Bromley B, Lieberman E, Laboda L, Benacerraf B R
Department of Obstetrics and Gynecology, Massachusetts General Hospital, Boston, USA.
Obstet Gynecol. 1995 Dec;86(6):998-1001. doi: 10.1016/0029-7844(95)00323-j.
To determine whether an echogenic intracardiac focus identified in the second-trimester fetus is related to an increased risk of Down syndrome.
During a 10-month period, all women with singleton gestations who underwent second-trimester genetic amniocentesis for non-imaging indications were evaluated prospectively by prenatal sonography. The presence or absence of an echogenic intracardiac focus was noted. Karyotypic information was obtained on each fetus.
Among the 1334 patients in the study group, 66 fetuses (4.9%) had an echogenic intracardiac focus. Four of 22 fetuses (18%) with trisomy 21 had an echogenic intracardiac focus, compared with 62 (4.7%) of 1312 fetuses without Down syndrome who also had an echogenic intracardiac focus (P = .004). Sonographic identification of an echogenic intracardiac focus was associated with a fourfold increased risk of Down syndrome (risk ratio 4.3, 95% confidence interval 1.5-12.3). The overall prevalence of Down syndrome in our study population was 1.6%. The sensitivity, specificity, and positive predictive value for using the presence of an echogenic intracardiac focus to identify a fetus with Down syndrome was 18.2, 95.3, and 6.1%, respectively. Extrapolating to a lower risk population, the positive predictive value of an echogenic intracardiac focus for detecting Down syndrome in patients at an age-based risk of one in 250, one in 500, and one in 1000 was calculated to be 1.53, 0.77, and 0.39% respectively.
Fetuses with an echogenic intracardiac focus have a significantly increased risk of Down syndrome. Although most fetuses with this finding are normal, patients carrying fetuses with an echogenic intracardiac focus should be counseled about the increased risk of trisomy 21.
确定孕中期胎儿心脏内强回声光斑是否与唐氏综合征风险增加相关。
在10个月期间，对所有因非影像学指征接受孕中期遗传羊膜腔穿刺术的单胎妊娠妇女进行产前超声前瞻性评估。记录有无心脏内强回声光斑。获取每个胎儿的核型信息。
研究组的1334例患者中，66例胎儿（4.9%）有心脏内强回声光斑。21 -三体综合征的22例胎儿中有4例（18%）有心脏内强回声光斑，而1312例无唐氏综合征的胎儿中有62例（4.7%）也有心脏内强回声光斑（P = 0.004）。超声检查发现心脏内强回声光斑与唐氏综合征风险增加四倍相关（风险比4.3，95%置信区间1.5 - 12.3）。我们研究人群中唐氏综合征的总体患病率为1.6%。利用心脏内强回声光斑的存在来识别唐氏综合征胎儿的敏感性、特异性和阳性预测值分别为18.2%、95.3%和6.1%。外推至低风险人群，对于基于年龄风险为1/250、1/500和1/1000的患者，心脏内强回声光斑检测唐氏综合征的阳性预测值分别计算为1.53%、0.77%和0.39%。
有心脏内强回声光斑的胎儿患唐氏综合征的风险显著增加。虽然大多数有此发现的胎儿是正常的，但对于怀有有心脏内强回声光斑胎儿的患者，应告知其21 -三体风险增加的情况。
