The research, in the journal Nutrition & Dietetics published by Wiley-Blackwell, found expectant mothers are eating less than half the recommended serves of fruit and vegetables. And at least one in three put on more than the recommended weight gain for pregnancy.
Researchers Shelley Wilkinson and Debbie Tolcher surveyed 304 women who attended Australian maternal health services during or just after pregnancy.
"Many of the pregnant women in our study had poor diets, placing them at a higher risk of unhealthy weight gain, high blood pressure, and anemia during pregnancy. And a poor quality diet in pregnancy has been linked with lower birth weight and an increased long-term risk of chronic disease in babies," said Dr Wilkinson, an Accredited Practising Dietitian.
She said pregnancy was the ideal time to adopt a healthy diet, with the potential to impact on the health of two generations.
Co-author Debbie Tolcher said: "Expectant mums need plenty of vegetables, fruits, and wholegrain breads and cereals, and moderate amounts of reduced-fat dairy foods and lean meat (or alternatives, like legumes). This will help them gain a healthy amount of weight and meet their needs for nutrients like protein, iron, iodine and folate.
"Around 55 per cent of the pregnant women in our study wanted to learn about good nutrition. But only a small number had access to a dietitian, either during pregnancy or after the birth of their baby, for advice on healthy eating and healthy weight gain in pregnancy."
Commenting on the research, Dietitians Association of Australia (DAA) CEO Claire Hewat said: "Because pregnant women are seen as 'healthy' there are very limited dietetic resources allocated to this area.
"Prevention is better than cure so we are missing a great opportunity to influence the health not only of mothers but also of their unborn babies at a time when they are most likely to be receptive to change. DAA would like to see more funding for maternal health dietitians, as pregnant women deserve better."
The research revealed more than one third of the women were overweight or obese at the beginning of their pregnancy, and few knew their recommended pregnancy weight gain range.