Bethune M
Ultrasound Department, The Royal Women's Hospital, Victoria, Australia.
Australas Radiol. 2007 Aug;51(4):324-9. doi: 10.1111/j.1440-1673.2007.01716.x.
Echogenic intracardiac focus and choroid plexus cysts are common findings at the midtrimester ultrasound. These findings have been linked with an increased risk of Down syndrome and trisomy 18. Most fetuses with these findings will, however, not have chromosomal abnormalities, especially when these findings are isolated. Patients experience considerable anxiety when informed of these findings and require extensive counselling in order to minimize anxiety not only about aneuploidy but also about the structure and development of the heart and brain. Although early studies showed an association with aneuploidies, several recent studies have cast doubt on this association. Many of the early studies were carried out in high-risk populations or in populations that had not had the benefit of other screening tests. Many Australian and New Zealand patients will access screening tests designed to detect these aneuploidies before presenting for a midtrimester ultrasound. Patients who have been screened by nuchal translucency, maternal serum screening or some combination of the two will already have had most cases of Down syndrome and trisomy 18 detected, and any soft marker found will almost certainly be a false positive. It is time to rethink the management of these markers. Recent evidence indicates that if these markers are found in isolation in an otherwise low-risk pregnancy, then there is minimal or no increase in the risk of Down syndrome or trisomy 18: these markers should be considered normal variants. The Australian Association of Obstetrical and Gynaecological Ultrasonologists consensus statement on these markers is included.
心内强回声光斑和脉络丛囊肿是孕中期超声检查的常见发现。这些发现与唐氏综合征和18三体综合征风险增加有关。然而,大多数有这些发现的胎儿并无染色体异常,尤其是当这些发现为孤立存在时。患者在得知这些发现时会经历相当大的焦虑,需要广泛的咨询,以便不仅将对非整倍体的焦虑,而且将对心脏和大脑结构及发育的焦虑降至最低。尽管早期研究显示与非整倍体有关联,但最近的几项研究对此关联提出了质疑。许多早期研究是在高危人群或未受益于其他筛查测试的人群中进行的。许多澳大利亚和新西兰患者在进行孕中期超声检查之前会接受旨在检测这些非整倍体的筛查测试。已经通过颈部透明带、母体血清筛查或两者的某种组合进行筛查的患者,大多数唐氏综合征和18三体综合征病例已经被检测出来,任何发现的软指标几乎肯定是假阳性。是时候重新思考这些指标的管理了。最近的证据表明,如果这些指标在其他方面为低风险的妊娠中孤立出现,那么唐氏综合征或18三体综合征的风险极小或没有增加:这些指标应被视为正常变异。文中包含了澳大利亚妇产科超声医师协会关于这些指标的共识声明。