Weiss R R, Macri J N, Elligers K, Princler G L, McIntire R, Waldman T A
Obstet Gynecol. 1976 Feb;47(2):148-51.
The prenatal diagnosis of anencephaly and spina bifida (neural tube defect, NTD) through amniotic fluid analysis for alpha-fetoprotein (AFP) is gradually gaining clinical recognition. AFP concentrations were determined in 237 amniotic fluids from normal pregnancies ranging between 7 and 42 weeks of gestation. A steady decline in AFP from 26 mug/ml at 7-9 weeks to 155 ng/ml at term is observed. AFP concentration was determined in 35 amniotic fluids from 33 confirmed neural tube defective pregnancies. In 14 cases where amniotic fluid was examined prior to the 26th week of gestation. AFP was markedly elevated when compared with the normal range of the same gestational period. In 21 amniotic fluids past the 26th week, 17 cases (85-) had markedly elevated AFP levels; however, 2 cases of anencephaly, 1 of spina bifida, and 1 of hydrocephaly gave levels within the normal range. It is concluded that elevated AFP in the amniotic fluid is a reliable but nonspecific marker for open neural tube defects prior to the 26th week of pregnancy, but may become normal after the 26th week in a small percentage of patients.
通过羊水甲胎蛋白（AFP）分析对无脑儿和脊柱裂（神经管缺陷，NTD）进行产前诊断正逐渐获得临床认可。对237例妊娠7至42周正常孕妇的羊水测定了AFP浓度。观察到AFP从妊娠7至9周时的26μg/ml稳步下降至足月时的155ng/ml。对33例确诊为神经管缺陷妊娠的35例羊水测定了AFP浓度。在妊娠26周前检查羊水的14例中，与相同孕周的正常范围相比，AFP明显升高。在26周后的21例羊水中，17例（85%）AFP水平明显升高；然而，2例无脑儿、1例脊柱裂和1例脑积水患者的AFP水平在正常范围内。结论是，妊娠26周前羊水中AFP升高是开放性神经管缺陷的可靠但非特异性标志物，但在一小部分患者中妊娠26周后可能变为正常。
