If marriage leads to children, same-sex marriage must inevitably lead to surrogacy and exploitation.
A TV show called The New Normal will have its premiere on NBC in the US soon. It's about a gay couple and the single mother they engage to have their baby.
"She's just like an easy-bake oven except with no legal rights to the cupcake," the surrogate-mother broker tells Bryan and David. This is a hard-nosed description of the woman's role in gay marriage and child-rearing, but it sums it up accurately.
In heterosexual relationships, the birth rate rises when couples are married. One would expect similar dynamics to apply to same-sex couples. For lesbian couples, this is not a huge problem; all they need is a sperm donor. But male couples need surrogate mothers.
Where will these women come from?
Unless the law of supply and demand is repealed, the answer is: where wombs are cheapest. At the moment, this is India, where surrogate motherhood has become a $2.3 billion industry, with the enthusiastic encouragement of some state governments. A recent investigation by the London Sunday Telegraph found there were only 100 surrogacies in Britain last year, but 1000 in India for British clients. The proportion in Australia and elsewhere is likely to be the same.
There are no official statistics, but it appears gay couples account for a substantial chunk of the overseas market. So will the legalisation of same-sex marriage lead to even more surrogate mothers in India? BioEdge, the bioethics newsletter I edit, emailed IVF clinics in India and the US asking whether they were preparing for a rising demand for surrogate mothers.
The answer was a resounding yes. Our survey is far from scientific, let alone comprehensive, but it suggests that poor women in developing or economically depressed countries will be recruited to service gay couples.
"The main reason patients travel from abroad to India is for excellent personal care, expertise and a lot of savings on the treatment costs," says Dr Samundi Sankari, of Srushti Fertility Research Centre in Chennai. "The costs that they pay here is almost one-fifth the costs they pay for surrogacy in US and Europe." She gets a lot of inquiries from gay couples in the US and Israel. Is he preparing for an increase in demand? "Definitely, yes."
Dr Samit Sekhar, of the Kiran Infertility Centre, in Hyderabad, also forecast an increase. He said a ''sizeable number'' of the centre's clients were gay. ''We have seen an increase in the number of gay couples and single men approaching our clinic as soon as legitimacy to their public union is granted in their respective states or country."
There was one dissenting voice. A spokeswoman for Dr Shivani Sachdev Gour, of Surrogacy Centre India, Megan Sainsbury, rebuked BioEdge for its inquiry. "We are not preparing for an expansion of services for gay couples. Why would you ask this?" However, most of the contented parents featured on Sachdev Gour's blog last month are gay.
Indian IVF clinics say surrogate mothers are adequately compensated. But it can be a dangerous job, and the contracts they sign are weighted heavily in favour of the commissioning parents. A surrogate mother in Ahmedabad collapsed and died in May, shortly before she was due. The client took the baby and her family was given only $18,000.
The award-winning British/Indian novelist and journalist Kishwar Desai deals with the surrogacy industry in her latest novel, Origins of Love. She told The Guardian: "There are hospitals where women are kept for the whole nine months while they carry someone else's child. There are good stories, where the surrogate is well looked after, but I would like to make people aware of the sheer exploitation of it, the fact that these women are extremely poor. They are carrying someone's child for two or three thousand pounds [$3000 to $4500]. They may do this three or four times. They may be forced to have a caesarean."
A leading US infertility doctor, Jeffrey Steinberg, who runs the Fertility Institutes in Las Vegas and Los Angeles, told BioEdge he got a surge of inquiries whenever a jurisdiction legalised gay marriage. At the moment he uses only carefully screened American surrogates, but he is thinking of outsourcing their jobs to Mexico.
Supporters of same-sex marriage must recognise they face a serious moral dilemma. Cheap wombs might bring gay men the happiness of being the father of a child of their own. But the cost of that happiness is often borne by poor and uneducated women.
Michael Cook is the editor of MercatorNet. He also edits the bioethics newsletter BioEdge and is a columnist for Australasian Science. This article was originally published in the Sydney Morning Herald.