A University of Adelaide study has found asthmatic women who eat a high-fat, high-sugar diet are more likely to have uncontrolled asthma while pregnant.

Dr Jessica Grieger from the University's Robinson Research Institute says diet is important for all women planning to start a but it's even more essential for women with asthma.

"Asthma is a common chronic condition, affecting 8-13% of the population, but many people don't realise that asthma during pregnancy can be very dangerous for both the mother and the baby – even more so if the asthma is poorly managed," says Dr Grieger.

"Asthmatic women are up to 54% more likely to develop pre-eclampsia during pregnancy, have their baby early and deliver a baby of low birth weight. And having an while pregnant can endanger a baby's life.

"In our research, we looked at the pre-conception diet of with asthma and found that those who regularly ate fast food, fried potatoes, crisps and refined grains were more likely to have ," she says.

Dr Grieger says women with asthma can dramatically reduce the risk of by effectively managing their asthma.

"It's important to have a healthy diet of lean meat, poultry and fish, and lots of whole grains, fruits and vegetables before getting pregnant because we know that women rarely change their diet once they become pregnant," says Dr Grieger.

"Asthma can change when a woman becomes pregnant, with 50% of women experiencing a worsening of asthma as pregnancy progresses.

"Asthma can be managed well during pregnancy with regular use of preventer medication, regular visits to the doctor when asthma flares up, and by eating a healthy and well-balanced diet.

"Women with moderate and severe asthma should also have a current asthma action plan (which can be prepared alongside a doctor), and this is even more important for pregnant women," she says.

More information: "Asthma control in pregnancy is associated with pre-conception dietary patterns." Public Health Nutrition DOI: dx.doi.org/10.1017/S1368980015001226

Journal information: Public Health Nutrition