J. Perinat. Med. 2017; 45(6): 651–665

Review article

Lara Spalldi Barišić*, Milan Stanojević, Asim Kurjak, Selma Porović and Ghalia Gaber Diagnosis of fetal syndromes by three- and four-dimensional ultrasound: is there any improvement?

DOI 10.1515/jpm-2016-0416 onwards. It is not easy to make prenatal diagnosis of fetal Received December 19, 2016. Accepted February 15, 2017. Previously­ syndromes, so tools which help like online integrated ­published online May 11, 2017. databases are needed to increase diagnostic precision. The aim of this paper is to present the possibilities of dif- Abstract: With all of our present knowledge, high techno- ferent US techniques in the detection of some fetal syn- logy diagnostic equipment, electronic databases and dromes prenatally. other available supporting resources, detection of fetal syndromes is still a challenge for healthcare providers Keywords: Craniofacial anomalies; fetal syndromes; four- in prenatal as well as in the postnatal period. Prenatal dimensional ultrasound; high-definition live rendering; diagnosis of fetal syndromes is not straightforward, and prenatal diagnosis, three-dimensional ultrasound. it is a difficult puzzle that needs to be assembled and solved. Detection of one anomaly should always raise a suspicion of the existence of more anomalies, and can be a trigger to investigate further and raise awareness of Introduction possible syndromes. Highly specialized software systems According to the European Registry of Congenital Mal- for three- and four-dimensional ultrasound (3D/4D US) formations (EUROCAT), the prenatal detection rate for enabled detailed depiction of fetal anatomy and assess- 18 selected congenital anomalies excluding genetic condi- ment of the dynamics of fetal structural and functional tions ranges from 44.8% for clubfoot (talipes equinovarus) development in real time. With recent advances in 3D/4D to 98.4% for anencephaly and similar conditions, while all US technology, antenatal diagnosis of fetal anomalies genetic conditions have been prenatally detected in 72.8% and syndromes shifted from the 2nd to the 1st trimester of cases, with the range from 66.1% for Down syndrome of pregnancy. It is questionable what can and should be and 93.6% for Edwards syndrome (Table 1) [1]. The overall done after the prenatal diagnosis of fetal syndrome. The detection rate of all abnormalities is reported to be 34.5% 3D and 4D US techniques improved detection accuracy of in the EUROCAT [1]. fetal abnormalities and syndromes from early pregnancy Data on the prenatal detection rates of some syn- dromes are missing. A fetal syndrome should always be searched for and considered if at least two congenital mal- *Corresponding author: Lara Spalldi Barišić, MD, Director of Ian formations have been detected prenatally. Monogenetic­ Donald Inter-University School of , Croatian syndromes have a low prevalence rate, from 0.02 per Branch, Mlinovi 161A, 10 000 Zagreb, Croatia; and Specialist in 10,000 births for all types of acrocephalopolysyndactyly Obstetrics and Gynecology at Private Clinic Veritas d.o.o, Zagreb, to 0.96 per 10,000 births for DiGeorge syndrome [1]. Croatia, Tel.: +385-(98) 462 392, E-mail: [email protected] With the introduction of ultrasound (US), prenatal Milan Stanojević: Ian Donald Inter-University School of Medical Ultrasound, Zagreb, Croatia; and Department of Obstetrics and detection of congenital malformations became available. Gynecology, Medical School University of Zagreb, University Yet, there are still unsatisfactory detection rates in eve- Hospital “Sveti Duh” Zagreb, Croatia ryday clinical practice. Three-dimensional ultrasound Asim Kurjak: Ian Donald Inter-University School of Medical (3D US) has been claimed by some authors to increase Ultrasound, Zagreb, Croatia the detection rates of all malformations, while others are Selma Porović: Ian Donald Inter-University School of Medical Ultrasound, Sarajevo, Bosnia and Herzegovina skeptical about it. Knowledge on the prenatal detection Ghalia Gaber: Ian Donald Inter-University School of Medical rate of more than 6000 syndromes is still sparse and only Ultrasound, Abu Dhabi, UAE a few hundred and counting can be detected prenatally. 652 Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound

Table 1: Prenatal diagnosis of 18 selected congenital anomaly subgroups for registries with complete EUROCAT data from 2010 to 2014 [1].

Malformation Total cases Cases prenatally diagnosed (% of total cases)

Excluding genetic conditions All anomalies (excluding genetic conditions) 32,313 11,164 (34.5) Anencephalus and similar (excluding genetic conditions) 551 542 (98.4) Spina bifida (excluding genetic conditions) 699 602 (86.1) (excluding genetic conditions) 731 555 (75.9) Transposition of great vessels (excluding genetic conditions) 450 262 (58.2) Hypoplastic left heart (excluding genetic conditions) 310 263 (84.8) Cleft lip with or without palate (excluding genetic conditions) 1105 654 (59.2) (excluding genetic conditions) 387 270 (69.8) (excluding genetic conditions) 312 291 (93.3) Omphalocele (excluding genetic conditions) 293 263 (89.8) Bilateral renal agenesis including Potter syndrome (excluding genetic conditions) 141 128 (90.8) Posterior urethral valve and/or prune belly (excluding genetic conditions) 173 130 (75.1) Limb reduction defects (excluding genetic conditions) 724 367 (50.7) Clubfoot – talipes equinovarus (excluding genetic conditions) 1621 726 (44.8) Chromosomal Chromosomal 5787 4211 (72.8) Down syndrome 3405 2252 (66.1) Patau syndrome/trisomy 13 257 238 (92.6) Edwards syndrome/trisomy 18 769 720 (93.6)

Includes the following registries: Antwerp (Belgium), French West Indies (France), Isle de la Reunion (France), Saxony-Anhalt (Germany), Cork and Kerry (Ireland), SE Ireland, Emilia Romagna (Italy), Tuscany (Italy), Malta, N Netherlands (NL), S Portugal, Basque Country (Spain), Valencia Region (Spain), Vaud (Switzerland), Wales (UK), Ukraine.

However, implementing new ideas and knowledge from When to suspect a syndrome scientific research along with taking advantage of pro- gress in available diagnostic equipment make prenatal ­prenatally and how to detect it detection much more accurate and precise. With the recent dynamic and quick development of computer technology, Common terminology used to describe fetal syndromes like 3D high definition live (3D HDlive) silhouette and can sometimes be confusing. A wide variety of terms and flow US technology, there has been an enormous break- synonyms are used. Sometimes, there is a lack of good through in US equipment, with remarkable image quality. definitions of how many major and minor criteria should Thanks to highly specialized software systems, it is possi- be present to diagnose each syndrome. The difference in ble to view fetal anatomy in the smallest detail [2] and the prenatal detection rates for each region or country can be dynamics of fetal structural and functional development partly explained by differences in screening policies and in real time. Using four-dimensional (4D) technology, one follow-up practices, as well as the possible variations in can get an idea of the functionality of some organs and practitioners’ skills and available equipment [8]. systems, for example, the or the eye, introducing Clinical dysmorphology is a branch of clinical genetics new fields of fetal assessment like fetal neurology or fetal dedicated to the study of abnormal human development, sono-ophthalmology [3]. Some new functional tests have with emphasis on syndromes expressed mostly as altera- even been introduced in everyday clinical practice, like tions in body morphology [14, 15]. There are many patho- the Kurjak antenatal neurodevelopmental test (KANET), physiological mechanisms for fetal maldevelopment, to assess the function of the fetal brain [4–7], adding which can be described as malformation, deformation, some additional valuable input into the diagnosis of fetal disruption or dysplasia [16]. Malformation is commonly syndromes [8]. Many authors reported a shift of prenatal defined as a single localized poor formation of tissue initi- detection of fetal syndromes from the 2nd to the 1st trimes- ating a sequence of defects (e.g. anencephaly). The recur- ter of pregnancy [3, 8, 9–13]. rence risk for malformations generally range from 1% to The aim of this paper is to present and discuss the 5%. Deformation is a result of extrinsic mechanical forces possibilities of different US techniques to improve the on otherwise normal tissue, deforming it (e.g. abnormal detection rates of some fetal syndromes prenatally. faces, pulmonary and limb contractures that Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound 653 result from prolonged oligohydramnios or primary renal (2D) US should always be followed to avoid mistakes in agenesis in Potter syndrome with Potter facies). Disrup- prenatal assessment [8]. When evaluating structures like tion results from an extrinsic insult that destroys normal the fetal spine or the face, 3D/4D US renders much more tissue, altering the formation of affected structure (e.g. accurate images [18]. Magnetic resonance imaging (MRI) amniotic band syndrome). If the primary defect is absence has comparable image quality with US, which is the most of normal organization of cells into tissue, then we speak commonly used modality for pregnancy evaluation. US of dysplasia (e.g. achondroplasia) [8, 16]. provides cost-effective real-time imaging, offers high reso- Any of the mechanisms of fetal maldevelopment can lution and is considered safe for the mother and the result in altered morphology of fetal organs and systems, [19]. US is superior to any other imaging technology in which can result in the formation of a fetal syndrome if pregnancy because of the possibility to be used from the many organs are involved. The word syndrome originates early 1st trimester [18], with the possibility to assess fetal from ancient Greek meaning “running together” [17], rep- movements in almost real-time [18]. Undoubtedly, one of resenting a specific pattern of associated signs, symptoms, the best non-invasive diagnostic tools for the detection dysmorphic features and/or behaviors occurring together and visualization of fetal anomalies and syndromes is US, in the same individual [8, 14, 15]. particularly 3D/4D US [9]. With recent advances in 3D/4D Some fetal syndromes can be detected prenatally while technology, antenatal diagnosis of fetal anomalies and others cannot; some are expressed prenatally while others syndromes greatly shifted from the 2nd to the 1st trimester are not. In many cases definitive diagnosis can be made of pregnancy [9, 11, 18]. posnatally, many years later [8]. The differential diagnosis Goncalves et al. [20] reviewed 525 articles on 3D/4D of fetal syndromes is wide, and there are several available sonography and found that 3D US provides additional databases online that can be of assistance in the recogni- diagnostic information for the diagnosis of facial anom- tion of patterns of anomalies as a syndrome, sequence or alies, especially facial clefts, neural tube defects and association [8]. The most widely used online databases are ­skeletal malformations. Online Mendelian Inheritance in Man (OMIM), Orphanet, Merz and Welter [21] examined a large group of 3472 London Dysmorphology Database, Possumweb and the evaluated with detailed 2D and 3D US targeted Phenotip online database. For the sonographer, the most for fetal anomalies. The total number of defects was user-friendly database, especially designed to include all 1012. Comparing the 2D and 3D techniques, 3D US proved antenatal sonographic findings (instead of postnatal find- advantageous in 60.8% of the defects, which was related ings), is the Phenotip online database, while the London to the favorable demonstration of targeted areas in differ- Dysmorphology Database and Possumweb are non-free ent views (e.g. multiplanar, surface view) [21, 22]. databases, constructed to aid in differential diagnosis, with Only in the last several years have high-frequency the inclusion of postnatal findings. There is quick access to transducers and HDlive technology made major improve- the information, with the possibility to search by ultrasono- ments in the quality of US imaging. The 3D HDlive ren- graphic marker, a combination of a few markers or just by the dering method takes advantage of “shadowing effects” name of the syndrome. The triggers to investigate even more to improve the visualization of details on the image [23]. carefully for the syndrome could be known family history, Unlike conventional 3D surface rendering that uses a earlier pregnancy with malformed fetus/, history of fixed virtual light source and reflects the light off the skin consanguinity, exposure to some teratogenic drug or other surface, HDlive rendering calculates the propagation of agents, traveling to high-risk areas and possible exposure light through the skin and the tissue [23]. Shadows are to some infections (Zika virus, TORCH infections) or trauma created where light has moved through denser tissues. [8]. There is also the possibility to include parental markers The virtual light source can be changed and directed if present. Synonyms of the syndromes are included in the easily from any angle and can be manipulated to enhance search automatically, which makes it easier and faster. segmentation of tissue structures, define precise outlines and highlight important clinical details [23]. This tool is handy when observing surfaces, particularly of the facial Clinical application of 3D/4D area. Any suspected area or malformation can be investi- gated and visualized much better than with conventional ­ultrasound in the prenatal detection 2D US. By changing the angle of virtual light, one can of fetal syndromes adjust it perfectly to emphasize and get depth perception in visualizing a region of interest that may be an anomaly. An optimized and systematic approach (guidelines) to the A translucent effect is gained if the light source is placed evaluation of the fetus by conventional two-dimensional behind the object [23]. Enhanced smoothing is obtained 654 Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound by volume-speckle reduction imaging (V-SRI) on quality of the pericallosal artery (PA) (Figure 1) and the anterior multi-planar 3D/4D rendered images by applying volume cerebral artery (ACA) became much easier than before [12, (voxel) vs. traditional single slice (pixel) imaging. 32]. If there is a suspicion or clear prenatal diagnosis of HDlive rendering can be successfully applied during agenesis of CC (ACC), it is important to search for other fetal the entire pregnancy [18]. In the 1st trimester, normal and abnormalities or syndromes [trisomy 18, cerebro-costo-­ abnormal embryonal and fetal developments can be fol- mandibular syndrome, Walker-Warburg syndrome, Pai lowed and evaluated in the smallest detail. Early and mid- syndrome, Fryns syndrome and also fetal varicella zoster trimester anomaly scans can be aided with 3D/4D HDlive syndrome, fetal cytomegalovirus (CMV) syndrome and the technology in detecting fetal anomalies and syndromes, most recently recognized congenital fetal Zika virus syn- as suggested by many studies [10, 18, 24–26]. Only 2 years drome, etc.] [33]. Despite the fact that we are able to recog- ago, new applications in 3D US called HDlive silhouette nize some structural anomalies prenatally, the prediction and HDlive flow were launched. HDlive silhouette found of the exact extent of the damage and prognosis may still its clinical significance in imaging simultaneously the be a challenge [7, 32]. inner morphology through the outer surface in a transpar- ent fashion. This helps in mapping the exact location and volume of inner structures, which can be hyperechoic, Congenital heart defects such as bone, or hypoechoic, such as a cyst [12]. HDlive flow adds more spatial resolution to a conventional angio- Congenital heart defects (CHD) are the most common con- gram. With the simultaneous combination of both tech- genital anomalies occurring more frequently than chro- niques (HDlive silhouette and flow), one can visualize the mosomal malformations and spinal defects together. The exact location of vascular structures inside the organs and incidence is estimated to about 4–13 per 1000 live births, map the direction of the vascular flow (3D HDlive bidi- representing a significant cause of fetal mortality and rectional power Doppler). These two novel applications morbidity [34]. enabled the visualization of intracorporeal vascularity, Prenatal diagnosis of CHD by US is difficult, demand- premature forebrain, midbrain and hindbrain, as well as ing thorough training and expertise. The detection rate of flow in the brain vessels. CHD is variable and it ranges from 35% to 86% in most The use of a skin-like color tone in HDlive gave an even studies [34]. In the past, many attempts were made to more realistic impression of a live fetus, with impressive improve the prenatal detection rate of CHD. Four-dimen- pictorial illustration [3, 7–12, 18, 24–30]. Many of the earlier sional US (real-time 3D US) used for fetal cardiac assess- mentioned innovations in 3D/4D US applications are par- ment may improve visualization of cardiac anatomy and ticularly beneficial in the prenatal detection and visualiza- allow better evaluation of valvular function [20]. tion of anomalies of the fetal face and its discreet details. Early evaluation of the fetal heart as well as recog- The fascinating combination of science, research and new nition of several major cardiac abnormalities frequently technologies is all together implemented in a new upcom- coexisting in many fetal syndromes (Down syndrome, ing research program called “Give a face to a syndrome” [8, Edwards syndrome, DiGeorge syndrome, tarsal tunnel syn- 31]. Facial Dysmorphology Novel Analysis (FDNA®) is a new drome, etc.) can be obtained by 3D/4D US and improved technology that facilitates detection of facial dysmorphic by special applications [8, 12, 18, 26]. Two-dimensional US features and recognizable patterns of human malforma- is still the technique of choice for the prenatal diagnosis of tions (postnatal/adult life) to present comprehensive and CHD; however, the last decade has shown some promising up-to-date neurogenetic references available online [8, 31]. results due to advanced 3D/4D US technology [34], such as advanced spatio-temporal image correlation (STIC), volume contrast imaging (VCI) and Omni view. STIC is Brain anomalies a technological development of 3D/4D US developed to assist the detection of CHD. An automated device is incor- An important milestone in the prenatal recognition of porated into the ultrasound probe that has the capacity to normal brain development is the visualisation of corpus perform a slow sweep to acquire a single 3D volume [34]. callosum (CC) by improved ultrasound imaging; without Acquisition of volume data of the fetal heart and connec- this prenatal assessment was rather difficult. With 3D tions is done (the intraventricular septum, atrioventricu- surface rendering in the median plane, CC can be visual- lar valves, great vessels’ outflow tracts, and ductal ized with all its segments: genu, body and splenium. Addi- arch) by allowing multiplanar and surface reconstruction tionally, vascularization of CC with a 3D sonoangiogram of the heart anatomy [34]. The sonographer, even when Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound 655

Figure 1: 3D angiography (bidirectional power Doppler ultrasound imaging). (A) Normal fetal intracranial circulation. Notice the pericallosal vascularization. ∗PA (pericallosal artery), ∗ACA (anterior cerebral artery), ∗∗ACA branches, ∗∗SSS (superior sagittal sinus). (B–D) The circle of Willis presented in advanced STIC (spatio-temporal image correlation), 3D HD flow, Glass body rendering mode.

less experienced in fetal echocardiography, can acquire among them; CHD [conotruncal, ventricular septal defect volume data, which can be digitally stored and analyzed (VSD), tetralogy of Fallot] in more than 40% of cases, later or sent to a (fetal echocardiography) expert for facial dysmorphysm (hyperthelorism, bulbous nasal tip), further analysis. For better evaluation, the acquired data cleft palate, hypoplasia/aplasia of the thymus, malfor- can be also assessed in the cine loop feature [34], played mation of cortical brain development (poly­mycrogyria), in slow motion and stopped any time to evaluate cardiac missing , open spina bifida, polydactyly and clubfoot or vascular structures of interest. This application is also are the most common (Figure 2) [33]. All the above-men- very helpful in counselling the parents and showing them tioned malformations can be detected prenatally by US. where the problem is when CHD is found in the fetus. Beside the heart anomalies, thymic hypoplasia/aplasia is known to be a typical feature in this condition, and Chaoui et al. [35] suggested that fetal thymic US can be Detecting the syndrome from an additional parameter in the assessment of fetuses with CHD. Thymic hypoplasia/aplasia finding appears to the sonographer’s point-of-view: be sensitive (90%) in detecting fetuses with 22q11.2 dele- a difficult puzzle to solve tion. When defects are found, prenatal cytogenetic eval- uation should be offered. A ­frequently used acronym to DiGeorge syndrome is the microdeletion of chromosome remember the features of the syndrome is CATCH-22 (C: 22q11.2, the most common human syndrome. cardiac defects, A: abnormal faces, T: thymus aplasia/ This syndrome includes a wide spectrum of abnormalities hypoplasia, C: cleft palate, H: ­hypocalcemia) [36]. 656 Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound

A B

Figure 2: Similarity in visualisation prenatally and postnatally. (A) Prenatal 3D surface rendering image of clubfeet. (B) Postnatal image of clubfeet. Prenatally detected one malformatation, should be trigger to search for possible presence of other abnormalities.

While evaluating fetal faces, one must consider ethnic Syndromes featuring primarily craniofacial variations and normal differences. For example, an epi- anomalies canthal fold may be normal for people of Asiatic descent and for some non-Asian , but it can be considered Paramedian cleft lip (CL) or cleft palate (CP) or a combina- as a dysmorphic feature of syndromes such as Down syn- tion of the two (Figure 3) are the most common fetal facial drome, , , Williams anomalies and one of the most common fetal anomalies. syndrome, fetal alcohol syndrome, etc. Different shape They occur between the 8th and 9th gestational week and of the nose in different ethnic groups is another example can be unilateral or bilateral. If this is an isolated finding (Mediterranean, African, Asian, Hispanic and Cauca- (in less than 50% of cases), the defect can be surgically sian). A broad-beaked nose is a feature of Wolf-Hirschhorn repaired with a good postoperative result. Unfortunately, a syndrome (Greek warrior helmet syndrome) [33] and a majority of the fetuses with CL or CP have high incidence of short-beaked nose of some craniosynostosis-associated chromosomal abnormalities and other associated anoma- syndromes like , , lies as part of syndromes [37]. Carriers of Van der Woude Crouson syndrome, etc. [37]. A bulbous nose tip is feature (VdW) syndrome have facial clefts in 50% of cases. VdW of DiGeorge syndrome, as mentioned earlier. However, if syndrome has an autosomal dominant mode of inherit- there is a syndrome, there will be other associated anoma- ance, which accounts for approximately 2% of all cases of lies too. So even a small deviation from the normal can be CL and CP [37]. Incomplete unilateral small CL can easily a trigger and clue to look further and raise awareness of be missed by conventional 2D US, while 3D HDlive surface possible syndromes. rendering is a better method to detect it. Bilateral CL can

A B C D

Figure 3: Paramedian cleft lip (CL) or cleft palate (CP) or a combination of the two (CL/P). (A) Prenatal detection of unilateral paramedian right CL/P by 3D HDlive surface rendering in fetus with detected Edwards syndrome (trisomy 18). (B) Postnatal presentation of unilateral paramedian right CL/P. (C) Postnatal presentation of unilateral paramedian left only CL. (D) Post- natal presentation of bilateral paramedian CL/P. Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound 657

facial appearance (, midline facial cleft to a diverse extent, cebocephaly, flat nose). It is a common feature of some chromosomal syndromes such as Patau syndrome (trisomy 13) (Figure 4) and Edwards syndrome (trisomy 18). Trisomy 13 is the most common syndrome associated with alobar and facial clefts. However, up to 75% of holoprosencephaly cases have normal [37]. Mandibular anomalies (agnathia, micrognathia, ret- rognathia) have been described in various syndromes and seem to be very frequent, either isolated or coexisting as a part of the more heterogeneous syndrome. Two-dimensional US images first indicate an abnor- mal profile, while with the different 3D applications (Figure 5), it is possible to explore it in more detail and obtain the complete impression of its appearance and possible coexistence of other orofacial anomalies. Pierre-Robin sequence (PRS) is characterized by a triad of orofacial anomalies consisting of retrognathia, Figure 4: Postnatal findings of anophtalmia, median facial cleft and holoprosencephaly in a fetus with Patau syndrome (trisomy 13). glossoptosis and a posterior median soft CP. An osseous defect of the mandible is rarely found. Mandibular hypo- plasia is a primary defect that occurs early in gestation sometimes also be missed because it does not change the between the 7th and 11th week of gestation and causes the symmetry of facial appearance [13]. Bilateral complete CL tongue to be maintained high up in the oral cavity, which and CP, on the other hand, are most likely to be detected subsequently prevents fusion of the posterior soft palate because of the protrusion of the inner maxillary segment [16, 37]. Prenatal diagnosis of micrognathia in PRS by 3D under the nose, which is an obvious and unusual mass US can be unveiled in the 1st trimester of pregnancy, as when observing a profile of the face [37]. When checking reported by several authors [13, 38, 39]. Pooh and Kurjak for CP, 3D HDlive surface and maximum modes are valuable [13] pictorially presented mandibular hypoplasia and slow as well as 3D application of tomographic US imaging (TUI), jaw development in a case of PRS during pregnancy. Serial enabling to better determine the extent of the cleft [18]. 3D scans can be used to clearly reveal improvement and the Midline clefts are always severe and usually part of progress of mandibular growth over several weeks [13, 37]. some sequence such as holoprosencephaly, with gross The catch-up growth of the mandible occurs during the

Figure 5: Prenatal detection of micrognathia with low-set ears by 3D HDlive surface rendering. (A) In a fetus with detected Pierre- Robin sequence (PRS). (B) In a fetus with Meckel-Gruber syndrome (courtesy of S. Panchal). 658 Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound

Figure 6: Postpartum images of a baby with . Note: Hemifacial hypoplasia, external ear deformity, preauricular sinuses and tags. first year of life and the adjusted profile of the child can could occur in the timeline between the 4th and 8th weeks be expected between the 3rd and 6th year of life [38–40]. of gestation [44]. However, Wang et al. [45] analyzed data Isolated PRS (without any other associated malformation) from a large congenital birth defects registry in Spain occurs in about 50% of cases; however, in the other half and found a connection between diabetic mothers and of the cases, PRS is part of a malformation syndrome. The increased risk of their infants being born with OAV syn- clinical expression of the syndrome depends on the exist- drome. There has been speculation that poorly controlled ence and severity of associated anomalies [37]. The nature maternal diabetes interferes with cephalic neural crest of these anomalies is diverse – most commonly, the first cell migration, causing this syndrome [45]. The first sono- branchial arch anomalies, various chromosomal disorders graphic clue for the detection of this syndrome (also with (DiGeorge syndrome), collagenopathies or syndromes conventional 2D US imaging) can be finding asymmetry of associated with toxic agents such as alcohol (fetal alcohol the face due to hemifacial macrosomia or something small syndrome), etc. In the review of 115 cases of patient with and very typical as periauricular skin tags (Figure 7). PRS, as expected, 54% had PRS as an isolated finding. By using 3D surface rendering, more can be evaluated. The others included syndromes such as Stickler syndrome Unilateral craniofacial anomaly underdevelopment of one (18%), velocardiofacial syndrome (7%), Treacher Collins side of the body can include brain (cerebellar hemisphere syndrome (TCS) (5%), facial and hemifacial microsomia hypoplasia) [45], eye (micro/anophtalmia), low-set ears (3%) and other defined (3.5%) and undefined disorders with malformation, face (asymmetry of the soft tissue), (9%) [8, 40]. Facial dysmorphism commonly arises from (hydronephrosis), etc. With the application of 3D a combination of migration and inadequate formation of HDlive imaging technology, even small details of the face facial mesenchyme (especially when associated with dis- and other body parts can be visualized in a very realis- orders of the first and second branchial arches) [41]. tic way, which can be very helpful while counseling the Goldenhar syndrome (GS) or oculo-auriculo-vertebral parents. The combination of micrognathia with low-set (OAV) syndrome is the combination of such abnormalities ears is a common finding in many syndromes. Detection [37]. It is characterized by a wide spectrum of symptoms, of bilateral symmetric hypoplasia of the face, preauricular facial and associated features that may differ in range tags in combination with micrognathia may be part of TCS, and severity from one case to another (Figure 6). A classic Nager syndrome or Miller syndrome. TCS is a congenital feature of GS is asymmetric (mostly unilateral) hypoplasia disorder of craniofacial development caused by mutations of the face. Fetuses with GS have major anomalies, such in the TCOF1 on chromosome 5q32 [33]. TCS is repre- as unilateral mandibular hypoplasia with involvement sented by bilateral symmetrical otomandibular dysplasia of the temporomandibular joint and multiple skin tags (Figure 8). TCS is often associated with downward slant- around the ear, ear hypoplasia/aplasia and/or eye malfor- ing of the palpebral fissures. There could be associated mations (/anophthalmia) and vertebral head and neck defects, and abnormalities of the extremi- anomalies. Typically, these malformations are unilateral ties can be also found. The incidence of TCS is estimated (70%) and give an asymmetric appearance of the face. at 1:50,000 live births per year. The inheritance is autoso- Usually, the right side is more severely affected than the mal dominant with variation in expressivity. Cranioskel- left [42–44]. There have been some theories about the etal hypoplasia develops due to an insufficient number origin of this condition. Some authors hypothesized that of neural crest cells as a consequence of neuroepithelial the problem could be unilateral disruption of the blood progenitor cell [46]. The onset of defects occurs very supply (ischemia) to the 1st and 2nd brachial arches, which early in embryogenesis between the 4th and 8th weeks of Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound 659

Figure 7: Prenatal 3D surface rendering image of preauricular tag, postnatal images of external ear deformity, small ipsilateral half of the face and microphtalmia.

Edwards syndrome (trisomy 18), with a flattened occiput due to hypoplasia of the occipital brain lobes, brainstem and cerebellum, along with pointed frontal bones with hypoplasia of the frontal lobes of the brain. A lemon- shaped head can be seen with neural tube defects and as a part of some syndromes. A cloverleaf skull is present in different syndromes characterized by craniosynostosis, which can be found in Crouzon and Pfeiffer syndrome and in skeletal dysplasias such as thanatophoric dyspla- sia type II [37]. This shape of the fetal head develops due to premature closure of the coronal and lambdoid sutures, which causes bulging of temporal bones and confluence of anterior and posterior fontanelles. So, there are two bulges laterally (temporally) and an expansion superiorly (the anterior cranial fossa). Depending on the involvement of specific fetal skull sutures in premature fusion (cranio- Figure 8: 3D surface rendering image of fetus at 19 gestational weeks with Treacher-Collins syndrome and typical facial dysmor- synostosis), different shapes of the head may appear. phism: bilateral symmetrical otomandibular dysplasia with hypo- Apert syndrome is an autosomal dominant disorder plasia of soft tissues is observed in the malar bone, inferior orbital with a mutation found in the FGFR2 gene, chromosome rim and cheek (image courtesy of S. Panchal). 10q26.13 [33]. This syndrome has a few characteristic features that can be depicted while screening for abnor- malities. Three signs to remember would be strawberry gestation. Prenatal diagnosis so far has been reported shaped head, flat face and mitten-like hands [37]. Due to mostly in the 2nd trimester of pregnancy [39, 46, 47], but bicoronal craniosynostosis, there is brachycephaly and with more powerful 3D applications and HDlive techno- acrocephaly, resulting in a strawberry-shaped head. In logy, there is a possibility to shift the detection of TCS from other words, one can detect an abnormal skull with a flat the 2nd to the 1st trimester. With the combination of anoma- occiput, high forehead, midfacial hypoplasia (flat face), lies, suspicion of a syndrome is very essential for inform- hypertelorism of the eyes and eyelid edema by a combi- ing the geneticists who can order the gene sequencing nation of conventional 2D imaging with 3D maximum added to the usual amniocentesis (AC) panel to confirm mode (for bony structures), conventional 3D surface and the diagnosis, which otherwise would be missed [47]. 3D HDlive surface imaging. Mild ventriculomegaly can be There have been some animal studies featuring chemical detected by the 3D inversion mode and the newest appli- and genetic inhibition of the p53 protein in the attempt to cation of HDlive silhouette imaging. ACC can be an accom- prevent TCS, but so far, no effective method of prevention panying finding best detected with 3D surface rendering in humans exists [47]. in the median plane with additional 3D sonoangiogram The shape of the skull might sometimes be informa- visualization (3D HDlive bidirectional power Doppler) tive, for example, a strawberry-shaped head seen in of the absent pericallosal artery. Very specific for fetuses 660 Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound with the Apert syndrome is defect on the extremities, are limb defects (constriction rings, amputation of the called “mitten-like hands/feet”: syndactyly (soft tissue limb or digits, etc.) and anterior abdominal wall defects and osseous) of the 2nd, 3rd and 4th finger in combination (gastroschisis, omphalocele) (Figure 10) [16, 37]. Other with a broad . Pooh and Kurjak [13] published a skull abnormalities detected by US are microcephaly and case of a prenatally detected fetus with Apert syndrome . Microcephaly indicates a group of disor- by using 3D sonography. Correlation was made between ders characterized by a small head and typically asso- prenatal 3D US images of anomalies and identical post- ciated with abnormal neurological findings and mental natal appearance [13, 18]. Three-dimensional US images disabilities [37]. Microcephaly usually also implies micro- can be used to present the parents with the extent of encephaly because the head size is commonly determined the abnormalities of the face, skull and extremities [48]. by the brain size. Fetuses with prenatally suspected Parents should be counseled about prognosis, possibility microcephaly have head circumference (HC) >3 standard of different degrees of intellectual impairment and risk deviations (SDs) below the mean for gestational age [50]. of recurrence. When resulting from a de novo mutation, Different associated US features depend greatly on the recurrence risk is improbable, but if one of the parents is a etiologic factor causing microcephaly. The exact etiology carrier, the recurrence risk is 50%. There may be an asso- of most microcephaly cases is still unknown. However, it ciation between advanced paternal age and higher risk of is linked to numerous syndromes associated with chro- occurrence of Apert syndrome as a single-gene disorder mosomal abnormalities like Cornelia de Lange syndrome, [49]. To confirm the diagnosis prenatally, the option of AC DiGeorge syndrome, ­Wolf-Hirshhorn syndrome, cri-du- should be offered to the parents. chat syndrome, trisomy 13 and 9, etc., exposure to some Frontal bossing may be a typical finding in achondro- toxic agents (alcohol, drugs, chlomiphene, methotrexate, plasia (autosomal dominant condition with rhizomelic phenylalanine), maternal under-nutrition and certain limb shortening) (Figure 9) and Russell-Silver syndrome maternal infections during pregnancy, such as rubella, (, asymmetric intrauterine growth restriction toxoplasmosis, varicella and cytomegalovirus (CMV). of the skeleton with normal size of the head). Asymmetry There are reports of a new causation between maternal of the fetal skull can also be found in the fetus with amni- infection and Zika virus during pregnancy and adverse otic band syndrome (sequence). Due to rupture in the pregnancy outcomes such as microcephaly, other brain amnion, which initiates the process very early in the 1st and eye defects and pregnancy loss [51]. Zika congenital trimester of pregnancy, the amniotic band causes a wide syndrome is generally characterized by cerebral variety and severity of destructive fetal malformations, that may interfere in formation and neuronal migration depending on fetal parts that come in contact and get during early cerebral embryogenesis [52]. Other features trapped in it. When affecting the skull, asymmetric anen- of this syndrome are the following: severe microcephaly, cephaly, encephalocele, facial clefting and micrognathia lissencephaly, cataract of the eye, microophtalmia, club- can be detected. Other abnormalities that are also found foot, contractures and arthrogryposis [51–53]. Viruses

Figure 9: 3D surface rendering. (A) 3D skeleton. (B) 3D HDlive surface rendering. (C) 3D HDlive surface rendering of the same fetus at 34 gestational weeks with suspected achondroplasia. Notice typical facial features such as frontal bossing and depressed nasal bridge. Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound 661

A B C D

E F G H

Figure 10: Prenatal detection of omphalocele at 13+3 gestational weeks. Different ultrasound modes and rendering applications are used to visualize the omphalocele. (A) Conventional 2D mode. (B–D and E–G) 3D HDlive surface rendering with different angle of illumination. (H) Postnatal presentation of the baby born at 40 gestational weeks, realistic and same appearance of omphalocele in the prenatal compared to the postnatal period. such as CMV or Zika have been shown to invade the brain In addition, infection may cause scars and calcifications cells, particularly neural progenitors, infect and destroy in the brain tissue. Abnormalities such as periventricular the primary stem cells (the radial glial cells) of the brain; and intraparenchymal calcifications, ventriculomegaly therefore, there is a lack of future daughter neurons secondary to cerebral atrophy, and [54–56]. The severity of the condition may depend on the cortical abnormalities are seen and detected much earlier timing of infection during pregnancy. Microcephaly is than microcephaly itself. Besides the standard US screen- mostly the result of decreased size of the cerebral cortex. ing, fetal neurosonography as well as KANET should be

Figure 11: Prenatally detected congenital anomalies of the urinary tract. (A) Unilateral hydronephrosis in fetus at 26 gestational weeks, 3D rendering. (B) Conventional 2D image in fetus at 25 gestational weeks and obstructed urethra with distention of the bladder and hydronephrosis. (C) Conventional 2D image of fetus with massive distention of the bladder in Prune-Belly syndrome at 14 gestational weeks. 662 Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound

Figure 12: Facial appearance of fetus with Meckel-Gruber syndrome. (A) 2D conventional image of fetal profile (notice the flat face). (B–E) 3D surface rendering of fetal profile.

Figure 13: Multicystic dysplastic kidney (MCDK) found in fetus at 26 gestational weeks. (A, B) Conventional 2D images (courtesy RM. Nieto). (C, D) 3D HDlive silhouette images, volume extraction (courtesy RK. Pooh). performed and repeated in the follow-up period until the first few days of life due to the delivery. The infection should be confirmed by the and renal failure. Detection of occipital encephalocele real-time reverse transcription polymerase chain reac- in the 1st trimester is easier due to a better overview and tion (rRT-PCR) [53]. The most recent follow-up studies normal collection of amniotic fluid. Later in pregnancy, from Brazil have shown that even though some babies are there is progressive oligohydramnios and encephalocele born with a normal head size, postnatal development of microcephaly can still occur as well as significant neuro- logical sequelae also leading to arthrogryposis, a condi- tion resulting in deformities of joints [52]. In the prenatal assessment of pregnancies at risk, evaluation with 4D US and KANET could be included. Prenatal results can be compared with postnatal results of neonatal neuro- logical evaluation in the follow-up period during the first 2–3 years of life [6–8]. During a routine anomaly scan, abnormalities of fetal kidneys can be detected. A wide variety of structural and functional abnormalities can be seen (Figure 11). Dysplastic kidneys with multiple cysts [multcystic dys- plastic kidneys (MCDK)] that fluctuate in size can be found in some very severe syndromes. As MCDK are dys- functional, it could be a lethal condition called Meckel- Gruber syndrome (Figure 12) with autosomal recessive inheritance [57], if found bilaterally. Three pathogno- Figure 14: 3D HDlive surface rendering of normal appearance of monic anomalies can be found: occipital encephalocele, fetal face at 28 gestational weeks. MCDK (Figure 13) and polydactyly. Neonates die within KANET assessment by 4D. Notice the open eye. Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound 663 may be missed. Special attention should be paid to eval- approved by the authors’ institutional review board or uate both fetal kidneys because normal sonographic equivalent committee. finding of kidneys rules out the lethal Meckel-Gruber syndrome. References

Conclusion [1] EUROCAT. Prenatal screening & diagnosis. Prenatal detection (pd) rates. Available at: http://www.eurocatnetwork.eu/pre- As soon as it becomes achievable to detect congenital natalscreeninganddiagnosis/prenatal%20detection(pd)rates. (Accessed on October 11, 2016). anomalies by prenatal US, there lie questions of what can [2] Kurjak A, Pooh RK, Merce LT, Carrera JM, Salihagic-Kadic A, and should be done. Many ethical issues arise as well. Andonotopo W. Structural and functional early human develop- Modern medicine faces some problems when having the ment assessed by three-dimensional and four-dimensional possibility to extend the life of the sickest babies with sonography. Fertil Steril. 2005;84:1285–99. potentially lethal congenital syndromes. The possibil- [3] Pooh RK. A New Field of “Fetal Sono-ophthalmology” by 3D HDlive Silhouette and Flow. Donald School J Ultrasound Obstet ity to do so does not always justify the opportunity [8]. Gynecol. 2015;9:221–2. ­Generally, the idea is to find the balance between the [4] Kurjak A, Miskovic B, Stanojevic M, Amiel-Tison C, Ahmed B, benefits and limitations of US imaging. At the same time, Azumendi G, et al. New scoring system for fetal neurobehavior one should be able to optimize the recommendations with assessed by three- and four-dimensional sonography. J Perinat the expectations of the parents of a severely damaged Med. 2008;36:73–81. baby. Given the complexity of the prenatal diagnosis of [5] Kurjak A, Abo-Yaqoub S, Stanojevic M, Yigiter AB, Vasilj O, Lebit D, et al. The potential of 4D sonography in the assessment of syndromes, everything involved around it is so complex. fetal neurobehavior-multicentric study in high-risk pregnan- That includes the postnatal confirmation of the diagnosis, cies. J Perinat Med. 2010;38:77–82. determination of the prognosis aiming to help the parents [6] Stanojevic M, Antsaklis P, Kadic AS, Predojevic M, Vladareanu to deal with the sick baby and to indicate the necessity R, Vladareanu S, et al. Is kurjak antenatal neurodevelopmental of complex, lifelong and costly multidisciplinary care of test ready for routine clinical application? Bucharest consen- affected babies. sus statement. Donald School J Ultrasound Obstet Gynecol. 2015;9:260–5. Taken together, the previously described 3D/4D US [7] Kurjak A, Barišić LS, Stanojević M, Kadić AS, Porović S. Are we techniques (Figure 14) promise to advance clinicians’ ready to investigate cognitive function of fetal brain? The role accuracy in detecting fetal abnormalities and syndromes of advanced four-dimensional sonography. Donald School J as early as possible. So far, there have been many advan- Ultrasound Obstet Gynecol. 2016;10:116–24. tages of the prenatal detection of fetal syndromes, but [8] Barišić LS, Kurjak A, Pooh RK, Delić T, Stanojević M, Porović S. Antenatal detection of fetal syndromes by ultrasound: from a there is also a lot of room for improvement. As the new single piece to a complete puzzle. Donald School J Ultrasound 3D/4D US technology becomes more available to general Obstet Gynecol. 2016;10:63–77. use in everyday practice, one should be well informed and [9] Pooh RK, Kurjak A. Novel application of three-dimensional keep up with emerging new diagnostic possibilities, so HDlive imaging in prenatal diagnosis from the first trimester. J that the number of detected affected fetuses will probably Perinat Med. 2015;43:147–58. improve over time. Helping tools such as available online [10] Bonilla-Musoles F, Raga F, Castillo JC, Bonilla F Jr, Climent MT, Caballero O. High definition real-time ultrasound (HDlive) of databases integrate all necessary information for better embryonic and fetal malformations before week 16. Donald diagnostic precision. However, human involvement, School J Ultrasound Obstet Gynecol. 2013;7:1–8. knowledge and rational thinking are still irreplaceable in [11] Pooh RK, Kurjak A. 3D/4D sonography moved prenatal making the right diagnosis of fetal syndromes. ­diagnosis of fetal anomalies from the second to the first trimester of pregnancy. J Matern Fetal Neonatal Med. 2012;25:433–55. Author’s Statement [12] Pooh RK. Novel application of hdlive Silhouette and hdlive Conflict of interest: Authors state no conflict of interest. flow: clinical significance of the “see-through fashion” in pre- Material and Methods: Informed consent: Informed natal diagnosis. Donald School J Ultrasound Obstet Gynecol. consent has been obtained from all individuals included 2016;10:90–8. in this study. [13] Pooh RK, Kurjak A. Three-dimensional ultrasound in detection of fetal anomalies. Donald School J Ultrasound Obstet Gynecol. Ethical approval: The research related to human subject 2016;10:214–34. use has complied with all the relevant national regula- [14] Lyons KJ, Crandall MJ, del Campo M. Smith’s recognizable tions, and institutional policies, and is in accordance patterns of human malformation, 7th ed. Philadelphia, PA: with the tenets of the Helsinki Declaration, and has been Elsevier Saunders; 2013. 664 Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound

[15] Lanna M, Rustico MA, Pintucci A, Spaccini L, Lalatta F, ­Nicolini U. [36] Wilson DI, Burn J, Scambler P, Goodship J. DiGeorge syndrome: Three-dimensional ultrasound and genetic syndromes. Donald part of CATCH 22. J Med Genet. 1993;30:852–6. School J Ultrasound Obstet Gynecol. 2007;1:54–9. [37] Benacerraf BR. Ultrasound of fetal syndromes. 2nd ed. London: [16] Jones KL. Smith’s recognizable patterns of human malforma- Churchill Livingstone; 2008. tion. 5th ed. Philadelphia, PA: Elsevier Saunders; 1997. [38] Teoh M, Meagher S. First-trimester diagnosis of micrognathia [17] Dorland’s Illustrated Medical Dictionary online. Elsevier. as a presentation of Pierre Robin syndrome. UltrasoundObstet ­Available at: www.dorlands.com/wsearch.jsp. Gynecol. 2003;21:616–8. [18] Pooh RK, Kurjak A. Donald school atlas of advanced ultrasound [39] Tsai MY, Lan KC, Ou CY, Chen JH, Chang SY, Hsu TY. Assessment in obstetrics and gynecology. 1st ed. New Delhi: Jaypee Broth- of the facial features and chin development of fetuses with use ers Medical Publishers (P) Ltd; 2015. of serial three-dimensional sonography and the mandibular [19] Reddy UM, Filly RA, Copel JA. Prenatal imaging: ultrasonog- size monogram in a Chinese population. Am J Obstet Gynecol. raphy and magnetic resonance imaging. Obstet Gynecol. 2004;190:541–6. 2008;112:145–57. [40] Evans AK, Rahbar R, Rogers GF, Mulliken JB, Volk MS. Robin- [20] Gonçalves LF, Lee W, Espinoza J, Romero R. Three- and sequence: a retrospective review of 115 patients. Int J Pediatr 4-dimensional ultrasound in obstetric practice: does it help? J Otorhinolaryngol. 2006;70:973–80. Ultrasound Med. 2005;24:1599–624. [41] Johnson JM, Moonis G, Green GE, Carmody R, Burbank HN. [21] Merz E, Welter C. Two-dimensional and three-dimensional Syndromes of the first and second branchial arches, part 2: ultrasound in the evaluation of normal and abnormal fetal syndromes. Am J Neuroradiol. 2011;32:230–7. anatomy in the second and third trimesters in a level III center. [42] Castori M, Brancati F, Rinaldi R, Adami L, Mingarelli R, Gramma- Ultraschall Med. 2005;26:9–16. tico P, et al. Antenatal presentation of the oculo-auriculo-verte- [22] Merz E, Abramowicz JS. Three-dimensional/four-dimensional bral spectrum (OAVS). Am J Med Genet A. 2006;140:1573–79. ultrasound in prenatal diagnosis: is it time for routine use? Clin [43] Miller TD, Metry D. Multiple accessory tragi as a clue to the Obstet Gynecol. 2012;55:336–51. diagnosis of the oculo-auriculo-vertebral (Goldenhar) syn- [23] Benoit B, Levaillant JM. Voluson GE healthcare technology. drome. J Am Acad Dermatol. 2004;50(2 Suppl):S11–13. Available at: www.volusonclub.net. Accessed: 10 Dec 2016. [44] Martinelli P, Maurotti GM, Agangi A, Mazzarelli LL, Bifulco [24] Kagan KO, Pintoffl K, Hoopmann M. First-trimester ultrasound G, Paladini D. Prenatal diagnosis of hemifacial microsomia images using HDlive. Ultrasound Obstet Gynecol. 2011;38:607. and ipsilateral cerebellar hypoplasia in a fetus with ocu- [25] Hata T. HDlive rendering image at 6 weeks of gestation. J Med loauriculovertebral spectrum. Ultrasound Obstet Gynecol. Ultrason. 2013;40:495–6. 2004;24:199–201. [26] Hata T, Mashima M, Ito M, Uketa E, Mori N, Ishimura M. [45] Wang R, Martinez-Frias ML, Graham JM Jr. Infants of diabetic Three-dimensional HDlive rendering images of the fetal heart. mothers are at increased risk for the oculo-auriculo-vertebral Ultrasound Med Biol. 2013;39:1513–7. sequence: a case-based and case-control approach. J Pediatr. [27] Hanaoka U, Tanaka H, Koyano K, Uematsu R, Kanenishi K, Hata 2002;141:611–7. T. HDlive imaging of the face of fetuses with autosomal triso- [46] Paul A, Trainor PA, Dixon J, Dixon MJ. Treacher Collins syn- mies. J Med Ultrasonics. 2014;41:339–42. drome: etiology, pathogenesis and prevention. Eur J Human [28] Hata T, Hanaoka U, Mashima M. HDlive rendering image of Genetics. 2009;17:275–83. cyclopia and a proboscis in a fetus with normal chromosomes [47] Jones NC, Lynn ML, Gaudenz K, Sakai D, Aoto K, Rey JP, et al. at 32 weeks of gestation. J Med Ultrason. 2014;41:109–10. Prevention of the neurocristopathy Treacher Collins syndrome [29] Tonni G, Castigliano AP, Grisolia G, Lithuania M, Meagher S, through inhibition of p53 function. Nat Med. 2008;14:125–33. Da Silva Costa F, et al. HDlive in early gestation. J Turk Ger [48] David AL, Turnbull C, Scott R, Freeman J, Bilardo CM, van Maarle Gynecol Assoc. 2016;17:110–9. M, et al. Diagnosis of Apert syndrome in the second-trimester [30] Pooh RK. Recent advances in 3D ultrasound, silhouette ultra- using 2D and 3D ultrasound. Prenat Diagn. 2007;27:629–32. sound, and sonoangiogram in fetal neurology. Donald School J [49] Toriello HV, Meck JM. Statement on guidance for genetic Ultrasound Obstet Gynecol. 2016;10:193–200. ­counseling in advanced paternal age. Genet Med. [31] Basel-Vanagaite L, Wolf L, Orin M, Larizza L, Gervasini C, Krantz 2008;10:457–60. ID, et al. Recognition of the Cornelia de Lange syndrome phe- [50] Chervenak FA, Rosenberg J, Brightman RC, Chitkara U, Jeanty P. notype with facial dysmorphology novel analysis. Clin Genet. A prospective study of the accuracy of ultrasound in predicting 2016;89:557–63. fetal microcephaly. Obstet Gynecol. 1987;69:908–1043. [32] Merz E, Pashaj S. What is known about corpus callosum [51] De Araújo TV, Rodrigues LC, de Alencar Ximenes RA, de Barros prenatally? Donald School J Ultrasound Obstet Gynecol. Miranda- Filho D, Montarroyos UR, de Melo AP, et al. Associa- 2016;10:163–9. tion between Zika virus infection and microcephaly in Brazil, [33] The Phenotip Team. Phenotip tutorial. Available at: http://pheno- January to May, 2016: preliminary report of a case-control tip.com/possible-syndromes/. (Accessed on September 21, 2016). study. Lancet Infect Dis. 2016;12:1356–63. [34] Ahmed BI. The new 3D/4D based spatio-temporal imaging cor- [52] van der Linden V, Pessoa A, Dobyns W, Barkovich AJ, van der relation (STIC) in fetal echocardiography: a promising tool for Linden HJ, Rolim Filho EL, et al. Description of 13 infants born the future. J Matern Fetal Neonatal Med. 2014;27:1163–8. during October 2015–January 2016 with congenital zika virus [35] Chaoui R, Kalache D, Heling KS, Tennstedt C, Bommer CC, infection without microcephaly at birth, Brazil. MMWR Morb Korner H. Absent or hypoplastic thymus on ultrasound: a Mortal Wkly Rep. 2016;65;1343–8. marker for deletion 22q11.2 in fetal cardiac defect. Ultrasound [53] Melo AS de O, Aguiar RS, Amorim MMR, Tanuri A, Melo FO, Obstet Gynecol. 2002;20:546–52. Ribeiro ST, et al. Congenital Zika Virus Infection. JAMA Neurol. Barišić et al., Diagnosis of fetal syndromes by 3D/4D ultrasound 665

Published online October 3, 2016. Corrected on October 24, [56] Society for Maternal-Fetal Medicine (SMFM) Publications 2016. ­Committee. SMFM Statement. Ultrasound screening for fetal [54] Nowakowski TJ, Pollen AA, Di Lullo E, Sandoval-Espinosa C, microcephaly following zika virus exposure. Am J Obstet Bershteyn M, Kriegstein AR. Expression analysis highlights AXL Gynecol. 2016;214:B2–B4. as a candidate zika virus entry receptor in neural stem cells. [57] Barišić I, Odak LJ, Loane M, Garne E, Wellesley D, Cell Stem Cell. 2016;18:591–6. Calzolari E, et al. Prevalence, prenatal diagnosis and [55] Li C, Xu D, Ye Q, Hong S, Jiang Y, Liu X, et al. Zika virus disrupts clinical features of oculo-auriculo-vertebral spectrum: neural progenitor development and leads to microcephaly in a registry-based study in Europe. Eur J Human Genetics. mice. Cell Stem Cell. 2016;19:120–6. 2014;22:1026–33.