Poorer women are twice as likely as those in higher income groups to be obese after childbirth, according to new Irish research.

According to researchers at UCD and the RCSI, mothers who are obese after birth are more likely to have a low household income, are more likely to be smokers, not to have breastfed their babies for long after birth and to have left education early.

According to one of the lead researchers, Prof Michael Turner of Dublin's Coombe Hospital, the results of the study should have implications for the way in which the State and civil society deliver and communicate public health campaigns relating to maternal and post-childbirth (post-partum) health.

Prof Turner said the results highlighted the need to direct public health policy on obesity in women with children towards high-risk groups, particularly from those who are socio-economically disadvantaged.

He said the study showed that the more children that poorer women had, the more likely they were to be obese, but there was no such association among better-off women.

Prof Turner added that tackling the problem of postpartum obesity was becoming increasingly important due to the association between obesity and complications in pregnancy.

Co-lead of the research, Prof Richard Layte of the ESRI, said becoming a parent can bring with it lifestyle changes that can have serious implications for weight gain, the risk of diabetes in pregnancy and chronic diseases.

"Pregnancy can be a turning popint in lifetime health risks and this research shows that such risks are more concentrated among lower income groups."

Prof Layte suggested that healthcare professionals should invest more time and effort with lower income couples who are at greater risk of gaining weight.

More than 10,000 mothers living in Ireland took part in the study, which is published in the American Journal of Obstetrics and Gynaecology. The research forms part of the national Growing up in Ireland project