The role of ultrasonography in recognizing the cause of fetal cerebral ventriculomegaly

Dilatation of the fetal cerebral ventricles (ventriculomegaly) is a generic sonographic sign common to several pathological entities carrying different prognoses. The main causes of fetal ventriculomegaly are aqueductal stenosis, Chiari II malformation, Dandy-Walker complex and agenesis of the corpus callosum. Ventriculomegaly is easily recognized by ultrasound by measuring the atrial width. This simple measure allows the recognition of mild forms of ventricular dilatation and is used as a screening method for ventriculomegaly. However, although the diagnosis of ventriculomegaly is easy, the prenatal identification of the cause of ventricular dilatation is a more difficult task. To this end, the evaluation of the posterior fossa in association with the visualization of the corpus callosum is a useful landmark. Research into the cause of ventriculomegaly is clinically useful, since the prognosis mainly depends on the etiology and on the presence of associated anomalies. In this article the role of prenatal sonography in recognizing the cause of ventriculomegaly and the prognostic value of the prenatal sonographic findings are discussed.     

Sonographic diagnosis of fetal cerebral ventriculomegaly: An update

Dilatation of the fetal cerebral ventricles (ventriculomegaly) is a generic sonographic sign that is common to several pathological entities carrying different prognoses. The main causes of fetal ventriculomegaly are aqueductal stenosis, Chiari II malformation, Dandy–Walker complex, and agenesis of the corpus callosum.

Ventriculomegaly is easily recognized by ultrasound by measuring the atrial width. This simple measure allows the recognition of mild forms of ventricular dilatation and is used in screening for ventriculomegaly. However, although the diagnosis of ventriculomegaly is easy, the prenatal identification of the cause of ventricular dilatation is a more difficult task. For this purpose the evaluation of the posterior fossa in association with the visualization of the corpus callosum is useful. Research into the causes of ventriculomegaly is clinically useful, since the prognosis mainly depends on the etiology and on the presence of associated abnormalities.

In this article the role of prenatal sonography in determining the cause of the ventriculomegaly is reviewed, as well as the prognostic value of the prenatal sonographic findings.     

The midsagittal view of the fetal brain: a useful landmark in recognizing the cause of fetal cerebral ventriculomegaly

AIM: To evaluate the positive predictive value of the midsagittal view of the fetal brain in recognizing the cause of ventriculomegaly diagnosed with traditional axial scan. METHODS: Fifty-eight pregnant women, referred to our Center following a generic diagnosis of ventriculomegaly have been evaluated: 38 had marked and 20 had borderline ventriculomegaly. The fetal brain was scanned by the midsagittal view using a transabdominal probe in fetuses in breech presentation or transverse lie and a transvaginal probe in fetuses in cephalic presentation. The possible cause of ventriculomegaly was postulated by combining the findings of the corpus callosum/cavum septi pellucidi complex with those of the posterior fossa. The prenatal diagnoses were compared with the anatomical specimens of aborted fetuses or with postnatal neuroimaging. RESULTS: The prenatal diagnoses were confirmed in 54/58 cases (PPV 93.1%). In the marked ventriculomegaly group, one case of partial agenesis of the corpus callosum was mistaken for a complete agenesis. In the group of borderline ventriculomegaly, two cases of partial agenesis of the corpus callosum were confused with a complete agenesis, while one case of suspected isolated ventriculomegaly was diagnosed after birth as partial agenesis of the corpus callosum. CONCLUSIONS: The sagittal scan of the fetal brain is a useful source of information and allows the contemporary view of both corpus callosum and posterior fossa, where various typical sonographic findings are present in ventriculomegaly.     

Fetal ventriculomegaly, agenesis of the corpus callosum and chromosomal translocation--case report

Real-time ultrasound was used to evaluate intracranial anatomy and ventricular size in a child with fetal ventriculomegaly. It was associated with agenesis of the corpus callosum and chromosomal translocation. Serial measurements of cerebral ventricular dilatation at various gestational age may improve perinatal management of the newborn with fetal ventricular enlargement.     

Antenatal sonographic findings of agenesis of corpus callosum

Agenesis of the corpus callosum is a central nervous system anomaly that may be associated with other intracranial abnormalities. It is easily diagnosed in the postnatal period by computed tomographic scan and ultrasound. However, its prenatal sonographic diagnosis remains a challenge. This report will evaluate three cases of fetal agenesis of the corpus callosum, review the antenatal sonographic findings and postnatal outcomes, and provide criteria for the antenatal diagnosis.     

Apert syndrome: what prenatal radiographic findings should prompt its consideration?

Apert syndrome was diagnosed in a newborn with typical facial and digital features whose only detected prenatal abnormality had been agenesis of the corpus callosum. This prompted a review of the central nervous system findings in all cases of Apert syndrome treated at the Craniofacial Center Boston Children's Hospital between 1978 and 2004. Two of 30 patients with Apert syndrome had prenatal identification of mild dilatation of the lateral cerebral ventricles and complete agenesis of the corpus callosum (ACC) documented with both ultrasound and MRI. Both had the common S252W mutation of FGFR2. Though cranial and orbital malformations typical of Apert were eventually seen in these fetuses in the third-trimester, even in retrospect, these were not detectable at mid second-trimester, ultrasound screening for congenital malformations. Hand malformations also went undetected in the second-trimester despite extensive imaging by experienced radiologists. We conclude that prenatal ultrasonographic identification of mild ventriculomegaly or ACC should stimulate a careful search for features of Apert syndrome and prompt follow-up imaging to look for bony abnormalities that have later onset. Prenatal molecular testing for Apert mutations should be considered in cases of mild ventriculomegaly and ACC.     

脑室扩张胎儿的MRI诊断及预后

目的 探讨超声发现的脑室扩张胎儿行MRI检查的临床价值,并观察脑室扩张胎儿的预后.方法 选择2006年3月至2008年7月在中国医科大学附属盛京医院行超声检查发现有胎儿脑室扩张的孕妇135例,产前检查孕周平均为32周.为进一步明确诊断行MRI检查.MRI检查发现胎儿单侧或双侧侧脑室三角区宽度为10～15 mm者诊断为轻度脑室扩张,16～20 mm者诊断为中度脑室扩张,>20 mm者诊断为重度脑室扩张.采用病例对照研究方法,对MRI诊断为单纯轻度脑室扩张胎儿和无异常胎儿,在出生后半年至1年进行丹佛智能发育筛查量表(DDST)检测,以判断单纯轻度脑室扩张胎儿在婴幼儿期的智力及生长发育状况.结果 (1)MRI诊断胎儿脑室扩张的准确率:135例超声诊断的脑室扩张胎儿中,MRI检查无明显异常56例(41.5%,56/135),单纯脑室扩张60例(60/135,44.4%),脑室扩张合并脑出血5例(3.7%,5/135),脑室扩张合并胼胝体异常12例(8.9%,12/135),脑室扩张合并小脑发育不良2例(1.5%,2/135).MRI诊断胎儿脑室扩张共79例,其中合并胼胝体异常率为15.2%(12/79).(2)MRI检查胎儿脑室扩张的分度:MRI诊断胎儿单纯脑室扩张60例,其中55例(91.7%,55/60)为轻度脑室扩张,5例为中度脑室扩张(8.3%,5/60);脑室扩张合并脑出血的5例胎儿中,1例为轻度脑室扩张、4例为中、重度脑室扩张;脑室扩张合并胼胝体异常的12例胎儿中,8例(66.7%,8/12)为中度脑室扩张,4例为重度脑室扩张(33.3%,4/12);脑室扩张合并小脑发育不良的2例胎儿均为中度脑室扩张.(3)DDST检测结果:55例单纯轻度脑室扩张胎儿中,符合随访条件的30例为病例组.无异常的56例中随访到38例,同期因其他原因行MRI检查无异常的胎儿42例,共计80例为对照组.病例组婴儿中DDST检测结果为可疑或异常4例(13.3%,4/30),正常26例(86.7%,26/30);对照组婴儿中DDST检测结果为可疑或异常10例(12.5%,10/80),正常70例(87.5%,70/80).两组分别比较,差异均无统计学意义(P>0.05).(4)MRI检查确诊的79例单纯脑窜扩张胎儿的临床结局:79例脑室扩张胎儿中,30例轻度脑室扩张胎儿及5例中度脑室扩张胎儿均妊娠至足月,出生后随访未发现婴儿异常;另有7例拒绝合作,6例孕妇坚决要求引产,失访12例.合并胼胝体发育异常的12例胎儿中,3例继续妊娠,胎儿出生后复查MRI,其诊断结果与胎儿期的MRI检查结果相同;8例孕妇坚决要求引产,失访1例.合并脑出血的5例胎儿均按孕妇意愿选择引产,尸体检查结果均证实MRI诊断正确.合并小脑发育不良的2例胎儿,1例要求继续妊娠,足月分娩,生后半年婴儿确诊为脑瘫,另有1例引产.结论 对超声发现的脑室扩张胎儿进一步行MRI检查有重要的临床验证和补充诊断价值;胎儿单纯轻度脑室扩张在出生后6～12个月期间,智力及生长发育与同龄儿无异.     

Perinatal imaging findings of inherited Sotos syndrome

OBJECTIVES: Although most cases of Sotos syndrome are sporadic, familial cases have been described. In familial cases, the most likely mode of inheritance is autosomal dominant with variable expressivity. We present the perinatal imaging findings of an inherited case. CASE: This was the second pregnancy of a 32-year-old woman with Sotos syndrome. She had given birth to her first child with macrocephaly, ventriculomegaly, macrocisterna magna and neonatal death at 28 weeks' gestation. During this pregnancy, prenatal ultrasonography at 18 weeks' gestation showed only mild dilatation of lateral ventricles. The pregnancy was uneventful until 31 weeks' gestation when fetal macrocephaly, right hydronephrosis, and polyhydramnios began to develop. At 33 weeks' gestation, dilatation of the third ventricle and fetal overgrowth were obvious. At 34 weeks' gestation, macrodolichocephaly, hypoplasia of the corpus callosum, enlargement of the lateral ventricles with prominent occipital horns, and macrocisterna magna were noted. At 36 weeks' gestation, a male baby was delivered with macrodolichocephaly, frontal bossing and a facial gestalt of Sotos syndrome. Birth weight was 3822 g, length 55 cm, and occipitofrontal head circumference 41 cm (all > 97th centile). The magnetic resonance imaging (MRI) scans demonstrated enlargement of the lateral ventricles, the trigones, and the occipital horns, hypoplasia of the corpus callosum, a persistent cavum septum pellucidum and cavum vergae, and macrocisterna magna. CONCLUSIONS: Fetuses at risk for Sotos syndrome may present abnormal sonographic findings of the brain and the skull in association with overgrowth, unilateral hydronephrosis and polyhydramnios in the third trimester. Perinatal MRI studies aid in confirmation of the diagnosis.     

Prenatal diagnosis of microdeletion 16p13.11 combination with partial monosomy of 2q37.1-qter and partial trisomy of 7p15.3-pter in a fetus with bilateral ventriculomegaly, agenesis of corpus callosum, and polydactyly

ObjectiveTo present a prenatal diagnosis of microdeletion 16p13.11 with partial monosomy of 2q37.1-qter and partial trisomy of 7p15.3-pter in a fetus with bilateral ventriculomegaly, agenesis of corpus callosum, and polydactyly.Case ReportA 41-year-old well-being Taiwanese, nulligravida woman received amniocentesis at a gestational age of 18 weeks for advanced maternal age. The fetus' karyotype showed 46,XY,der(2)t(2;7)(q36.2;p15.1). Both parents also received cytogenetic examinations and the mother's karyotype revealed 46,XX,t(2;7)(2q36.2;p15.1). High-resolution ultrasound showed the fetus had bilateral ventriculomegaly, agenesis of corpus callosum, and polydactyly of the right hand. After the termination of this pregnancy, the whole genome oligonucleotide-base array comparative genomic hybridization (CGH) by using fetal skin cells demonstrated a 8.44-Mb deletion at 2q37.1 (234602276-243041305), a 22.8-Mb duplication (65558-22869338) at 7p15.3, and an additional 1.32-Mb deletion (14968855-16292235) at 16p13.11.ConclusionArray CGH is a useful tool not only to discover the genomic imbalance at the breakpoints as well as to detect unexpectedly complex rearrangements in other chromosomes. Our case also provided evidence that genomic aberration at chromosome 16p13.11 involves in the formation of polydactyly.     

Fetal cerebral ventriculomegaly: What do we tell the prospective parents?

Fetal cerebral ventriculomegaly is a relatively common finding, observed during approximately 1% of obstetric ultrasounds. In the second and third trimester, mild (≥10 mm) and severe ventriculomegaly (≥15 mm) are defined according to the measurement of distal lateral ventricles that is included in the routine sonographic examination of central nervous system. A detailed neurosonography and anatomy ultrasound should be performed to detect other associated anomalies in the central nervous system and in other systems, respectively. Fetal MRI might be useful when neurosonography is unavailable or suboptimal. The risk of chromosomal and non-chromosomal genetic disorders associated with ventriculomegaly is high, therefore invasive genetic testing, including microarray, is recommended. Screening for prenatal infections, in particular cytomegalovirus and toxoplasmosis, should also be carried out at diagnosis. The prognosis is determined by the severity of ventriculomegaly and/or by the presence of co-existing abnormalities. Fetal ventriculoamniotic shunting in progressive isolated severe ventriculomegaly is an experimental procedure. After delivery, ventricular-peritoneal shunting or ventriculostomy are the two available options to treat hydrocephalus in specific conditions with similar long-term outcomes. A multidisciplinary fetal neurology team, including perinatologists, geneticists, pediatric neurologists, neuroradiologists and neurosurgeons, can provide parents with the most thorough prenatal counseling. This review outlines the latest evidence on diagnosis and management of pregnancies complicated by fetal cerebral ventriculomegaly.     

Mild fetal cerebral ventriculomegaly as a prenatal sonographic marker for Kartagener syndrome

Primary ciliary dyskinesia (PCD), also referred to as immotile-cilia syndrome or Kartagener syndrome, is a group of genetic disorders caused by defective cilia leading to chronic sinupulmonary infection, situs inversus and reduced fertility. Some PCD patients also have cerebral ventriculomegaly or hydrocephalus.We report here two fetuses and one newborn with mild cerebral ventriculomegaly and a suspected and/or confirmed diagnosis of PCD. These cases demonstrate that mild fetal cerebral ventriculomegaly can be a prenatal sonographic marker of PCD, certainly in fetuses with situs inversus or a history of a previous sib with PCD.     

Fetal magnetic resonance imaging (MRI) of ischemic brain injury

The aim of the present study was to demonstrate the usefulness of fetal magnetic resonance imaging (MRI) in ischemic brain injury. We report seven cases of fetal brain ischemia prenatally suspected on ultrasound (US) and confirmed by fetal MRI. Sonographic abnormalities included ventricular dilatation (n=3), microcephaly (n=1), twin pregnancy with in utero death of a twin and suspected cerebral lesion in the surviving co-twin (n=3). MRI was performed with a 1.0 T unit using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences between 28 and 35 weeks of gestation. US and MRI images were compared with pathologic findings or postnatal imaging. MRI diagnosed hydranencephaly (n=1), porencephaly (n=2), multicystic encephalomalacia (n=2), unilateral capsular ischemia (n=1), corpus callosum and cerebral atrophy (n=1). In comparison with US, visualization of fetal brain anomalies was superior with MRI. The present cases demonstrate that MRI is a valuable complementary means of investigation when a brain pathology is discovered or suspected during prenatal US.     

Prenatal diagnosis of mosaic trisomy 8 by amniocentesis in a fetus with ventriculomegaly and dysgenesis of the corpus callosum

ObjectiveWe present prenatal diagnosis of mosaic trisomy 8 by amniocentesis in a fetus with central nervous system abnormalities.Case reportA 39-year-old woman was found to have fetal bilateral ventriculomegaly and enlargement of the third ventricle on prenatal ultrasound at 32 weeks of gestation. Fetal magnetic resonance imaging examination confirmed bilateral ventriculomegaly and dysgenesis of the corpus callosum. Amniocentesis was performed subsequently. Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniotic cells revealed trisomy 8 mosaicism with a result of arr [GRCh37] (8) × 3[0.19], (X,Y) × 1. Conventional cytogenetic analysis on cultured amniocytes showed that among 108 cells in 12 colonies of three cultures, only one cell was abnormal with trisomy 8, trisomy 9 and monosomy 13, while the rest 107 cells had a normal karyotype. Repeat amniocentesis and cord blood sampling revealed a result of arr 8p23.3q24.3 (191,530–146,280,020) × 2.3 with a log₂ ratio of 0.2 compatible with 20–30% mosaicism for trisomy 8 on the uncultured amniocytes, and a result of arr 8p23.3q24.3 (191,530–146,280,020) × 2.1 with a log₂ ratio of 0.08 compatible with <10% mosaicism for trisomy 8 on the cord blood lymphocytes. Polymorphic DNA marker analysis excluded uniparental disomy 8. A malformed 2440-g dead fetus was delivered at 34 weeks of gestation with facial dysmorphism.ConclusionCytogenetic discrepancy can occur between cultured and uncultured amniocytes in mosaic trisomy 8 at amniocentesis. aCGH analysis on uncultured amniocytes is useful for confirmation of mosaic trisomy 8 at amniocentesis. Fetuses with low-level mosaicism for trisomy 8 may prenatally present ventriculomegaly and dysgenesis of the corpus callosum.     

Outcome of prenatally diagnosed agenesis of the corpus callosum

OBJECTIVE: To investigate the natural history, associated abnormalities and outcome in fetuses diagnosed prenatally with agenesis of the corpus callosum (ACC). METHODS: A retrospective study of all cases of prenatally detected ACC was performed in patients referred to two tertiary units between January 1993 and October 2003. Associated abnormalities, pregnancy outcome and infant follow-up were recorded. RESULTS: ACC was diagnosed in 117 cases. In 82 (70%) cases this was associated with other fetal structural (n = 49) or chromosomal abnormalities (n = 33). ACC was classified as an isolated prenatal finding in 35 (30%) cases. Assuming normal development in all cases lost to follow-up, significant developmental delay was present in 36% (95% CI, 15-65%) of isolated ACC. Furthermore, developmental delay was present in all cases with ventriculomegaly of at least 15 mm and in one of four cases with ventricular measurements less than 15 mm. CONCLUSIONS: The outcome of prenatally detected ACC is mainly dependent on the presence or absence of associated anomalies. The full assessment of fetal ACC mandates karyotyping, MRI and a search for more subtle ultrasound features of certain genetic syndromes. In this series, at least 36% (95% CI, 15-65%) of cases with isolated ACC exhibited significant developmental delay when assessed postnatally.     

磁共振检查在确定胎儿脑室扩张疾病诊断中的临床适应证探讨

目的 通过对产前超声筛查出的脑室扩张胎儿行磁共振检查,探讨其确定诊断的适应证和应用价值.方法 2006年3月至2007年10月在中国医科大学附属盛京医院行产前超声检查的胎儿26 072例,其中产前超声筛查出胎儿脑室扩张104例,超声筛查孕龄为22周+2～39周+5,平均32周+1.按Gaglioti标准对104例脑室扩张胎儿进行分组:脑室扩张10～12 mm组66例,13～15 mm组22例,16～20 mm组14例,21～25 mm组2例;按脑室扩张部位不同分为单侧脑室扩张组75例,双侧脑室扩张组29例.在超声筛查48 h内对各组胎儿行磁共振检查以确定中枢神经系统疾病诊断,并随访妊娠结局.结果 (1)胎儿脑室扩张的发生率为0.39%(104/26 072).(2)脑室扩张10～12 mm组确定诊断3例(5%,3/66),分别为小脑发育不良、脑血管畸形及胸腹联合畸形各1例,单纯脑室扩张63例;13～15 mm组确定诊断5例(23%,5/22),分别为胼胝体缺如、脑出血、脑出血合并脑脊膜膨出、脑脊膜膨出及颅内占位各1例,单纯脑室扩张17例;16-20 mm组确定诊断6例(43%,6/14),分别为胼胝体缺如4例、脑出血1例、胼胝体缺如合并脑室出血1例,单纯脑室扩张8例;21～25 mm组确定诊断2例(2/2),分别为胼胝体缺如1例、脑出血1例,无单纯脑室扩张.10～12 mm组确定诊断率与其他3组比较,差异有统计学意义(P＜0.01).(3)单侧脑室扩张组中确定诊断4例(5%,4/75),双侧脑室扩张组中确定诊断12例(41%,12/29),两组比较,差异有统计学意义(P＜0.01).(4)104例脑室扩张胎儿中磁共振确定中枢神经系统疾病诊断16例,诊断率为15%.16例疾病胎儿中引产15例,尸体检查结果与磁共振确定疾病诊断完全相同;1例为胼胝体缺如,脑室扩张15 mm,在观察下妊娠至足月分娩,为正常新生儿;其余88例均妊娠至足月分娩,为健康新生儿.结论 超声筛查胎儿侧脑室扩张≥16 mm或双侧脑室扩张时,建议行磁共振检查以确定胎儿中枢神经系统的疾病诊断;脑室扩张≤12 mm的单纯侧脑室扩张不必行磁共振检查,可行超声动态观察,当发现胎儿脑室扩张程度有增加趋势时再行磁共振检查以明确诊断.     

Chromosome 1p32-p31 deletion syndrome: prenatal diagnosis by array comparative genomic hybridization using uncultured amniocytes and association with NFIA haploinsufficiency, ventriculomegaly, corpus callosum hypogenesis, abnormal external genitalia, and intrauterine growth restriction

ObjectiveTo present prenatal diagnosis of chromosome 1p32-p31 deletion syndrome with NFIA haploinsufficiency, ventriculomegaly, corpus callosum hypogenesis, abnormal external genitalia, and intrauterine growth restriction and to review the literature.Materials, Methods, and ResultsA 26-year-old, primigravid woman was referred for amniocentesis at 30 weeks of gestation because of hydrocephalus and short limbs. Prenatal ultrasound showed macrocephaly, prominent forehead, ventriculomegaly, corpus callosum hypogenesis, micrognathia, and ambiguous external genitalia. Amniocentesis was performed, and array comparative genomic hybridization using uncultured amniocytes revealed a 22.2-Mb deletion of 1p32.3-p31.1 [arr cgh 1p32.3p31.1 (55,500,291 bp–77,711,982 bp)×1] encompassing the genes of NFIA, GPR177, and 89 additional genes. Cytogenetic analysis revealed a karyotype of 46,XX,del(1)(p31.1p32.3)dn. At 33 weeks of gestation, a dead fetus was delivered with a body weight of 1536 g (<5^th centile); relative macrocephaly; a broad face; prominent forehead; hypertelorism; anteverted nostrils; micrognathia; low-set ears; and abnormal female external genitalia with labial fusion, labial hypertrophy, absence of vaginal opening, and clitoral hypertrophy. Polymorphic DNA marker analysis determined a paternal origin of the deletion.ConclusionPrenatal diagnosis of ventriculomegaly with an abnormal corpus callosum should alert subtle chromosome aberrations and prompt molecular cytogenetic investigation if necessary. Fetuses with chromosome 1p32-p31 deletion syndrome and haploinsufficiency of the NFIA gene may present ventriculomegaly, corpus callosum hypogenesis, abnormal external genitalia, and intrauterine growth restriction in the third trimester.     

Antenatal diagnosis of partial agenesis of the corpus callosum: a benign cause of ventriculomegaly

Dilation of the posterior horns of the cerebral ventricles may be an early finding of fetal hydrocephalus, but it is also the hallmark of partial agenesis of the corpus callosum. Reported is the first precise prenatal diagnosis of posterior agenesis of the corpus callosum. Accurate diagnosis allows for appropriate obstetric management.     

Aneuploidy and isolated mild ventriculomegaly. Attributable risk for isolated fetal marker

BACKGROUND: Does the prenatal ascertainment of isolated mild ventriculomegaly increase the a priori risk for aneuploidy when isolated or not associated with advanced maternal age? Does isolated mild ventriculomegaly increase the risk for pediatric developmental delay? METHODS: The Wayne State University (WSU) Reproductive Genetics abnormal case data base and the Madigan Army Medical Center (MAMC) experience were reviewed to compare the rates of aneuploidy for cases with fetal ventriculomegaly. Cases were classified by maternal age and associated sonographic markers of aneuploidy. Aneuploidy rates were compared between the isolated ventriculomegaly, ventriculomegaly with advanced maternal age (AMA), and ventriculomegaly associated with multiple anomalies. Rates of aneuploidy were compared to identify association. RESULTS: A total of 118 cases with ventriculomegaly were identified for comparison. Ninety-four cases were identified in the WSU cohort; 46 demonstrated isolated ventriculomegaly alone, and aneuploidy was present in 3/25 (12%) with invasive fetal testing, 0/24 (0%) cases in the MAMC cohort demonstrated aneuploidy. Isolated mild ventriculomegaly cases at MAMC were identified for further tests. DISCUSSION: Although the two study populations vary in age and risk distributions, the attributable risk for isolated mild ventriculomegaly poses a counseling conundrum due to the neurodevelopmental implication of this minor dysmorphism more so than its association with aneuploidy.     

Sonographic findings in fetal viral infections: a systematic review

Viral infections are a major cause of fetal morbidity and mortality. Transplacental transmission of the virus, even in subclinical maternal infection, may result in a severe congenital syndrome. Prenatal detection of viral infection is based on fetal sonographic findings and polymerase chain reaction to identify the specific infectious agent. Most affected fetuses appear sonographically normal, but serial scanning may reveal evolving findings. Common sonographic abnormalities, although nonspecific, may be indicative of fetal viral infections. These include growth restriction, ascites, hydrops, ventriculomegaly, intracranial calcifications, hydrocephaly, microcephaly, cardiac anomalies, hepatosplenomegaly, echogenic bowel, placentomegaly, and abnormal amniotic fluid volume. Some of the pathognomonic sonographic findings enable diagnosis of a specific congenital syndrome (eg, ventriculomegaly and intracranial and hepatic calcifications in cytomegalovirus, eye and cardiac anomalies in congenital rubella syndrome, limb contractures and cerebral anomalies in varicella zoster virus). When abnormalities are detected on ultrasound, a thorough fetal evaluation is recommended because of multiorgan involvement. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader should be able to recall that both clinical and subclinical maternal viral infections can cross the placenta, explain that there are specific sonographic findings along with laboratory findings to detect infectious agents, and state that when sonographic abnormalities are detected fetal viral infections need to be considered.     

胎儿常见中枢神经系统异常的临床咨询

胎儿中枢神经系统（central nervous system,CNS）异常是常见的先天性出生缺陷,也是产前检查与咨询的重要内容。文章首先介绍了CNS产前超声的检查方法,包括妊娠早期筛查、中期筛查与针对性检查的切面、技术、方法与结构。并根据总体预后,将CNS异常分为致死性异常、非致死性异常、软指标或微小异常三类进行咨询,主要阐述了露脑-无脑畸形、无叶全前脑、Dandy Walker畸形、胼胝体发育不全、蛛网膜囊肿、脉络膜囊肿、侧脑室增宽等常见异常的产前诊断策略、合并相关异常、遗传评估和预后等信息。