目的:探讨产前可疑Beckwith-Wiedemann综合征（Beckwith-Wiedemann syndrome, BWS）胎儿的遗传学检测，以提高该综合征的产前遗传学诊断率。方法:1例既往孕18周超声发现胎儿脐膨出、胎盘增厚引产孕妇，此次妊娠孕13周超声再次发现胎儿脐膨出、胎盘增厚。行绒毛活检取样术后，应用单核苷酸多态性微阵列（single nucleotide polymorphism array, SNP array）芯片对全基因组拷贝数变异分析，之后应用甲基化特异性多重连接探针扩增（methylation-specific multiplex ligation-dependent probe amplification, MS-MLPA）技术检测染色体11p15区域n H19和n KCNQ1基因的甲基化状态和拷贝数变化。同时采集胎儿父母外周血行染色体高分辨G显带核型分析和SNP array检测。n 结果:胎儿绒毛SNP array提示11p15.5区域有176 kb杂合缺失；MS-MLPA提示印记控制区域2甲基化缺失，n KCNQ1（L02903）基因拷贝数减少50%。胎儿父母的SNP array检测和染色体G显带核型分析均未发现异常。诊断该例胎儿为BWS。n 结论:孕早期超声发现胎儿脐膨出、胎盘异常增厚等宫内异常表现时，应选择相应的遗传学检测，建议产前诊断选择MS-MLPA和SNP array，避免漏诊BWS。“,”Objective:To investigate the prenatal genetic testing for suspected Beckwith-Wiedemann syndrome (BWS) to improve its prenatal diagnosis rate.Methods:This study reported a pregnant woman, who had a pregnant history of termination due to the same reason at 18 weeks, with fetal acromphalus and unusually thickened placenta indicated by ultrasound examination at 13 weeks of gestation. After chorionic villus sampling, single nucleotide polymorphism (SNP) array was used to analyze copy number variations in the whole genome, and methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) was also performed to detect the methylation and copy number variations in n H19 and n KCNQ1 genes on chromosome 11p15. Peripheral blood samples were collected from the couple for chromosome G-banding karyotype analysis and SNP array.n Results:The SNP array indicated a 176 kb heterozygous deletion in the 11p15.5 region. MS-MLPA revealed a loss of methylation at imprinting control region 2 and a 50% reduction of copy numbers of n KCNQ1 (L02903) gene. No abnormality was found in the parents in the SNP array and G-banding karyotype analysis. The fetus was prenatally diagnosed with BWS.n Conclusions:When intrauterine abnormalities, such as acromphalus and abnormal thickening of the placenta, are found by ultrasound during early pregnancy, prenatal genetic tests related to BWS, including MS-MLPA and SNP array, are suggested to avoid a missed diagnosis of BWS.