Eighteen percent of children aged 13 are being raised by a single parent, new figures show.

The data are contained in the Growing Up in Ireland-Key Findings: 13 year-olds report, which is part of an ongoing longitudinal study into the lives of Irish children.

The report also shows that 41pc of 13 year olds are being raised by stay-at-homes mothers. The more educated a mother is the more likely she is to be working outside the home.

The report first interviewed the children examined by the study when they were nine years old and then at age 13 years, when 7,400 were re-interviewed between August 2011 and February 2012.

According to the figures, 14pc of the children were being raised by a single parent when they were first interviewed and were still being raised by a single parent aged 13. An additional four percent went from being raised by two parents to being raised by just one parent.

Three percent of children went from being raised by one parent to being raised by two parents.  

Seventy nine percent of 13 year olds were still being raised in two parent families, having been in such a family structure since they were nine.

Overall, 81pc of 13-year-olds live in two-parent families.

The study also showed that single parent families had lower income levels than two-parent families.

Sixty two percent of single parent families with no more than two children and 77pc of such families with three or more children were in the lowest two income quintiles.  

This compares with 41pc of smaller two-parent and 48pc of larger two parent families.

Single parent families were much less likely to be in the highest income quintiles. Only seven percent of smaller and three percent of larger single parent families were in the highest income quintile compared with 19pc and 15pc of corresponding two-parent families.

Single parent families were also more likely to experience economic strain than two-parent families.  

Thirty-six percent of single parent families with no more than two children and 47pc of those with three or more children said they were experiencing great difficulty/difficulty in making ends meet. This compares with 19-20pc of two parent families.

Most families had been affected by the recession; 23pc said it had had a very significant effect while a further 38pc said it had had a significant effect on them. Only six percent said it had had no effect at all.

The study also showed that 31pc of these families said they could not afford, or had to cut back on basics; 13pc were behind with utility bills; and 11pc were behind with the rent/mortgage.