For years the public has been wary of these arrangements. In recent months, though, there has been a shift in public opinion in Australia, sparked by Nicole Kidman's outing of her gestational carrier in the wake of her past fertility problems.
As increasing numbers of women hold off starting a family far past their fertility peak, and as gay men discover the joys of parenting, there has been a substantial increase in surrogacy arrangements globally.
Traditional surrogacy, where a man inseminates a surrogate mother to carry a child for his wife, was sanctioned by Babylonian law in 1760BC. Today it is possible for the intending parent to use their own eggs or those of a third-party donor. The absence of any biological link to the surrogate mum makes it easier for this woman to see herself as babysitting the child of another.
The remuneration of surrogates is legal and well regulated in many states of the US, Canada, India, Thailand and Iran. The American Organisation of Parents through Surrogacy estimates that 25,000 US babies were born through surrogacy in the 30 years to 2006. More than 1000 gestational surrogacy cycles take place in the US every year.
In Europe, more than 20,000 cross-border fertility treatments take place annually. There is now a professional body - the Society of Cross-Border Reproductive Care - which this year will host its second international congress in Macau, China. Europe has a bimonthly magazine, Fertility Road, devoted to intending parents in need of in-vitro fertilisation and surrogacy services. Overseas agencies report no shortage of applications from intending parents and surrogates alike.
In Australia, a recent survey of international surrogacy agencies has shown a 350 per cent increase in babies born via surrogacy during the past three years. More than 300 babies will be born to Australians via commercial surrogacy arrangements across the world in the year to June.
Many who have never met an infertile couple initially feel some anxiety about the notion. This is understandable. For surrogacy calls into question two traditional pillars of Western values: family and motherhood. Perhaps we are right to be a little uncomfortable. It is not a path chosen lightly. Intending parents see it as a last resort when IVF attempts and often adoption paths have reached dead ends.
Research demonstrates that couples with children born through surrogacy are in fact highly motivated and committed to their children. It also indicates that parenting outcomes for children born through surrogacy are equal or better when compared with parenting outcomes for children from traditional families, on all assessed indicators.
Such families include thousands of Australian women who have miscarried on multiple occasions or had a hysterectomy after cancer, and also include gay men, thwarted by inadequate adoption opportunities, who want to direct their energy and love into parenthood.
Some who oppose surrogacy would have us believe that such parents are choosing to avoid the messy inconvenience of parenthood. Try telling that to families with a child via surrogacy, dealing with dirty nappies, bottle feeds and toilet training.
And are surrogate mothers exploited? Do they suffer psychological harm once they give up the child to its biological parent(s)? As Stanford University professor of ethics Debra Satz observes "not all women 'bond' with their foetuses. Some women abort them."
Only a certain type of woman has the ability to give the gift of life to another. Such women are carefully screened to ensure they are unlikely to bond to the baby after delivery in the same way as biological mothers. The research confirms that during the pregnancy, surrogate mothers often form a relationship with the couple rather than the growing child. In the latest US research, the overwhelming majority report that carrying a child for another was important to them and very positive. .
Yet NSW has recently joined Queensland in deciding that the state should decide the appropriate way a family is created, by criminalising overseas arrangements, even in places where the practice is carefully regulated, such as California, as well as India, where a bill has just been passed to safeguard the practice there.
When Victoria criminalised surrogacy in 2006, Senator Stephen Conroy and his wife, Paula, who had had a hysterectomy following cancer, were faced with breaking the law. Instead they crossed the border to NSW to make their dream come true. Happily, they were one of the few couples for whom altruistic surrogacy proved viable, but their strategy was little different from those intending parents who now journey internationally.
While there is great discomfort among ethicists over the concept of compensating a surrogate mum for carrying a child, to the average intending parent, there is far more discomfort over not doing so.
Sam Everingham is co-convener of Australian Families Through Gestational Surrogacy.