as harsh as that may sound."

Such a choice, however, requires a far stronger endorsement from society than exists at present. On the contrary, sadly, today's message is motherhood - no matter what the cost.