Changes of serum homocysteine levels during pregnancy and the establishment of reference intervals in pregnant Chinese women

Reference intervals (RIs) of clinical laboratory indexes are important basis for interpretation of corresponding test results. While elevated homocysteine (HCY) level is a risk factor of some severe gestational diseases, HCY RIs for pregnant women have not been reported so far. The current use of HCY RIs established for general population in pregnant women may challenge clinicians' judgment. This study aims to investigate the changes of serum HCY levels during pregnancy and establish the RIs of serum HCY in healthy pregnant Chinese women to provide valuable data to clinicians and enable the provision of more appropriate therapy. 354 healthy pregnant Chinese women were randomly selected and divided into three groups according to gestational age: 114 in first trimester (1–13 week), 120 in second trimester (14–27 week) and 120 in third trimester (≥28 week). 120 healthy non-pregnant Chinese women were randomly selected as the non-pregnant control group. Serum HCY levels were determined on automatic biochemical analyzer with enzymatic cycling method. The RIs of serum HCY for healthy pregnant women were established using a nonparametric method. the RIs of serum HCY for healthy pregnant women is 5.79–11.86 μmol/L in first and second trimester (combined) and 6.13–16.75 μmol/L in third trimester. Besides, the RIs of serum HCY for healthy non-pregnant women is 8.25–22.92 μmol/L. Rigorously according to CLSI C28-A3 guidelines, the authoritative document of RIs establishment, the RIs of serum HCY for healthy pregnant Chinese women were established, which will provide a valuable reference for clinical work and laboratory researches. •The RIs of HCY for healthy pregnant Chinese women is 5.79–11.86 μmol/L in first and second trimester.•The RIs of HCY for healthy pregnant women is 6.13–16.75 μmol/L in third trimester.•The RIs of HCY for healthy non-pregnant women is 8.25–22.92 μmol/L.•HCY level is lower in healthy pregnant women than in non-pregnant women.•From first and second trimester to third trimester, serum HCY levels bounce back.