Women who eat a diet high in animal fats and cholesterol before pregnancy raise their risk for gestational diabetes.
The study conducted by the National Institutes of Health also finds that not even healthy habits like exercise can override the effects of an animal fat diet.
Researchers say just by replacing five percent of daily calories with plant sources could reduce a woman's gestational diabetes risk by seven percent.
While animal fats were strongly linked to gestational diabetes, other kinds of fats did not pose an increased risk.
Gestational diabetes can cause pregnancy complications and health problems in newborns.