Since the beginning of this year, KK Women’s and Children’s Hospital (KKH) and Singapore General Hospital have been offering routine screening for gestational diabetes mellitus for all its pregnant patients at 24 to 28 weeks, as part of a six-month pilot project.

 

The women are screened with an oral glucose tolerance test (OGTT) using a flavoured sweet drink. Two blood samples are taken, one before they drink it and one after. The samples are then tested for the level of glucose in their blood. The screening, while routine, is not mandatory and is aimed at earlier detection and intervention.

 

Gestational diabetes mellitus is a condition in which the body does not produce enough of the hormone insulin to control sugar levels during pregnancy. This puts both mother and child at risk. The baby can have excessive weight gain, get hypoglycaemia after birth, develop fetal abnormalities, and even succumb to sudden fetal death. The mother can get high blood pressure and eclampsia while pregnant, give birth prematurely and run the risk of getting Type 2 diabetes in the future.

 

 

The test was offered at KKH after the hospital and Duke-NUS Medical School did a study comparing the benefits of the routine oral glucose tolerance test with targeted screening or no screening at all.

 

The researchers found that pregnant women benefit most from routine screening with the OGTT. It allows for timely intervention and brings about health benefits that far outweigh the cost. It is a more cost effective approach to reduce complications of the condition in Singapore, compared to targeted screening or no screening.

 

According to Professor Tan Kok Hian, Senior Consultant and Head, Perinatal Audit and Epidemiology Unit, Division of Obstetrics and Gynaecology, KKH, who led the study, a previous local study had shown that the previous practice of targeted screening (screening only high risk cases) failed to identify more than 25 per cent of mothers with gestational diabetes. Previously, only pregnant women over 35 years old, or those with a high body mass index, or those who have relatives with diabetes, were screened for this condition.

 

He said that even if there is no family history of diabetes, a pregnant woman can develop gestational diabetes mellitus. “With increasing gestation, blood sugar levels may rise. In most cases, the condition disappears after delivery, but in some women, it may persist and they will need long-term follow-up and treatment.” 

 

 

Prof Tan said screening is the most effective way to avoid under-diagnosing the condition, and to detect and manage it early. Pregnant women with the condition show no symptoms, although some may experience increased thirst, urination, appetite, and fatigue. Their raised blood sugar levels are likely to be discovered during a routine antenatal check-up with an OGTT.

 

Why some develop the condition is unclear although one local study found that Asians were more at risk of it than Caucasians. In Singapore, KKH sees about 12,000 births a year on average, and about 15 per cent of those pregnant women develop the condition.

 

Prof Tan said the condition is responsible for about 5 per cent of stillbirths in KKH. Such cases usually involve pregnant women with diabetes who were initially not seen at KKH and only went to the hospital later for delivery. Others were detected late because they either went to KKH in late pregnancy, or missed follow-ups and necessary medical interventions. Treatment includes dietary counselling or insulin treatment, depending on the severity of the condition.