Yet almost two-thirds described their diet as "healthy". Experts say women need more information about how to meet food requirements amid a confusing maze of dietary restrictions recommended during pregnancy. University of Adelaide researcher Lenka Malek​, who completed the study as part of her PhD, said she did not believe the requirements were necessarily too difficult to meet, but many women weren't aware of them. "The research clearly shows that what women eat during pregnancy and around the time of pregnancy can influence the short and long-term health of their developing child," she said. "But even if women are aware that there are recommendations they don't necessarily know the specifics of what they say." Some recommendations, such as that women reduce the amount of certain types of fish to avoid mercury, may inadvertently lead them to avoid foods that were good for them.

In her study, nearly 30 per cent of the women said they were consuming less fish or avoiding it entirely since they became pregnant. Dr Malek said maybe recommendations to avoid certain fish should be changed in light of the findings. "Seafood has a relatively small impact on maternal blood mercury levels… fish is rich in n-3 fatty acids and other essential nutrients such as iodine and vitamin D; and positive associations [have been] found between fish intake during pregnancy and fetal neurodevelopmental outcomes," she wrote in her paper published in the journal Public Health Nutrition. Overall, the study found fruit was the food group women were most likely to consume enough of, with 56 per cent meeting the guidelines. The next most likely to be met was dairy, with 29 per cent meeting their requirements. Dietitians Association of Australia spokeswoman Milena Katz​ said many women may underestimate whether they met recommended food intakes because a "serving" was actually a lot smaller than most people thought.

But she said there was a need for GPs and midwives to provide dietary advice during pre-pregnancy and pregnancy check-ups. "Nobody in Australia is really meeting those guidelines, people aren't getting their recommended servings of vegetables, so it's not surprising that pregnant women aren't," she said. "You need to be very, very organised and well-planned, or have a very strict diet". But Ms Katz, who is an Accredited Practising Dietitian said she did not think this meant the guidelines were unrealistic. "The guidelines are evidence-based and they are there for disease prevention - this is what you eat to give your body the best chance for health," she said. "It's really a target people should aspire to". But she said it was easier to achieve if you assessed your intake over a longer period than just one day, and tried to add extra servings of fruit and vegetables to food you were already eating.

"It's also just about eating the food your kids are eating," she said. "Most mothers are really good at providing healthy foods for their children, but often they just don't get the chance to eat it themselves" The five food groups for pregnant women Five serves a day of vegetables and legumes/beans (Examples of one serve include half a cup of frozen veggies or one tomato)

Two serves of fruit (eg one banana and two apricots)

Eight and a half serves of grains (eg one slice of bread, half a cup of cooked brown rice, half a cup of cooked porridge)

Three and a half serves of lean meat, poultry, fish, eggs, nuts or beans (eg 65 grams of lean beef, two eggs, or 100 grams of fish)

Two and a half serves or milk, yoghurt, cheese and/or alternatives (eg one cup of milk or 40g of cheese) (Source: National Health and Medical Research Council)