The study of more than 7,000 Australian women, published in Public Health Nutrition, is the first to examine the nutrient intakes of pregnant women who adhered to the recommended Listeria guidelines.
Researchers found that women who frequently ate a range of foods potentially containing Listeria had a 20 per cent greater risk of miscarriage than those who rarely ate these foods, but also had the highest intake of nutrients essential for a healthy pregnancy.
"This is quite a dilemma," said lead researcher, Professor Clare Collins*. "It is important for pregnant women to achieve a balance between an adequate intake of nutrients such as folate, iron, zinc and protein, and reducing their risk of Listeriosis.
"In our study, moderate or low consumption of foods at risk of contamination by Listeria was not associated with an increased risk of miscarriage, suggesting that a balanced consumption of potentially risky foods with foods containing essential nutrients may be the best approach."
Current Australian Government dietary guidelines recommend pregnant women and those trying to conceive avoid raw meat, unpasteurised milk, soft cheeses, pre-packaged salads, delicatessen meats and raw fruit and vegetables as they can be contaminated with the bacteria Listeria Monocytogenes. In pregnancy, this can lead to still birth, premature birth and miscarriage.
Professor Collins said the study findings suggested the need for a review of current Listeria recommendations to pregnant women.
"The recommendations need to include the list of ‘risky’ foods, but should focus on giving women low-risk alternatives to help them meet their optimal nutrient targets. It is also vital to emphasise the importance of safe food handling procedures.
"Women need to know how to balance opposing risks. We want them to feel confident about the foods they choose, so they minimise the risk of Listeriosis while giving their baby the best possible start to life."
Although the incidence in pregnancy is low, Listeriosis is considered an important public health issue due to the potentially serious impact on the foetus, including miscarriage, stillbirth, premature birth and neonatal infection. In 2008 approximately 65 cases of Listeriosis were reported in Australia, 12 during pregnancy and one of which was fatal.
*Professor Clare Collins is a Co-Director of the University of Newcastle’s Priority Research Centre for Physical Activity and Nutrition and a member of the HMRI’s cardiovascular program. HMRI is a partnership between the University of Newcastle, Hunter New England Health and the community.