An increase in breastfeeding rates among disadvantaged mothers may have been boosted by policies supporting the practice introduced in the last decade, a new study suggests.

Mothers with few or no educational qualifications who gave birth in 2011 were far more likely to breastfeed for longer than similar mothers in 2005, the research suggests.

The Edinburgh University study showed that among women breastfeeding for six months or more, there was a 150% higher chance of mothers breastfeeding for longer in 2011 compared with 2005.

There was no similar improvement for women living in more socially advantaged circumstances over the study period, although these mothers already breastfed for longer.

The report said: "Breastfeeding duration increased the most among mothers with fewer educational qualifications, and mothers with no qualifications, in 2010-11 and were far less likely to stop breastfeeding early, compared with their counterparts in 2004-05."

Researchers said policies supporting breastfeeding which have been introduced in Scotland during the last 10 years may have contributed to the rise in disadvantaged mothers deciding to breastfeed.

Dr Valeria Skafida, of the Centre for Research on Families and Relationships at the University of Edinburgh, said: "In the past decade, the Scottish Government has developed several public health policies to promote breastfeeding.

"Changes have occurred at policy level, in national legislation, in hospitals and in healthcare staff training."

The study drew on national surveys of more than 5,000 mothers in 2005 and almost 6000 mothers in 2011, and assessed breastfeeding habits of mothers in the first 10 months of their babies' lives.