Feuchtbaum L B, Cunningham G, Waller D K, Lustig L S, Tompkinson D G, Hook E B
Genetic Disease Branch, California Department of Health Services, Berkeley, USA.
Obstet Gynecol. 1995 Aug;86(2):248-54. doi: 10.1016/0029-7844(95)00155-k.
To study the chromosome abnormality rate among women with elevated levels of maternal serum alpha-fetoprotein (MSAFP) and the types of chromosome abnormalities in this population, and to compare this rate with reports in the literature and the rate observed in the general population.
We studied 8097 women who chose to undergo amniocentesis and fetal karyotyping after having an elevated MSAFP test of 2.5 multiples of the median (MOM) or higher. All abnormal karyotypes were reviewed and grouped according to whether the elevated MSAFP value could be explained by a ventral wall or neural tube defect.
The overall chromosome abnormality rate was 13.83 per 1000 amniocenteses. The rate in the "unexplained" group was 10.92 per 1000 amniocenteses. Just over half (53%) of the abnormal karyotypes were autosomal anomalies, and 47% were sex chromosome abnormalities. The autosomal aneuploidies observed most frequently were triploidy and trisomy 13. The sex chromosome abnormalities observed most frequently were the XXY and XYY karyotypes.
Women who have unexplained elevated MSAFP values of 2.5 MOM or greater have a twofold increase in the rate of chromosome abnormalities in their fetuses compared with the general population (P < or = .001). This rate is consistent with other studies that used a 2.5 MOM cutoff. Studies that used a 2.0 MOM cutoff have reported chromosome abnormality rates that do not vary from general population estimates.
研究母血清甲胎蛋白（MSAFP）水平升高的女性的染色体异常率以及该人群中染色体异常的类型，并将此率与文献报道及一般人群中观察到的率进行比较。
我们研究了8097名女性，她们在MSAFP检测值高于中位数的2.5倍（MOM）或更高后选择接受羊膜穿刺术和胎儿核型分析。所有异常核型均根据MSAFP升高值是否可由腹壁或神经管缺陷解释进行审查和分组。
每1000例羊膜穿刺术的总体染色体异常率为13.83。“无法解释”组中每1000例羊膜穿刺术的发生率为10.92。略超过一半（53%）的异常核型为常染色体异常，47%为性染色体异常。最常观察到的常染色体非整倍体是三倍体和13三体。最常观察到的性染色体异常是XXY和XYY核型。
与一般人群相比，MSAFP值在2.5MOM或更高且无法解释地升高的女性，其胎儿染色体异常率增加两倍（P≤0.001）。该率与其他使用2.5MOM临界值的研究一致。使用2.0MOM临界值的研究报告的染色体异常率与一般人群估计值无差异。
