Diet prevents big babies in gestational diabetes patients

Diet prevents big babies in women with gestational diabetes
21 September 2017 | Pregnancy | Research and clinical trials

A healthy diet alone can control gestational diabetes and doesn't put the mother at greater risk of having a big baby, new research from the Royal Women's Hospital has found.

The study, published in the Journal of Pregnancy, paves the way for a change in how women with gestational diabetes (diabetes that develops during pregnancy) are managed by health care services with women who can meet blood sugar targets through dietary modification alone no longer considered as having a high risk pregnancy.

The research involved 202 women who were controlling their gestational diabetes with diet, and found their babies on average were slightly smaller compared to healthy pregnant women in the control group.


Lead researcher Dr Fatima Vally said the results were very exciting.

“Women with gestational diabetes can face an up to 50 per cent increased risk of having a large baby*, which comes with risks of possible complications such as injury to the baby and mother during delivery, emergency or planned caesarean delivery, and haemorrhage,” Dr Vally said.

“Babies also face a higher risk of low blood sugar levels and needing special care treatment after birth.

“However, our research has shown that with adequate dietary advice and regular blood glucose monitoring those risks are minimised as women who control their gestational diabetes through diet alone do not have an increased risk of delivering a big baby.”

The women with diabetes received medical and nutritional advice and support through the country’s first and largest dedicated Diabetes in Pregnancy Clinic at the Women’s.

Senior author and Head of the Women’s Diabetes in Pregnancy Clinic Dr Tom Cade said the research means that women successful at controlling their gestational diabetes without needing insulin, should no longer need ultrasounds to monitor the growth of their babies nor need early inductions of labour.

“This research shows that for many women with gestational diabetes, their dietician may be their most important health professional,” Dr Cade said.

“We can now make changes in our clinical approach, which, for our patients, means fewer inductions and visits with obstetricians, more opportunity to be cared for by their midwives and less fear about their condition. It is important to note that this approach is only suitable for women who are regularly testing their blood glucose and who meet their targets with suitable dietary modification.

“For health care providers, it means reduced costs due to a reduction in inductions, caesareans, admissions to special care and visits with clinicians. Our ultrasound department, in particular, is overwhelmed by requests for growth scans and this finding may allow this limited health care resource to be redirected to others in greater need.”

One in 10 pregnant women will develop gestational diabetes.

Marlouka von Eisenhart Rothe is due any day with her first baby and has been attending the Diabetes Clinic weekly.

“Initially I was worried when I was told I had gestational diabetes and feared I would have a big baby,” she said. “But after a few weeks of managing my diet my blood (glucose) returned to normal and my pregnancy has gone very well. My latest scan showed my baby is at a normal size.

“My diet means I need to avoid too many carbohydrates, have more vegetables and I need to eat every three hours.”

In future women like Marlouka won’t need such frequent hospital visits or scans.

Around one in 10 pregnant women will develop diabetes during their pregnancy. The diabetes ceases after the baby is born but these women face a much higher risk of developing permanent diabetes later in life.


Macrosomia rates in women with diet-controlled gestational diabetes: a retrospective study, has been published in the Journal of Pregnancy. The research was led by the Royal Women’s Hospital and involved the Royal Melbourne Hospital.

*Macrosomia or a big baby was defined in the publication's analyses as an estimated fetal weight >90th centile and >95th centile.

This study was funded by the Royal Women's Hospital.