Abstract
Background: Gestational diabetes mellitus (GDM) is a type of insulin resistance that develops in the second trimester of pregnancy. This type of diabetes ends after delivery. GDM poses serious health hazards to both the mother and the baby. Pathology behind this carbohydrate intolerance is insulin resistance. The previous studies have pointed out that this insulin resistance is due to oxidative stress caused by free radicals. Free radicals can be generated by iron. Since pregnancy is a condition where iron requirement rises, universal iron supplementation is given. According to the previous studies, excess iron can cause free-radical mediated injury leading on to diabetes. Supplementation of a prooxidant irrespective of body iron stores may be more harmful than beneficial. Hemoglobin and PCV are two hematological parameters that reflect body iron stores.

Aims and Objectives: The aim of the study was to compare hemoglobin and PCV values in pregnant woman with and without GDM.

Materials and Methods: A case–control study was done in the obstetric department of a tertiary care center in south India from August 2010 to December 2010.The study included 85 cases and 85 controls. Cases were pregnant women at 24–28 weeks of gestation with gestational diabetes who attended the obstetric OPD during the study period. GDM was diagnosed as per ADA guidelines. Controls were pregnant women at 24–28 weeks gestation without GDM as per ADA guidelines. Data for the study were collected using a preformed tested questionnaire. All subjects were provided with iron supplementation according to the national programme. Estimation of hemoglobin and PCV was done with 2 ml of blood sample obtained by venepuncture using an automated analyzer. The association of elevated hemoglobin and PCV with the risk of developing GDM was tested using Chi-square analysis. P ≤ 0.05 was taken as statistically significant.

Results: Hemoglobin in cases and controls showed a significant difference by Chi-square analysis (P = 0.004). PCV in cases was significantly higher than in controls by Chi-square analysis (P = 0.003).

Conclusion: The study found a statistically significant association between higher maternal hemoglobin level and PCV with GDM.

Key words: Gestational Diabetes Mellitus; Hemoglobin; PCV; Free Radicals; Oxidative Stress; Iron Supplementation