Haddow J E, Kloza E M, Smith D E, Knight G J
Obstet Gynecol. 1983 Nov;62(5):556-60.
In Maine, maternal serum alpha-fetoprotein (AFP) values equaled 2 or more multiples of the median in 4.8% of screened women. Between 2.0 and 2.9 multiples of the median repeat maternal serum AFP testing and sonography were comparable as the next diagnostic step; at 3 multiples of the median or higher sonography was superior. Sonography moved dates back in only ten singleton viable pregnancies with maternal serum AFP elevations; three of these had open fetal defects. Among singletons, all five anencephaly cases, one of two open spina bifida lesions, and all three open ventral wall defects were identified. Three closed singleton neural tube defects and two open spina bifida defects in twins were not detected. Nineteen of 36 multiple gestations had maternal serum AFP 2 or higher multiples of the median. In singletons, maternal serum AFP of 3 or higher multiples of the median indicated a thirtyfold increased risk for fetal death and a sevenfold increased risk for birth weight under 2500 g.
在缅因州，4.8%接受筛查的孕妇血清甲胎蛋白（AFP）值等于或超过中位数的2倍。在中位数的2.0至2.9倍之间，重复进行孕妇血清AFP检测和超声检查作为下一步诊断措施的效果相当；在中位数的3倍或更高时，超声检查更具优势。超声检查仅在10例单胎活产且孕妇血清AFP升高的妊娠中使孕周提前；其中3例存在开放性胎儿缺陷。在单胎妊娠中，所有5例无脑儿病例、2例开放性脊柱裂病变中的1例以及所有3例开放性腹壁缺陷均被检出。3例闭合性单胎神经管缺陷和2例双胎开放性脊柱裂缺陷未被检测到。36例多胎妊娠中有19例孕妇血清AFP为中位数的2倍或更高。在单胎妊娠中，孕妇血清AFP为中位数的3倍或更高表明胎儿死亡风险增加30倍，出生体重低于2500g的风险增加7倍。
