A French health ministry experts' study into reported clusters of babies born with missing or malformed upper limbs in three separate regions of rural France has failed to establish the cause. “We don’t know what we’re looking for,” said one of the panel of experts. The study has caused outrage among families of the malformed infants, born without arms or hands, after it decided one of the clusters did not meet the medical criteria of the term, and ruled out a number of proposed measures to further research into the problem at a national level. Amid speculation that environmental factors, such as pesticides, may have played a role, the experts said there was “currently insufficient” knowledge of the issue to draw a conclusion. François Bonnet reports.