Barlow R D, Cuckle H S, Wald N J, Rodeck C H
Br J Obstet Gynaecol. 1982 Oct;89(10):821-6. doi: 10.1111/j.1471-0528.1982.tb05033.x.
The effect of blood contamination on the gel-acetylcholinesterase (AChE) test used in the diagnosis of fetal open neural-tube defects was studied with amniotic fluid samples artificially contaminated with fetal or maternal blood in concentrations covering a range exceeding that usually found in clinical practice. Amniotic fluid samples contaminated with maternal blood gave negative gel-AChE results at all concentrations. Contamination with fetal blood yielded positive results if the erythrocyte concentration was greater than about 60 x 10(6) cells/ml. Thus contamination of amniotic fluid with blood is only likely to cause false positive gel-AChE results if this critical concentration is exceeded. Such samples will occur only rarely in clinical practice but when they do the diagnosis should be made with caution.
采用浓度超过临床常见范围的胎儿或母体血液人工污染羊水样本，研究了血液污染对用于诊断胎儿开放性神经管缺陷的凝胶 - 乙酰胆碱酯酶（AChE）检测的影响。所有浓度的母体血液污染羊水样本的凝胶 - AChE检测结果均为阴性。如果红细胞浓度大于约60×10⁶个细胞/毫升，胎儿血液污染会产生阳性结果。因此，只有超过这一临界浓度，羊水被血液污染才可能导致凝胶 - AChE检测出现假阳性结果。此类样本在临床实践中很少出现，但一旦出现，诊断时应谨慎。
