目的 分析5例等臂双着丝粒Y染色体[idic(Y)]胎儿的产前诊断、遗传咨询与随访结果，为idic(Y)胎儿的临床处理提供参考依据。方法 选择2018年1月至2022年8月7 347例有产前诊断指征的孕妇，采用常规G显带核型及染色体微阵列分析（CMA）技术检测胎儿羊水，并用荧光原位杂交（FISH）技术验证，亲代染色体核型溯源检测。遗传咨询后跟踪随访妊娠结局。结果 共诊断新发的idic(Y)胎儿5例，其中例1胎儿为单纯的idic(Yq)，例2~5均为idic(Yq)与X单体的嵌合体。产前超声提示5例胎儿均为男性，除例1胎儿伴双侧马蹄内翻足可能外，其余4例均未见明显结构畸形。结合超声结果并予以个性化咨询后，例1~2选择继续妊娠，例3~5均终止妊娠。随访例1患儿至4周岁，足内翻手术效果良好，轻度发育迟缓经康复训练后好转；随访例2患儿至2周岁，暂未见异常表型；例3已再次受孕并分娩1名健康女婴；例4~5仍在备孕中。结论 细胞与分子遗传学技术的联合应用有助于产前诊断idic(Y)胎儿，合理的遗传咨询及长期随访可为其后续的临床诊疗提供重要依据。

Objective To analyze prenatal diagnosis, genetic counseling and follow-up of five fetuses with isodicentric Y chromosomes and to provide reference for the clinical treatment. Methods From January 2018 to August 2022, 7 347 pregnant women with prenatal diagnostic indications were selected, and fetal amniotic fluid was detected by conventional G-banding karyotype and chromosomal microarray analysis (CMA) simultaneously, and then verified by fluorescence in situ hybridization (FISH). Subsequently, parental karyotypes were analyzed. After genetic counseling, pregnant outcomes were followed up. Results Five fetuses with de novo idic(Y) were detected and all of these Y chromosomes had the same breakpoint in Yq11.2. Among them, four fetuses (cases 2~5) presented with a mosaic 45, X karyotype except the fetus of case 1. Prenatal ultrasonography indicated that all five fetuses were male and no obvious structural abnormalities were found in the other four fetuses except for case 1 with possible bilateral clubfeet. After personalized genetic counseling combined with the ultrasonography results, cases 1~2 chose to continue the pregnancy while cases 3~5 terminated the pregnancy. The child of case 1 was followed up to four years old. The surgical effect of strephenopodia was good, and the mild developmental retardation was improved after rehabilitation training. The child of case 2 was followed up to 2 years old, and no abnormal phenotype was found yet. Case 3 had been pregnant again and had given birth to a healthy baby girl while cases 4 and 5 were still in preparation for pregnancy. Conclusions The combined application of cellular and molecular genetic techniques is helpful for the prenatal diagnosis of the fetuses with idic(Y). Reasonable genetic counseling and long-term follow-up can provide an important reference for subsequent clinical diagnosis and treatment.