Serum Fructosamine in Pregnancy
Abstract:
Introduction: American College of Obstetricians and Gynecologists (ACOG) and American Diabetes Association (ADA) recommend 2 step testing for diagnosis of Gestational Diabetes Mellitus (GDM). The process is cumbersome and inconvenient. Hemoglobin A1C (HbA1c) levels are adopted as a screening test in non-pregnant adults, but not during pregnancy. Alternatively, serum fructosamine is not tested for diagnosis of Diabetes Mellitus in any population. We are in the process of examining utility of serum fructosamine as a screening test for diagnosis of Gestational Diabetes Mellitus (GDM). However, no data is available regarding fructosamine concentrations in non-diabetic pregnant women. Therefore, we determined serum fructosamine levels in pregnant non-diabetic women at 24 to 28 weeks at the time of 1 hour or 3-hour oral glucose tolerance tests (OGTT).
Subjects and Methods: Random plasma glucose (mg/dl), serum fructosamine (mM/l) and HbA1c (%) were determined at 24-30 weeks in 200 pregnant women, age 24-40 years, in whom the diagnosis of GDM was eliminated by either normal 1 hour (OGTT) or by normal 3-hour OGTT in presence of abnormal 1-hour OGTT according to criteria established by ACOG and ADA. 25 age matched non-pregnant women participated as controls. Normal reference ranges for all determinations were established by the local laboratory (Random plasma glucose, 65-140; Serum fructosamine, 200-285; HbA1c, 4.8-5.6). Statistical comparisons between 2 groups were conducted using Student’s ‘t’ test.
Results: Serum fructosamine levels (182 ± 4) were significantly lower (p< 0.01) in non-diabetic pregnant women when compared with age matched non-pregnant women (224 ± 5). Cutoff fructosamine between groups was 198. Random plasma glucose (96 ±7) and HbA1c (5.1 ± 0.2) were not significantly different amongst groups.
Conclusion: In non-diabetic pregnant women, serum fructosamine concentrations are subnormal whereas random plasma glucose and HbA1c levels remain within normal range noted in age matched non-pregnant women. Further studies are underway to assess the utility of serum fructosamine as a screening test in diagnosis of GDM.
