Four women have given birth to healthy babies after their eggs were genetically screened using a technique that offers hope to childless couples.

The quartet was taking part in a pilot study to test the effectiveness of comparative genomic hybridisation (CGH) by microarray, a new method of looking for chromosomal abnormalities in eggs. The success could pave the way for women with a history of failing to become pregnant using in-vitro fertilisation (IVF).

The technique could also make it easier for women to give birth later in life, when there is less chance of becoming pregnant. But doctors involved in the trial stress that it can help them only to identify viable eggs, and does nothing to improve the chances of producing high-quality eggs in the first place.

The European Society for Human Reproduction and Embryology (Eshre) announced yesterday that women at two centres in Bonn, Germany, and Bologna, Italy, had given birth to healthy babies after undergoing array CGH. The German patient, aged 34, gave birth to twin girls in June. Three months later, the 39-year-old woman in Italy gave birth to a baby boy.

Later it was revealed that two more women aged 37 at the Bonn centre had given birth to single babies in August. Several other women from the total of 41 taking part in the study are said to be at advanced stages of pregnancy.

Eshre chairman Professor Luca Gianaroli said: "The whole world of IVF has been trying to find an effective way of screening for these abnormalities, but results so far have been disappointing with the technology available.

"Now we have a new technology in array CGH, and our hopes are that this will finally provide a reliable means of assessing the chromosomal status of the embryos we transfer."