Clinical Research Progress In Soft Markers Of Fetal Ultrasound

Mid-trimester ultrasound scan detects 2 types of sonographic markers suggestive of aneuploidy. Markers for major fetal structural abnormalities comprise the first type; the second type of markers are known as "soft markers".Soft markers are nonspecific,they are not in themselves abnormalities but are rather ultrasound findings which may indicate an increased risk of underlying abnormalities. Soft markers have been reported at mid-trimester ultrasounds since the 1980s. They were introduced after many studies demonstrated an association between these markers and Down syndrome in high-risk patients,and they may increase the risk of aneuploid. Many of these markers regress as pregnancy progresses. It confuses many clinicians during the consultation exercise, also brings a lot of pregnant women and their families, the spirit of burden.The published work surrounding the management of ventriculomegaly, choroid plexus cysts,posterior fossa fluid,echogenic intracardiac focus,echogenic bowel, bowel dilatation,shortened long bones, pyelectasis (renal pelvis dilatation) and renal cystic disease is reviewed,discussing the risk of fetal chromosomal abnormalities,clinical consultation and treatment decision-making ideas,to paly better role in ruduce the birth defects.Fetal cerebral ventriculomegaly (VM) is diagnosed when the width of one or both ventricles, measured at the level of the glomus of the choroid plexus (atrium), is >10 mm. We suggest to distinguish VM in three groups:severe (>15 mm), moderate (12.1-15mm) and mild(10-12mm).Normal neurological development in islolated VM:mild group 93%,moderate group 75%,severe group 62.5%,.When malformations are present, aneuploidies are found in 15% of severe VM. When malformations are not present, aneuploidies are found in 3%-15% of borderline VM.Choroid plexus cysts (CPC), unilateral or bilateral, are frequently detected in the second trimester. Choroid plexus cysts are sonolucent cysts within the choroids plexus of the lateral ventricle. Choroid plexus cyst is diagnosed one of the markers of chromsomal abnormalities. large of CPC may be associated with trisomy 18.Fetals with complicated choroid plexus cysts should be checked with karyotype.Most of the posterior fossa found could be diagnosed between 29～32 weeks gestation.The more fluid in the posterior fossa found, the more defected fetal or infant would be observed. In cases of more than 10 mm, especially more than 15 mm, anomales should be observed carefully.MRI can clearly demonstrate the cerebreller structure and examine the Dandy-Walker syndrome with cerebreller abnormality.Echogenic intracardiac focus(EIF) was originally described as a normal varianty and has been shown to be microcalcifications within the papillary muscle. It is a common finding in normal fetuses (3-5% of the normal population), has been shown to cause no functional heart defect and is not considered to be associated with an increased risk of structural heart abnormalities.There have been case reports that have suggested that multiple EIF or foci in the right ventricle are believed to be of greater significance.An isolated echogenic intracardiac focus in the fetal heart is not associated with increased risk for chromosome abnormalities.Fetal echogenic bowel is a second trimester'soft marker', which has been associated with an increased risk for cystic fibrosis, chromosome anomaly, intrauterine bleeding and infection, but most babies appear to be normal.It can indicate different pathological changes, this has important genetic significance,which should be much accounted of sonographers,aithough there are currently no universal standards in effect for diagnosis.Fetal bowel dilatation is closely related to intestinal malformation, it shows ult rasonographic diagnosis is the effective measures to diagnose fetal bowel dilatation. But the fetal bowel dilatation dose not means bowel deformity, so it is not the criterion of induced labor. So appropriate clinical management and instruction should be given.Shortened humerus and femur have both been associated with an increased risk of chromosomal abnormalities, especially Down syndrome. The most common definition is observed length divided by expected length, which is less than some number (usually0.90). The Expected length is usually correlated to the biparietal diameter to correct for differing gestations.To simplify matters, we use the definition suggested in a recent Canadian consensus, which considersshortened long bones to be less than the 2.5 times percentilefrom standard charts.Dilation of the fetal renal pelvis is a common finding at second-trimester ultrasound, with an incidence of 0.3% to 4.5% (average around 1%). Fetal hydronephrosis are mostly a transient or physiological, with the expansion,the incidences of ureteropelvic junction obstruction and posterior urethral valves increased. But the vesicoureteral reflux does not seem to change with the expansion of degree. Approximately 17% of fetuses with trisomy 21 will have pyelectasis,that is to say 1 in every 300 fetuses with isolated pyelectasis only actually has aneuploidy in three separate studies over a decade.Renal cystic disease is the common anomaly detected on antenatal ultrasound examination,including ARPDK, ADPDK, MCDK, solitary cyst, multiple cyst et al. Different fetal renal cystic diseases have different influences on the fetal outcome and the results of the fetal whole body on ultrasonography and the karyotype should be also considered when the fetal outcome will be evaluated.