Adverse Pregnancy Outcomes Among Pregnant Women With Abnormal Versus Normal Glucose Challenge Test Managed at the Kenyatta National Hospital Between 2018 and 2019 (a Retrospective Cohort Study)

Abstract

Background: Gestational diabetes mellitus (GDM) refers to glucose intolerance of any degree, with first recognition or onset during pregnancy. Globally, hyperglycemia afflicts around16% of all live births, 85% of the cases being gestational diabetes mellitus (GDM). In sub–Saharan Africa (SSA), GDM afflicts about 14% of pregnancies. In Kenyatta National Hospital, the prevalence of GDM 23 %. The documented adverse pregnancy outcomes associated with gestational diabetes include increased risk of primary caesarian sections (CS), shoulder dystocia, pre-eclampsia and large for gestational age (LGA). However, the outcomes of pregnancies complicated with abnormal glucose challenge test have not been reported in this setting. Objective: To evaluate adverse maternal and perinatal pregnancy outcomes (immediate and at 2 years of follow up) of pregnant women with abnormal versus normal glucose challenge test performed between December 2018 and April 2019 at the Kenyatta National Hospital. Methodology: In this retrospective cohort study, records of Kenyan women who underwent glucose challenge and tolerance test at Kenyatta National Hospital between 24-28 weeks of pregnancy for the period December 2018 and April 2019 were abstracted to evaluate the pregnancy outcomes. Data analysis: Data was exported into STATA version 12 for cleaning and analysis. Duplicity of data was checked and removed. Inaccuracies were corrected and pairwise deletion used to handle missing data. Categorical biodata was summarized using frequencies and presented in charts and tables. Continuous biodata was summarized using means. The incidence of adverse fetal and maternal outcomes among women with abnormal glucose test results was calculated by dividing the total number of adverse outcomes by the number of mothers who got the test results and 95% confidence interval estimates calculated using the Exact Clopper Pearson method. Maternal and perinatal outcomes of women who had normal and abnormal glucose challenge tests were compared using Chi square test at 95% confidence interval (CI) and relative risks (RR) interpreted as the measure of association. Multivariable analysis using Cox regression with robust variance was used to control confounding factors which included age, marital status, and employment status. P value of less than 0.05 was statistically significant. Results: Data was retrieved from 438 women and 142 were determined as eligible. Of these 71 mothers had abnormal and 71 had normal GCT. Mothers with abnormal compared to normal GCT were more likely to be older (32.7±5.5 versus 30.1±5.9 years, p = 0.016), and married (95.8% versus 85.9%, p = 0.042), employed (90.1% versus 71.8%, p = 0.005). After adjusting for age, marital status, and employment, having abnormal GCT compared to normal GCT was associated with higher risk of diabetes (adjusted RR (2.26) (95% CI=1.21-4.19), p = 0.010), delivery complications (adjusted RR (2.21) (95% CI=1.21- 4.06), p = 0.010), macrosomia (adjusted RR (1.99) (95% CI=1.02- 3.90), p = 0.043) and newborn unit admission (adjusted RR (1.92) (95% CI=1.06-3.47), p = 0.031). 26.3% had abnormal GCT and OGTT. 73.2% had abnormal GCT alone. After adjusting for age, marital and employment status, abnormal GCT and OGTT compared to abnormal GCT alone was associated with a higher risk of elevated pressure in pregnancy (adjusted RR (3.51) (95% CI=1.15-10.8), p = 0.028), delivery complications (adjusted RR (3.53) (95% CI=1.23-10.1), p = 0.019), macrosomia (adjusted RR (2.88) (95% CI=1.06- 7.83), p <0.001) and newborn unit admission (adjusted RR 3.18) (95% CI=1.09-9.27), p <0.001. Only 25% underwent blood sugar evaluation and monitoring post-partum at six weeks. Conclusions: Women with abnormal GCT compared to normal GCT had higher incidence of adverse maternal and perinatal outcomes including diabetes in pregnancy, macrosomia, newborn unit admission, and maternal complications after delivery compared to those who had normal GCT. Also, postpartum women who had abnormal GCT and OGTT had higher risk of adverse outcomes compared to those who had abnormal GCT alone. Women with abnormal GCT/OGTT have lower rates of universal testing for diabetes after delivery.