Liver function tests in pre-eclampsia: importance of comparison with a reference range derived for normal pregnancy

Area of Science:

• Obstetrics and Gynecology
• Clinical Biochemistry
• Maternal-Fetal Medicine

Background:

• Standard laboratory reference ranges for liver function tests (LFTs) may not accurately reflect physiological changes during pregnancy.
• Establishing pregnancy-specific reference ranges is crucial for accurate diagnosis and management of liver-related complications in pregnant individuals.

Purpose of the Study:

• To determine reference ranges for key liver function tests (LFTs) in uncomplicated pregnancies.
• To assess the utility of these pregnancy-derived LFT ranges in identifying abnormalities and their correlation with outcomes in pre-eclampsia.

Main Methods:

• A prospective, cross-sectional study was conducted to establish reference ranges for aspartate transaminase (AST), alanine transaminase (ALT), bilirubin, and gamma glutamyl transferase (GGT) in 430 women with uncomplicated pregnancies.
• A prospective observational study of 85 women with gestational hypertension/pre-eclampsia was performed to relate abnormal LFTs to maternal and fetal outcomes.

Main Results:

• Liver function tests (AST, ALT, bilirubin, GGT) were found to be lower in uncomplicated pregnancy compared to standard nonpregnant laboratory reference ranges.
• Using pregnancy-derived ranges, 37% of pre-eclampsia cases showed LFT abnormalities not detected by standard ranges.
• Elevated LFTs in pre-eclampsia were significantly associated with increased proteinuria, lower platelet counts, and more maternal complications.

Conclusions:

• Current standard reference ranges for LFTs are inappropriate for pregnant populations.
• Pregnancy-derived reference ranges for LFTs enhance the precision in identifying abnormal liver function in pre-eclampsia.
• Utilizing these new ranges aids in better risk stratification and management of pre-eclampsia.