Reference intervals are essential for clinical decision-making in clinical chemistry, as they provide a basis for interpreting laboratory results during diagnosis, treatment, and patient monitoring. These intervals vary across populations due to differences in ethnicity, age, gender, and analytical methods. Additionally, pregnancy introduces significant hormonal changes that can alter clinical chemistry parameters, including lipid profiles. Therefore, this study aimed to establish trimester-specific reference intervals for lipid profile parameters among healthy pregnant women at Debre Markos Comprehensive Specialized Hospital in Northwest Ethiopia. An institution-based cross-sectional study was conducted from February 1, 2022, to May 30, 2023, among 459 apparently healthy pregnant women who met the inclusion criteria. Reference intervals were established using nonparametric statistical methods in accordance with the Clinical and Laboratory Standards Institute guideline C28-A3. The 95% reference intervals were determined using the 2.5th percentile as the lower reference limit and the 97.5th percentile as the upper reference limit. The 95% reference interval for lipid parameters was: Total cholesterol: 106-351, 119-375.6, and 110-389.5 mg/dL, Triglycerides: 54-339, 60-292, and 67-334.3 mg/dL, High density lipoprotein cholesterol: 16.7-89.3, 24-99.15, and 19.85-101.15 mg/dL, Low density lipoprotein cholesterol: 32.95-194.3, 54.25-192.95, and 59.95-199 mg/dL, for the 1st, 2nd, and 3rd trimesters respectively. Statistically significant differences were observed both within and between trimesters for nearly all lipid parameters. Furthermore, the trimester-specific reference intervals established in this study differed from the manufacturer-provided reference intervals for the lipid profile tests. The reference intervals previously in use did not align with the trimester-specific intervals established in this study. All lipid profile parameters showed distinct reference ranges across the three trimesters. These findings underscore the need for locally derived, trimester-specific reference interval guidelines rather than reliance on broad, non-specific ranges.
Tamir et al. (Sat,) studied this question.