|ISSN No. 1606-7754 Vol.14 No.1 April 2006|
An evaluation of the latest ADA criteria for screening and diagnosing gestational diabetes at a tertiary care hospital in the United Arab Emirates
Laila O. Abdel-Wareth1, Aruna S. Kumari2, Afrozul Haq1, Ali Bakir3, Arifa Sainudeen4, Mohamed R. Sedaghatian,4 Susan John1, M. Moshaddeque Hossain5
Departments of 1Laboratory Medicine, 2Obstetric and Gynecology,3Internal Medicine,4 Neonatal Intensive Care, Mafraq Hospital, Abu- Dhabi, and Research Department, 5General Authority for Health Services, Abu Dhabi, United Arab Emirates.
The American Diabetic Association (ADA) has recently recommended lowering the cut-off values for the two-step oral glucose tolerance test (OGTT) used for screening of gestational diabetes. This study reports on the appropriateness of applying the latest ADA diagnostic criteria when screening for gestational diabetes mellitus (GDM) in a tertiary care facility in the United Arab Emirates. The study was carried out at Mafraq Hospital, Abu Dhabi, United Arab Emirates (UAE) between November 1999 and April 2001. A total of 889 pregnant women who underwent at least one test of the two-step OGTT were studied retrospectively for adverse maternal and fetal outcomes. Subjects were classified as GDM positive or negative by applying the old and the latest ADA criteria and the occurrence of adverse outcomes in the various groups was compared. Applying the latest ADA criteria with the two-step OGTT identified 11% & 17% more patients at risk for fetal and maternal adverse outcomes respectively. Advanced maternal age (> 30 years in our population), multi-parity (> 4) and obesity (BMI > 30) were associated with increased risk of being diagnosed as having GDM. Application of the latest ADA criteria to the two-step OGTT was determined to be appropriate for UAE pregnant women tested for GDM in the tertiary care setting. Older (age > 30 years ), multiparous ( parity > 4), and obese women ( BMI > 30 ) were at greater risk of GDM diagnosis by the latest ADA criteria. (Int J Diabetes Metab 14: 55-60, 2006)
Key Words: American Diabetic Association, gestational diabetes mellitus, glucose load test, oral glucose tolerance test.
Gestational diabetes mellitus (GDM) is defined as glucose intolerance first recognized during pregnancy.1 The prevalence ranges from 1-14% of all pregnancies depending on the population studied and the diagnostic test employed.2 If left untreated GDM may lead to severe neonatal and maternal complications such as still birth, fetal macrosomia, pre-eclampsia, and increased incidence of caesarean section.3-7 Early recognition and appropriate management of GDM by dietary modifications, insulin administration, and antenatal fetal surveillance can reduce these complications.5-8 Currently there are two strategies for screening for GDM. The first strategy - adopted by the American Diabetes Association (ADA) and the National Diabetes Data Group (NDDG) - consists of a 50g glucose load screening test (GLT) followed, among those positive in the screening test, by a 100g 3 hour oral glucose tolerance test (OGTT).9-12 The second strategy is the WHO one step 75g 2 hour OGTT.13,14
Mafraq Hospital is a 500 bed tertiary referral hospital in the Emirate of Abu Dhabi, United Arab Emirates (UAE) with annual deliveries of 2500 babies. At Mafraq Hospital, the two step approach to GDM screening is offered to non-diabetic pregnant women. Recently the ADA recommended lower cutoff values for both the 50g GLT, from 7.8 mmol/l to 7.2 mmol/l, and the 100g OGTT, from 5.8 (fasting), 10.5 (1 h), 9.2 (2 h) and 8.0 (3 h) mmol/l to 5.3, 10.0, 8.6 and 7.8 mmol/l respectively.15,16 Lowering the cut-off values has been reported to identify a greater number of pregnancies with GDM.17,18 However, this should be weighed against the financial implications of falsely labeling a patient as GDM positive.
In the Arabian Gulf Countries diabetes mellitus is considered to be a huge public health problem. A recent national epidemiological study in Saudi Arabia revealed DM prevalence of 23.7%.19 UAE is a multi-ethnic community with very high prevalence of GDM, obesity and multiparity.20,21 Therefore, applying the latest ADA criteria might be justified. However, optimum cut-off values for the GLT and the OGTT to be used in this population have not been defined.
This study reports on the appropriateness of applying the latest ADA diagnostic criteria for screening of GDM using the two step approach in pregnant women seen at tertiary care facility in the UAE.