Studies also are beginning to uncover long-term risks for babies who develop during a hyperglycemic pregnancy. These infants appear to have double the risk of developing childhood obesity and/or metabolic syndrome, laying the foundation for adulthood rife with obesity- and diabetes-related health problems.
But when researchers examine the overall effect of a more stringent screening and diagnostic protocol, the view is somewhat cloudy, Dr. Reece said.
A 2011 study found that treating mild gestational diabetes was a cost-effective way of improving maternal and neonatal outcomes, including decreasing preeclampsia, cesarean sections, macrosomia, shoulder dystocia, permanent and transient brachial plexus injury, neonatal hypoglycemia, neonatal hyperbilirubinemia, and neonatal intensive care unit admissions (Am. J. Obstet. Gynecol. 2011;205:282.e1-7).
But a more recent study found that treating the condition only saves money when considering the mother’s long-term health.
"Our model demonstrates that [the new criteria] are cost-effective only when post-delivery care reduces diabetes incidence," wrote Dr. Erika Werner.
"When post-delivery care was not accomplished, the ... strategy was no longer cost-effective. ... Although there are potential perinatal benefits associated with the [criteria], these benefits alone do not justify the additional cost associated with tripling the number of GDM diagnoses in the U.S.," the authors wrote (Diabetes Care 2012;35:529-35).
The criteria’s biggest financial bang would come from their ability to detect occult diabetes in the mothers, Dr. Werner said in an interview.
"It would allow us to differentiate those women with underlying diabetes from those with only gestational diabetes. We’re missing these women now because very few ever come back for their postnatal diabetes screening," said Dr. Werner, a maternal fetal medicine specialist at Johns Hopkins University, Baltimore. Intervening early can be assumed to save much of the long-term financial costs of type 2 diabetes.
Her cost analysis isn’t set in stone, though, because it couldn’t control for the financial impact of either increased perinatal interventions – like cesarean sections – or the financial impact of preventing fetal consequences. And there’s no way to predict how many women who did develop diabetes postnatally would require insulin or oral medications, and how many could be conservatively managed with diet and exercise.
"We didn’t control for this because there are not data telling us that controlling glucose in pregnancy improves outcomes for women and neonates. The trends are there, but the confidence intervals are not. Any cost analysis is limited by the data that are out there. And in this case, we need more data," she said.
Dr. Reece agreed, saying only large long-term studies could provide enough of the evidence necessary to support changing the diagnostic algorithm.
But, Dr. Werner said, U.S. physicians might be able to learn from their international colleagues. "Some countries are already moving forward with them, and that will give us some of the additional data that we’re looking for."
Australia is one of those countries. The Australasian Diabetes in Pregnancy Society (www.adips.org) adopted the diagnostic criteria earlier this year, said Prof. Robert Moses, director of the Illawarra Diabetes Service in Wollongong, New South Wales. In a March editorial in the journal Diabetes Care, he likened the controversy over the recommendation to "opening Pandora’s box," adding that he supports the change, but that it needs to be thoughtfully applied, in a "clinically responsible way" (2012;35:461-2).
The change is expected to bump up Australia’s gestational diabetes incidence from 10% to 13%, Dr. Moses said in an interview. Any increase in the cost of managing these women and their pregnancies pales beside the clinical alternative.
"The cost of diagnosing and treating women with gestational diabetes is relatively little compared with other health costs. However, there are unfortunately a lot of potential add-on costs. We know that women with gestational diabetes have more interventions, both obstetric and pediatric."
Even considering those costs, ensuring the long-term health of these mothers and babies is a good investment, he said. To put the cost in perspective, "One course of experimental cancer therapy is likely to cost more than testing 1,000 women and treating the 130 with gestational diabetes. It is all a matter of perspective and priority."
He’s glad that Australia chose to move ahead with the change rather than wait for the official numbers to prove that it works.
"Large studies are difficult to initiate and fund. At some stage, common sense has to prevail. Waiting for the results of trials which will not happen in our lifetime should not be an excuse not to give the best possible maternal and fetal care. This is too important a problem to ignore, especially as the solution is relatively simple and the cost is relatively trivial," he said.