Debate over diabetes in pregnancy

If the threshold for gestational diabetes is lowered then nurses will need more training to care for the increased number of patients, say experts. Flynn Murphy reports.

Up to 50 per cent more women could be diagnosed with gestational diabetes mellitus if new diagnostic guidelines being drafted by the Australian Diabetes in Pregnancy Society (ADIPS) are approved and implemented.

The new guidelines would bring diagnosis of gestational diabetes mellitus (GDM) into step with proposed criteria released by the International Association of the Diabetes in Pregnancy Study Groups (IADPSG) in 2010.

The international working group recommended a new diagnostic criteria that includes a lowered threshold for fasting blood glucose in the glucose tolerance test which mothers undergo 24-28 weeks into pregnancy.

Professor Robert Moses, director of diabetes services at the South Eastern Sydney and Illawarra Area Health Service and endocrinologist at Wollongong Hospital, told Nursing Review he had no doubt the current ADIPS criteria, which has been in place since 1991, was not strict enough.

The draft ADIPS guidelines recommend the threshold for fasting blood glucose be lowered from the current level of 5.5mmol/L, to 5.1mmol/L – a recommendation Moses has already enacted in Wollongong.

“If you take a group of women with no risk factors with gestational diabetes, 95 per cent of them will have a fasting level of less than 5[mmol/L]. Having a figure of 5.1[mmol/L] as the abnormal figure is just common sense.”

But while there is broad consensus on the need to update the criteria, questions remain over the ability of the medical system to cope, and what burden would be shouldered by Australia’s already overworked nurses.

“To change the diagnostic criteria is going to put an immense strain on everybody who deals with gestational diabetes,” said Dr Alison Nankervis, president of ADIPS and one of the people pushing for the change.

“The nurses who manage the women with gestational diabetes – it’s them who will notice the increased workload.” Nankervis warned that the new criteria could result in between 30 and 50 per cent more women being diagnosed with gestational diabetes.

Dr Glynis Ross, the immediate past president of ADIPS, and an endocrinologist in public and private care, told NR the system was already struggling. “In a lot of hospitals there is already major strain to cope with the numbers. Many hospitals are already not coping. And in private practice, which is only part of my job, I already get between two and eight new referrals a week. It can be overwhelming to find eight new spaces in a week.”

West Australian Australasian Diabetes in Pregnancy Committee (ADPC) member Cynthia Porter, a credentialed diabetes educator and dietician specialising in rural, remote and indigenous health, advocates decentralising the treatment of GDM as a way to take the pressure off of hospitals.

She said some of the GDM care needed to be shifted back to community GPs and community antenatal clinics, when it came to low-risk pregnancies.

Ross is sceptical. “There’s a massive range of ability and knowledge in general practitioners. There are some fabulous GPs out there, but most don’t know much about diabetes, and have absolutely no concept of general diabetes management or diet. The specific requirements for pregnancy are much greater. You’ve got to get the balance right.”

She said ongoing, supervised training was the only solution. “There aren’t enough dieticians, there aren’t enough [accredited diabetes] educators,” said Ross. “They’re just not around.”

“Up-skilling, rather than limiting scopes of practice, is the key,” said Porter. “Midwives, practice nurses and nurse practitioners can play a large role in GDM by keeping women in their home environments rather than relying on a tertiary centre.”

As part of her work with the ADPC, Porter explained she is pushing for GDM diagnostic tools that can be implemented in rural and remote areas.

Nankervis said regardless of the setting, nurses will shoulder a great deal of the burden of dealing with an increase in GDM diagnoses.

“They’ll be at the coalface. They do the bulk of the work, and they’re just amazing, and alongside diabetes educators they will need to educate these women on the role of exercise and diet, how to monitor their blood glucose levels and interpret them, and they will take phone calls to see how they are going, start them on therapy and consultation with their endocrinologist or their obstetrician if required.”

Nankervis said the number of women with gestational diabetes had already been increasing steadily due to demographic factors and the changing ethnic breakup of our community.
The re-evaluation of diagnostic criteria was informed by the results of the 2008 Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study published in the New England Journal of Medicine – a study of 23,316 women and first of its kind.

“Up until a few years ago, there was no uniformity about how we tested for and diagnosed gestational diabetes,” said Nankervis. “But in the study, the foetal outcomes determined to be of most significance were the weight of the baby, the fatness of the baby, and how much insulin the baby was making, and they showed very strong correlations with blood-glucose levels on their GGT [gamma-glutamyltransferase].”

Gestational diabetes can cause babies to grow too large, increasing the risk of birth injuries and complications in pregnancy, as well as increasing the likelihood of a caesarean. Aside from being in the top 10 per cent of body weight, babies born to mothers with GDM tend to have low blood glucose levels after they are born, and are more likely to suffer from jaundice and breathing problems. There is an increased risk of them being overweight at six years, and obese as teenagers. “It’s a lifelong thing for the babies,” said Nankervis.

Nankervis rejected as a “beat up” media reports that there has been conflict between ADIPS and the Australian Diabetes Society over a failure to reach consensus on the guidelines, a rejection supported by ADS president Professor Wah Cheung.

Cheung told Nursing Review the process had been consultative and collaborative, though he said that since the lowering of the glucose threshold was consensus-based, more evidence-based results were needed to determine the exact benefits of treatment for women diagnosed under the new criteria.

“It’s not adversarial in the least,” said Nankervis. Ross agreed: “It’s not people deliberately trying to delay things. If you don’t get the balance right, it could be wrong for 20 years.”

But for Moses there was no waiting for ADIPS. Under his direction, Wollongong Hospital implemented the international guidelines in January 2011. More than a year later, Moses said that his local area has seen a 40 per cent increase in the number of patients diagnosed with gestational diabetes. But he said in his hospital at least, the use of nurses and dieticians as the primary point of contact had helped them to cope.

Moses said their model incorporated both community and in-hospital care. “We normally arrange the clinic so there is a doctor present in another room at all times in case they need advice, which they require less all the time – or so if they need the very mechanical role of a prescription then there’s someone there. But this way the consultant is not the first contact.”

Moses said he expected this sort of care to be one of the primary roles of the nurse practitioner in the future.

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