Pregnant women living in south Auckland are more likely than anywhere else in the country to have gestational diabetes.
In Counties Manukau Health's annual Women's Health and Newborn report, lead clinician for diabetes in pregnancy services, Dr Kara Okesene-Gafa, said the rates of diabetes in the area were a "growing concern".
"Due to the high rates of obesity in the area more mothers are developing the disease," Okesene-Gafa said.
In 2005, 3.1 per cent of woman in the area had gestational diabetes, but by 2015 the number had risen to 8.6 per cent.
Women who have the disease have an increased risk or developing major complications during pregnancy, Okesene-Gafa said.
"There are increased risks of miscarriage, congenital abnormalities, hypertension, stillbirth, difficult labour and delivery as well as a higher chance of their babies being admitted to the neo-natal unit.
"Women who experience gestational diabetes also have a 50 percent increased risk of developing type two diabetes in the next 10 years following," she said.
Malia Pasikala, from south Auckland, had been through eight pregnancies without complications and was told during her ninth she had gestational diabetes.
Higher rates of obesity is one reason behind the rise in gestational diabetes rates.
"I was really gutted when I found out because I thought it meant I would have diabetes for the rest of my life."
During the pregnancy, Pasikala said she began getting intense cravings for sweet and sugary foods but made changes to her diet and lifestyle following the diagnosis.
"Being a typical Pacific Islander, a lot of my diet consisted of big portions of meat and foods that were high in saturated fats so I'm incorporating a lot more veggies into my diet now."
Pasikala had to give her diet an overhaul after finding out she had gestational diabetes.
For women who had recently been told they had gestational diabetes, Pasikala said it was important to "not be afraid" of the condition.
"There's lots of help behind you, all you need to do is try your best to live a little healthier for the sake of both you and your baby."
Neonatologist Dr Chris McKinlay said one in 10 pregnant women in the Counties Manukau area would experience gestational diabetes.
"It's increasing every year - a lot of it is down to the number of overweight and obese women here, in Counties Manukau 43 percent of the women getting pregnant are considered obese."
While not every woman diagnosed with gestational diabetes was overweight or obese, McKinlay said the risk was "doubled" for women that were.
Another emerging concern was whether the condition was being diagnosed properly, McKinlay said.
"Currently we're investigating whether the thresholds for diagnosis need to be lowered - they haven't been changed here in 25 years and a lot of other countries have recommended lower thresholds.
"If we had these lower thresholds, the rates would double again," he said.
When a woman is diagnosed with the condition, McKinlay said her glucose levels would be monitored and she would also be given advice about healthy eating.
"From there we determine whether she needs further help, we recommend all pregnant women are screened for the condition between 24 and 28 weeks, but we're trying to pick up the risks earlier and figure out how we can best identify high risk patients."
Women who are overweight or obese who are thinking about getting pregnant should aim to lower thier BMI, McKinlay said.
"Women with a family history of type two diabetes should monitor how much weight they put on during pregnancy and talk with a midwife or maternity provider about any concerns.
"Maintaining a healthy diet during pregnancy can help decrease the risks too and I cannot stress enough how important it is to book a first pregnancy visit as soon as you know you're pregnant."