Italy’s strict law on assisted reproduction has reduced some women’s chances of conceiving because doctors can no longer select the best embryos for IVF treatment, researchers said on Tuesday.

The 2004 law allows only three eggs to be fertilised at a time and all must be used in treatment. It also bans embryo freezing and research as well as egg and sperm donation.

Italian fertility experts who oppose the legislation said that since it was enforced, there have been fewer successful pregnancies resulting from infertility treatments and more multiple births in some women.

“There is for some (women) a decrease in the cumulative pregnancy rate,” said Dr. Laura Rienzi, of the European Hospital in Rome.

Because the law requires all the fertilised eggs to be transferred to the womb, it raises the odds of multiple births.

Last week, voters in Italy - where birth rates are among the lowest in Europe - failed to pass a referendum that would have dismantled the legislation. It was seen as a victory for the Vatican, which had urged Catholics to abstain from voting.

Only about 26 percent of Italians went to the polls.

“This is a victory of apathy and indifference,” Dr. Monica Cattoli, from the Tecnobios Procreazione fertility clinic in Bologna, told a meeting of the Human Society of Human Fertilisation and Embryology.

“Italy is a modern-day state and should not allow the interference of religious authorities in its affairs.”

Fertility experts described it as a sad day for infertile couples and warned that the Vatican, buoyed by its success, is likely to take a stronger stand against biomedical research and treatment in other countries where it has an influence.

Rienzi compared results of infertility treatments before and in the four months after the law was enforced.

“Our results showed that the requirement to transfer all the embryos obtained, without any selection, has reduced the chances of obtaining a full term pregnancy,” she said.

The cumulative pregnancy rate before the law was 38.7 percent but fell to 30.2 percent afterwards.

The researchers believe the drop is due to the different quality of the embryos used in the treatment. The chances of a pregnancy have diminished even in patients with a good prognosis.