Women who conceived by IVF face higher risk of death during pregnancy and birth, a Dutch study has found. The reason is likely to be higher multiple births by IVF and older mothers using donor eggs.

The team found a death rate in Holland of 42.5 women per 100,000 live births through IVF compared to 12.1 women per 100,000 who had a non-IVF birth. Six deaths were directly attributable to IVF treatment.

But 'no more deaths directly related to IVF occurred in the Netherlands' after 1997, according to the study. The death rate amongst women in the study group was also lower than the general population, which they attributed to the 'healthy woman effect' - women undergoing IVF being more concerned about their health and a high socio-economic group.

The team from Radboud University in Holland used data about women undergoing IVF collected between 1984 and 2008. They estimated 100,000 IVF procedures had taken place during this period. The data about non-IVF births was collected between 1993 and 2003.

The study was published in Human Reproduction.