The number of cases that need to be reviewed of children taken into care on the basis of disputed medical evidence may be fewer than 200.

The one-month survey carried out by the Association of Directors of Social Services into 10,000 live cases handled by councils, due to be published in the House of Commons this week, was expected to reveal 40 in need of review.

It is expected that the full three-month review of around 40,000 cases will conclude that about 160 need to be looked at again.

Children's minister Margaret Hodge ordered the review after Angela Cannings was cleared of killing her babies in December 2003 following doubts over medical evidence (news, page 6, 10 June).