"There has been a lack of data from well-designed, large randomised clinical trials on the effects of screening and subsequent treatment of women with mild gestational diabetes," Prof Crowther said.
"Our results show that treatment for these women in the form of dietary advice, blood glucose checks and insulin, if required, is beneficial for both the mothers and their babies.
"Care strategies to improve health of women and babies need appropriate evaluation in large, often multicentered clinical trials to be certain they do more good than harm.
"Our trial known as the ACHOIS - Australian Carbohydrate Intolerance Study - is the largest in the world to date, with 1000 women and 1030 babies recruited, and involving 14 hospitals in Australia and four in the United Kingdom," Prof Crowther said.
Gestational diabetes affects between two and nine percent of all women in pregnancy. For the women, having gestational diabetes is a strong risk factor for developing diabetes in later life. Risks for the baby of having a mother with mild gestational diabetes include being larger than average at birth which may lead to difficulties during birth and birth injuries.