An Australian woman, who attracted media attention in 2005 after giving birth to a second set of quadruplets, has given birth again to a set of twins. According to the newspaper, The Australian, Mrs Chalk, 31, has had eleven children conceived using an anonymous sperm donor and artificial insemination, although there are conflicting reports that she may have undergone IVF (in vitro fertilisation). The treatment was given at a private clinic in Queensland.

Mrs Chalk was criticised by some for having the number of children her and her partner, Darren, chose to have. The Fertility Society of Australia took an interest in her case and the IVF Directors' Group issued criticism of the clinic in 2007 as being financially and clinically irresponsible, the Courier-Mail reports. But bioethicist Nicholas Tonti-Filippini at the John-Paul II Institute in Melbourne supported Mrs Chalk's reproductive decision-making. 'It's not up to the government or anybody else to tell people how many children they can have,' he said.

Although it is uncertain if Mrs Chalk did in fact undergo IVF, the case highlights the issue of multiple births which carry increased health risks to both mother and child. Clinics in the UK are advised by the regulatory body - the Human Fertilisation and Embryology Authority - that it is good practice to transfer only one embryo at a time and that multiple embryo transfer does not necessarily increase the chances of pregnancy, but does increase the risk of multiple births. Some commentators in Australia are concerned that financial pressures on fertility patients may persuade them to opt for multiple embryo transfer. 'What might be interesting is whether the Federal Government attempts to decrease Medicare funding to IVF. We certainly hope this does not drive patients to ask for more embryos to be put back in,' said Gino Pecoraro of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists. 'People might be tempted to have more babies at once, thinking that might be cheaper. But the health implications are significant. That would be a major failing of the system and we don't want that to happen.'

The Chalks have told reporters that they do not have any more plans for further children. 'We'd love to have more children, but medically, that's it,' Darren Chalk said, adding: 'We'd have to buy a bigger bus!'