Screening for Gestational Diabetes Mellitus: Is There a Need for Early Screening for All Women in Developing Countries?

Background: Gestational diabetes mellitus (GDM) is associated with significant adverse pregnancy outcomes. Early diagnosis and treatment have been proven to reduce adverse pregnancy outcomes among women diagnosed with GDM. Current guidelines recommend routine screening for GDM at 24-28 weeks of pregnancy, with early screening offered to those considered high risk. However, risk stratification may not always be helpful for those who would benefit from early screening, especially in non-Western settings.

Aim: To determine the need for early screening for GDM among pregnant women attending antenatal clinics in two tertiary hospitals in Nigeria.

Methods: We conducted a cross-sectional study from December 2016 to May 2017. We identified women who presented at the antenatal clinics of the Federal Teaching Hospital Ido-Ekiti and Ekiti State University Teaching Hospital, Ado Ekiti. A total of 270 women who fulfilled the study inclusion criteria were enrolled. The 75 g oral glucose tolerance test was used to screen participants for GDM before 24 weeks and between 24 and 28 weeks for those who screened negative before 24 weeks. Pearson's chi-square test, Fisher's exact test, independent t-test, and Mann-Whitney U test were utilized in the final analysis.

Results: The median age of the women in the study was 30 (interquartile range: 27-32) years. Of our study participants, 40 (14.8%) were obese, 27 (10%) had a history of diabetes mellitus in a first-degree relative, and three (1.1%) women had a previous history of GDM. Twenty-one women (7.8%) were diagnosed with GDM, and six (28.6%) were diagnosed before 24 weeks. Women diagnosed with GDM before 24 weeks were older (37 years; interquartile range: 34-37) and more likely to be obese (80.0%). A significant number of these women also had identifiable risk factors for GDM: previous GDM (20.0%), family history of diabetes mellitus in a first-degree relative (80.0%), prior delivery of fetal macrosomia (60.0%), and previous history of congenital fetal anomaly (20.0%).

Conclusion:  The findings from the present study did not justify universal screening for GDM in all pregnant women. Patients diagnosed before the 24-28 weeks of universal screening are more likely to have significant risk factors for GDM and, therefore, would have been selected for screening based on the risk factor screening.