ONE STEP SCREENING AND DIAGNOSTIC TESTING FOR MATERNAL HYPERGLYCEMIA IN EARLY PREGNANCY USING 75G ORAL GLUCOSE TOLERANCE TEST
BAKGROUND: Hyperglycemia in pregnancy is associated with significant maternal and perinatal morbidity and mortality. Early Identification and treatment of the hyperglycemia in pregnancy is the goal for improving maternal and fetal outcome.
AIM: To determine the diagnostic performance of the 75g OGTT when done before the 24th week of pregnancy using the 75g OGTT done between 24-28 weeks as reference standard.
METHODS: This was a cross-sectional study carried on between 1st of December 2016 to 30th May 2017 in Federal Teaching Hospital Ido-Ekiti and Ekiti State University Teaching Hospital Ado-Ekiti. 280 pregnant women who satisfy the study inclusion criteria were selected using convenience sampling method and were screened with the 75g OGTT before 24 weeks of Pregnancy. The women who tested negative at this stage were screened again between 24-28 gestational weeks of pregnancy. The diagnostic performance of the 75g OGTT and its FPG component were determined by measuring their sensitivity, specificity, positive and negative predictive power.
RESULTS: A total of 280 women were screened for hyperglycemia in pregnancy using the 75gOGTT before 24weeks and between 24-28weeks. Ten participants were lost to follow up.
Five were screened positive with the 75g OGTT before 24weeks. The remaining 265 were screened negative for hyperglycemia before 24 weeks. The negative cases were rescreened between 24-28weeks using the 75gOGTT. Sixteen women were screened positive for hyperglycemia between 24-28weeks. There were 21 cases of hyperglycemia in pregnancy from this study. The prevalence of hyperglycemia in pregnancy was 7.8% while the prevalence when 75gOGTT was done before 24 weeks was 1.9%.
Sensitivity, specificity, and negative predictive value of the FPG component of the 75g OGTT were 80%, 100% and 20% respectively. The sensitivity, specificity and false negative rate of the 75gOGTT before 24 weeks using the 75gOGTT between 24-28weeks as reference were 23.8%, 100% and 76.2%. Five out of the 21 cases of hyperglycemia in pregnancy were detected before 24 weeks and represent the lost opportunity for early intervention when the screening and diagnosis of hyperglycemia was restricted to between 24-28weeks using the 75gOGTT.
CONCLUSION: Screening and diagnosis of hyperglycemia in early pregnancy is justified. This should however be done using the FPG while the 75gOGTT should be done between 24-28weeks for women who screened negative for hyperglycemia in early pregnancy.
KEY WORDS: Hyperglycemia in Pregnancy, Gestational Diabetes, Diabetes in Pregnancy, Overt Diabetes, diagnostic and screening tests.