Women who eat a poor diet before they become pregnant may have an increased risk of giving birth prematurely, according to a recent study.

Researchers from the University of Adelaide in South Australia found that women who eat unhealthily before conceiving a child are around 50 percent more likely to have a preterm birth than those on a healthy diet.

Preterm birth is a leading cause of infant disease and death and occurs in approximately one in 10 pregnancies globally.

"Anything we can do to better understand the conditions that lead to preterm birth will be important in helping to improve survival and long-term health outcomes for children," Dr. Jessica Grieger, lead author of the study and postdoctoral research fellow with the Robinson Research Institute, said in a statement.

For the study, researchers investigated the dietary patterns of more than 300 South Australian women to better understand their eating habits before pregnancy.

They found that women who consistently ate a diet high in protein and fruit prior to becoming pregnant were less likely to have a preterm birth, while those who consistently ate high fat and sugar foods and takeaway were about 50 percent more likely to have a preterm birth.

"In our study, women who ate protein-rich foods including lean meats, fish and chicken, as well as fruit, whole grains and vegetables, had significantly lower risk of preterm birth," Grieger said. "On the other hand, women who consumed mainly discretionary foods, such as takeaway, potato chips, cakes, biscuits, and other foods high in saturated fat and sugar were more likely to have babies born preterm."

Researchers said diet is an important risk factor that can be modified.

"It is never too late to make a positive change. We hope our work will help promote a healthy diet before and during pregnancy. This will help to reduce the number of neonatal deaths and improve the overall health of children,"Grieger said.

The findings will be presented June 4 at the upcoming SA Annual Scientific Meeting of the Australian Society for Medical Research during ASMR Medical Research Week.