Harris Birthright Research Centre for Fetal Medicine, King's College Hospital Medical School, London, UK.
Ultrasound Obstet Gynecol. 2010 Sep;36(3):291-5. doi: 10.1002/uog.7717.
To determine the need for fetal karyotyping in cases of an isolated single umbilical artery (SUA) identified during the second-trimester routine anomaly scan.
All patients booked for antenatal care and delivery in our hospital are offered two ultrasound scans in pregnancy, one at 11-13 weeks' gestation as part of screening for chromosomal defects and another at 20-23 weeks for detailed fetal examination. In addition we examine patients referred from other hospitals because of suspected fetal abnormalities during their routine second-trimester scan. We performed a search of the database to retrieve all cases with an SUA and reviewed the ultrasound findings, fetal karyotype and pregnancy outcome.
There were 643 cases with SUA, including 424 (65.9%) where the condition was isolated, 133 (20.7%) with one major fetal defect and 86 (13.4%) with multiple defects. The incidence of chromosomal abnormalities was 0% in the isolated SUA group, 3.7% in those with one defect and 50.7% in those with multiple defects. The commonest chromosomal abnormalities were trisomy 18, trisomy 13 and triploidy, which together accounted for 82.9% of cases.
The finding of an SUA should prompt the sonographer to search for fetal defects and if these are found the risk for chromosomal abnormalities is increased. In cases of apparently isolated SUA there is no evidence of increased risk of chromosomal abnormalities.
确定在妊娠中期常规异常扫描中发现孤立性单脐动脉（SUA）时是否需要进行胎儿染色体核型分析。
我们医院所有预约产前保健和分娩的患者均在妊娠期间接受两次超声检查，一次在 11-13 孕周进行，作为染色体缺陷筛查的一部分，另一次在 20-23 孕周进行详细的胎儿检查。此外，我们还检查了因在常规妊娠中期扫描中怀疑胎儿异常而从其他医院转来的患者。我们对数据库进行了检索，以检索所有具有 SUA 的病例，并回顾了超声检查结果、胎儿染色体核型和妊娠结局。
共有 643 例 SUA，其中 424 例（65.9%）为单纯性 SUA，133 例（20.7%）有 1 种主要胎儿缺陷，86 例（13.4%）有多种缺陷。单纯性 SUA 组的染色体异常发生率为 0%，1 种缺陷组为 3.7%，多种缺陷组为 50.7%。最常见的染色体异常是三体 18、三体 13 和三倍体，它们共占病例的 82.9%。
发现 SUA 应促使超声医师寻找胎儿缺陷，如果发现这些缺陷，染色体异常的风险就会增加。在单纯性 SUA 的情况下，没有证据表明染色体异常的风险增加。
