Joan Smith: Childless and happy? I am, and so are many others

Some people oppose fertility treatments on principle. They talk suspiciously about "designer babies" and "Frankenstein science", or have religious objections to the idea of doctors manipulating human embryos.

No one on that side of the argument is going to welcome a new technique called "three-parent IVF", which is designed to help couples affected by mitochondrial diseases to have healthy children. Last week, the Secretary of State for Health, Andrew Lansley, asked the Human Fertilisation and Embryology Authority to assess the controversial new treatment.

Mitochondria are present in every human cell and these couples risk producing children with serious and unpleasant conditions. The new treatment involves the transfer of human genetic material between two fertilised eggs, producing embryos which will have the nuclear DNA of their parents and the mitochondrial DNA of a donor; hence the "three-parent" tag. In fact, the amount of material from the donor would be very small, and as long as there aren't unacceptable risks to the embryo, it's hard to see why this form of treatment is more objectionable than other types of IVF.

What's rarely addressed in these deliberations are the unproven assumptions that drive IVF and the thriving fertility industry, or the impact on the wider population. A new fertility treatment is invariably accompanied by interviews with childless couples who say they feel their lives are incomplete; it's an argument that's been accepted without question, and IVF has for some time been available on the NHS, even though it's expensive and far from essential.

Not having children isn't an illness in the usual sense, and it certainly isn't a life-threatening condition, but fertility experts send women a hugely reactionary message. They encourage them to think they're failures if they don't have babies, implicitly dismissing any individual or couple who chooses to remain childless.

There's a very basic mistake here. For centuries, the fact that most women who had sex got pregnant perpetuated the myth of a universal maternal instinct. I don't have it and I know plenty of other women who don't. Quite a few men, I suspect, would be happy not to have children, but couples come under huge pressure from family and friends to start procreating. What few people – especially fertility doctors, most of whom are male and have massive egos – seem to realise is that there's no evidence for the assumption that having children makes people happy.

A commentary on the latest research highlights "the discrepancy between the widespread belief that children bring happiness and the fact that research finds either a negative or no significant relationship between parenthood and well-being". People think children will make them happy, but a new study shows that for parents under the age of 30, the level of happiness decreases with the first and each additional child. Parents in the 30-39 age group are no happier than childless couples.

Like the existence of a universal maternal instinct, the idea that life is pointless without children is a myth. Some childless couples feel the absence keenly and I don't have ethical objections if they opt to have IVF, but I'm not convinced that the NHS should pay for it. The idea of "designer babies" worries me less than the flawed rationale behind fertility treatment, not to mention the industry's cavalier disregard of its role in adding more children to our overcrowded world.

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