Workineh Tamir
Background: Reference interval for electrolytes currently applicable for pregnant women in Ethiopia is used from other populations that are adopted from textbooks and literatures. However, using others` reference interval is might not useful for clinical decisions during pregnancy due to normal changes resulted from different hormonal changes that may affect biochemical parameters.
Objective: The aim of this study was to establish trimester based reference intervals for electrolytes among apparently healthy pregnant women at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia.
Methods: Institutional based cross-sectional study was applied and based on the selection criteria, 459 apparently healthy pregnant women were enrolled in this study. Finally, reference intervals were established by non-parametric methods by the recommendation of Clinical and Laboratory Standards Institute guideline C28-A3. The 95% reference interval was estimated by using 2.5th percentile for lower reference limit and 97.5th percentile upper reference limit. The Kruskal Wallis and Post-Hoc tests were applied to compare medians within trimesters and statistically significant difference between trimesters respectively.
Results: The 95% reference interval for biochemical parameters were: Na: 121.7-158.6, 121.85-153, 123.7-149.45, Ca: 1.89-3.25, 1.15-2.92, 1.63-2.97, K: 3.02-6.3, 3.06-6.27, 3.09-5.57, Cl: 94.85-136.9, 94.85-166, 91.55-122, for 1st, 2nd and 3rd trimesters respectively. Besides this, the statistical significant difference within and between trimesters was recorded for almost all parameters.
Conclusion: The reference interval for electrolytes determined in this study was different from the reported reference interval in literature and manufacturer provided as well. Thus, these newly established reference intervals of electrolytes will be valuable for the detection and monitoring of different complications related with pregnancy.