Detection of β_2-microglobulin reference ranges in fetal blood and amniotic fluid

Objective:To investigate the reference ranges of β_2-microglobulin in the fetal blood and amniotic fluid.Methods: β_2-microglobulin were determined from 81 fetal blood samples of 19-38 weeks gestation.And 121 fetal amniotic fluid samples of 15-38 weeks gestation.;Pure fetal blood was obtained by cordocentesis under continuous ultrasound guidance.Results: During 15-18 weeks′ gestation,fetal β_2-MG are 10.5± 3.6 in the amniotic fliud,19-22 weeks′ gestation,fetal β_2-MG are 12.2± 4.2 in the amniotic fluid and 4.85±0.58in the serum,23-26 weeks′ gestation,fetal β_2-MG are 12.1± 4.1 in the amniotic fluid and 4.76±0.55 in the serum,27-30 weeks′ gestation,fetal β_2-MG are 10.5± 2.7 in the amniotic fluid and 4.8±0.59 in the serum,31-34 weeks′ gestation,fetal β_2-MG are 5.1± 1.9 in the amniotic fluid and 4.1±0.62 in the serum,35-38 weeks′ gestation,fetal β_2-MG are 12.2± 4.2 in the amniotic fluid and 4.85±0.62 in the serum.Conclusion:β_2-microglobulin are decrease with gestation age.(P0.05),All information will improve our knowledge of fetal medicine and be useful in evaluation of fetal kidney′s funtion.