Yeo G S, Tan K H, Liu T C
Maternal Fetal Medicine Department, Kandang Kerbau Hospital, Singapore.
Ann Acad Med Singap. 1994 May;23(3):363-6.
Both beta thalassaemia and HbE disease are microcytic red cell disorders. Pregnancy however induces macrocytosis which makes screening with the mean cell volume (MCV) difficult in antenatal patients. In addition, population screening for HbE has not been widely reported in the literature and the screening criteria for beta thalassaemia may not necessarily apply. A study of the value of the MCV for routine screening for both beta thalassaemia and HbE traits in 3696 antenatal patients of different gestational ages was carried out. All patients with an MCV < or = 80 fL received confirmatory tests for haemoglobinopathies. The MCV rose by only 2.0% in pregnancy. A total of 494 patients (13.4% of the general population) had an MCV < or = 80 fL. Of these microcytic patients, 11.3% (56) and 4.7% (23) were eventually confirmed to have beta thalassaemia and HbE traits respectively. The mean MCV for the 3696 antenatal patients was 87.8 fL (SD 7.5) compared to patients with beta thalassaemia and HbE traits, which were 67.5 fL (SD 4.5) and 75.7 fL (SD 4.1). HbE traits were less microcytic than beta thalassaemia traits and overlapped significantly with the general population. Beta thalassaemia trait and HbE trait detected by this screening method constituted 1.52% and 0.62% respectively of the total antenatal population screened. The MCV remains a valid screening parameter in pregnancy for beta thalassaemia trait. As for HbE trait, applying a discriminant value of 80 fL to the MCV in the population screening would miss a significant proportion of the HbE traits.(ABSTRACT TRUNCATED AT 250 WORDS)
β地中海贫血和血红蛋白E病均为小红细胞性疾病。然而，妊娠会导致大红细胞症，这使得在产前患者中利用平均红细胞体积（MCV）进行筛查变得困难。此外，关于血红蛋白E病的群体筛查在文献中尚未广泛报道，且β地中海贫血的筛查标准未必适用。对3696例不同孕周的产前患者进行了一项关于MCV在β地中海贫血和血红蛋白E病特征常规筛查中的价值的研究。所有MCV≤80 fL的患者均接受了血红蛋白病的确诊检查。妊娠期间MCV仅升高2.0%。共有494例患者（占总人群的13.4%）的MCV≤80 fL。在这些小红细胞性患者中，最终分别有11.3%（56例）和4.7%（23例）被确诊为β地中海贫血特征和血红蛋白E病特征。3696例产前患者的平均MCV为87.8 fL（标准差7.5），而β地中海贫血特征和血红蛋白E病特征患者的平均MCV分别为67.5 fL（标准差4.5）和75.7 fL（标准差4.1）。血红蛋白E病特征的小红细胞程度低于β地中海贫血特征，且与总人群有显著重叠。通过这种筛查方法检测到的β地中海贫血特征和血红蛋白E病特征分别占所筛查的产前总人群的1.52%和0.62%。MCV在妊娠期间仍是β地中海贫血特征的有效筛查参数。至于血红蛋白E病特征，在群体筛查中将80 fL的判别值应用于MCV会遗漏相当一部分血红蛋白E病特征。（摘要截短于250字）
