The long-term health of mothers and babies is being put at risk by UK hospitals that have failed to introduce pro-breastfeeding policies, the United Nations says.

Unicef, the UN children's fund, today releases a report showing that four out of 10 maternity hospitals have not implemented guidance from the National Institute for Health and Clinical Excellence that was published a year ago.

Breastfeeding protects babies from a range of illnesses and saves the NHS millions of pounds a year, says Unicef. Breastfeeding also lowers a mother's risk of breast cancer, ovarian cancer, hip fractures and low bone density. Bottle-feeding puts babies at greater risk of gastrointestinal and respiratory infections and other illnesses, yet UK breastfeeding rates are among the lowest in Europe.

Nice recommended that all maternity trusts should adopt the Unicef Baby Friendly programme, which focuses on giving mothers information so they can choose whether or not to breastfeed, and ensuring they have support to do so. It is intended to be non-judgmental and women who elect to bottle feed will be helped to do it safely and well.

Unicef accredits hospitals that reach an acceptable standard. But some hospitals say budget cuts mean they cannot afford to train staff. Unicef points out, however, that Nice predicted cost savings for hospitals after three years of the initiative, because of reduced childhood illness.

Some hospitals have seen a transformation in attitudes after adopting the Baby Friendly policies. The Pennines acute trust has seen its breastfeeding rate rise from 29% in 1994 to 65%. "In 1994 women knew about formula milk but had no knowledge about breastfeeding," said Val Finigan, infant feeding coordinator for the trust. "We gave them information to enable them to make an informed decision." The other priority was to train staff at all levels to help women with whichever type of feeding they chose.

Unicef has this week written to all hospital chief executives, reminding them of the Nice guidance.