Objective To explore the genetic characteristics of fetuses with congenital heart diseases(CHD)diagnosed by prenatal ultrasound.Methods Data of 613 singletons with prenatal ultrasonic diagnosed CHD were retrospectively analyzed.The cardiac structural abnormalities were classified into 8 types.Whole-exome sequencing(WES)was performed for 40 fetuses since chromosomal karyotyping analysis and/or chromosomal microarray analysis(CMA)showed benign copy number variations(CNV)or variants of uncertain significance(VUS).Results Among 613 fetuses,479 fetuses underwent both chromosomal karyotyping analysis and CMA,genomic abnormalities were detected in 60 fetuses(60/479,12.53％).Among 134 fetuses underwent only CMA,genomic abnormalities were found in 4 fetuses(4/134,2.99％).According to results of chromosomal karyotyping analysis and/or CMA,abnormalities were noticed in 40 fetuses(40/568,7.04％)among 568 fetuses with isolated CHD,while in 15 fetuses(15/45,33.33％)among 45 fetuses with non-isolated CHD,respectively.Abnormality detection rate of chromosomal karyotyping analysis and/or CMA in fetuses with complex CHD(10/41,24.39％)was higher than that in fetuses with non-complex CHD(54/572,9.44％).Among complex CHD fetuses,abnormality detection rate was the highest in fetuses with conotruncal defect(CTD)combined with malformation of venous system(4/13,30.77％),while among fetuses with non-complex CHD,situs inversus viscerum had the highest detection rate(1/4,25.00％).Among 40 fetuses chromosomal karyotyping analysis and/or CMA showed benign CNV or VUS,WES indicated pathogenic CNV/likely pathogenic CNV(P/LP)in 3 fetuses,VUS in 3 fetuses and benign CNV in 34 fetuses.Conclusion Fetuses with CHD,especially extracardiac malformations had possibilities of genomic abnormalities.Fetuses with CTD combined with malformation of venous system had higher possibilities of genomic abnormalities.Compared with CMA alone,chromosomal karyotyping analysis combined with CMA was helpful for detecting genomic abnormalities.

Objective:To develop and test the intelligent model for automatically counting the number of vertebral ossification centers below the end of conus medullaris.Methods:From January 2021 to October 2022, 3 000 ultrasound images of the sacrococcygeal spinal middle sagittal plane were retrospectively selected from Shenzhen Maternal and Child Healthcare Hospital and Zhuhai People′s Hospital. The vertebral ossification center and spinal conus medullaris were artificially fine-marked in 2, 800 images for segmentation training. Yolov8 algorithm was used to build the segmentation model for segmentation training, and the fitting and automatic counting of vertebral ossification centers were carried out by post-processing. In the other 200 planes, the counting was performed by the artificial intelligence (AI) model, attending physician (D1), and junior physician (D2), and the accuracy of their performance were evaluated by a specialist physician. The accuracy and the time spent between D1, D2, and AI were compared.Results:The accuracy of AI model segmentation fitting and counting reached 95.00% (190/200) by the specialist physician evaluation, which was almost equal to 94.50%(189/200) by D1( P=0.823) and higher than that of 88.50% by D2(177/200)( P=0.012). The counting time spent for D1, D2, and AI model were 5.00 (4.25, 6.00)s, 7.00 (7.00, 8.00)s, 0.09 (0.08, 0.10)s, respectively, showing that the time spent by AI model was significantly shorter than that of doctors(all P<0.001). Conclusions:The trained artificial intelligence model can efficiently and accurately complete the vertebral ossification center counting below the end of conus medullaris, equivalent to the level of attending physicians. This study is expected to be further applied in the screening of fetal spina bifida and improve the automation and intelligence level of prenatal ultrasound screening.

Objective:To validate the morphological changes of the parieto-occipital sulcus on the transcalvarial axial plane between 20 and 32 weeks of gestation, simplify grade for assessing fetal parieto-occipital sulcus development, and confirm its clinical feasibility.Methods:This was a cross-sectional study analysis that included 550 cases of normal singleton fetuses between 20 and 32 weeks of gestation, who underwent routine ultrasound examinations at Shenzhen Maternity and Child Healthcare Hospital from September 2019 to June 2022. The morphological changes of the bilateral parieto-occipital sulci on the transcalvarial axial plane were observed. The development of the parieto-occipital sulcus was classified into 6 grades based on the developmental features of angulation, progressive closure, and curvilinear growth: straight or shallow arcuate (Grade 0), shallow and wide V-shaped (Grade 1), deep and narrow V-shaped (Grade 2), Y-shaped (Grade 3), I-shaped (Grade 4), and curvilinear (Grade 5). The gestational age at examination and pregnancy outcomes were recorded. The distribution of gestational weeks for fetuses with different grades of parieto-occipital sulci on the left and right sides was analyzed. The symmetry between bilateral parieto-occipital sulcus gradings within individuals, as well as the inter-observer and intra-observer reliability were assessed using the Weighted Kappa coefficient. The gender differences in asymmetry of parieto-occipital sulci grades between the left and right sides was analyzed. Moreover, a model for predicting the grade of the parieto-occipital sulcus based on gestational week was established.Results:Grade for the left parieto-occipital sulcus was obtained for 549 fetuses, while grade for the right was obtained for 550 fetuses. From 20 to 32 weeks of gestation, the morphology of the fetal parieto-occipital sulcus was divided into Grade 0-5, progressing from low to high with gestational development. Grade 0 showed that the sulcus was not visible or only had a slight arcuate indentation, occurring at 20-22 weeks; Grade 1 presented as a shallow and wide "V" shape with an obtuse angle at the top, appearing from 20 to 27 weeks; Grade 2 was a deep and narrow "V" shape with an acute angle at the top, appearing from 24 to 29 weeks; Grade 3 appeared as a "Y" shape with the top part partially closed and the bottom still open, occurring between 26 to 30 weeks; Grade 4 was a fully closed "I" shape, appearing at 29-32 weeks; Grade 5 presented as a curved shape, indicating the parieto-occipital sulcus was approaching maturity, appearing from 31 to 32 weeks. There was no statistically significant difference in the distribution of gestational weeks for bilateral parieto-occipital sulcus developmental grade ( P>0.05). Bilateral parieto-occipital sulcus grade could be assessed in 549 fetuses, of which 43 cases (7.83%) exhibited grade asymmetry with a one-grade difference between sides; such asymmetry showed no significant difference between male and female genders ( P=0.647). The weighted kappa coefficient analysis results indicated a strong consistency in the development of the parieto-occipital sulci on both sides within individuals, generally demonstrating symmetrical development ( P<0.001). The intra-observer and inter-observer weighted kappa coefficients were 0.92 and 0.75, respectively, with good consistency. Conclusions:Prenatal ultrasound via the transcalvarial axial plane enables a preliminary and rapid assessment of the development of bilateral parieto-occipital sulci, facilitating early evaluation of fetal cortical maturation.

Objective:To study the stability and morphological changes of the convexity sulci in normal fetuses between 20 and 32 weeks, and to explore the simplified grade for evaluating the convexity sulci development and analyzing its clinical significance.Methods:This study was a cross-sectional analysis. A total of 551 cases of normal singleton pregnancies between 20 and 32 weeks of gestation were retrospectively collected, who underwent routine ultrasound examinations at Shenzhen Maternity and Child Healthcare Hospital from September 2019 to June 2022. The display of the far-field convexity sulci on the transcalvarial axial plane was observed as 0 for not displayed and 1 for displayed.Further, based on the morphology and number of convexity sulci, they were classified into five grades: no sulcus displayed (grade 0), one sulcus (grade 1), two sulci (grade 2), three sulci (grade 3), and four or more sulci (grade 4). The gestational age at examination and pregnancy outcomes were recorded. The distribution characteristics of gestational weeks for each grade of the convexity sulci were analyzed, and the gestational week distribution of the left and right convexity sulci was compared to analyze bilateral symmetry. The Weighted Kappa coefficient was used to analyze inter-observer and intra-observer consistency, and curve regression analysis was employed to establish a model for predicting grade based on gestational weeks.Results:Before 25 weeks of gestation, the convexity of the fetal cranial vertex was completely smooth.The central sulcus consistently appeared after 26 weeks, while the superior frontal sulcus, intraparietal sulcus, postcentral sulcus, and precentral sulcus consistently appeared between 28 and 31 weeks. Among these, the superior frontal sulcus had a lower display rate before 29 weeks. By 32 weeks, all convexity sulci of the cranial vertex should be visible. Three hundred and eleven fetuses were graded for the left, and 240 fetuses were graded for the right. The developmental grade of the convexity sulci increased from Grade 0 to Grade 4 as the gestational age progressed. Grade 0 appeared between 20-26 weeks, grade 1 between 25-28 weeks, grade 2 between 26-28 weeks, grade 3 between 27-30 weeks, and grade 4 between 27-32 weeks. The distribution of grade did not differ significantly between the left and right sides of grade 0, 1, 3 and 4 (all P>0.05), while there was a significant difference in the distribution of gestational age between the convexity sulci of grade 2 ( P<0.05). The Weighted Kappa coefficients for intra-observer and inter-observer consistency were 0.94 and 0.86, respectively, indicating strong consistency. Conclusions:The simplified grade for assessing the development of convexity sulci in normal fetuses on the transcalvarial axial plane via prenatal ultrasound can provide a preliminary evaluation of the maturation of convexity sulci in fetuses between 20 and 32 weeks of gestation.

Objective:To assess the ultrasonographic features and potential diseases of fetal abnormal sylvian fissure(SF), and to explore the value of whole-genome sequencing (WGS) in prenatal detection.Methods:A total of 28 fetuses with a sonographic diagnosis of abnormal SF in Shenzhen Maternal and Child Health Hospital Affiliated to Southern Medical University between October 2018 and October 2020 were prospectively included. The fetal brain was evaluated by neuroultrasound and intrauterine MRI in detail. Amniotic fluid/cord blood obtained by amniocentesis or tissue samples from umbilical cord after birth were collected for WGS. Pregnancy outcomes and postnatal MRI were recorded, and neurodevelopment of live-born infants was followed up for more than 24 months after delivery.Results:During the study period, 28 fetuses with abnormal SF were identified, with a gestational age of 21.3-30.0 (24.8±2.0) weeks. Abnormal SF presented in MCD ( n=15, 53.6%), chromosomal anomalies ( n=3, 10.7%) or single-gene genetic syndromes ( n=3, 10.7%) with the affected fetuses showing developmental delay, hydrocephalus or leukomalacia ( n=4, 14.2%), corpus callosal agenesis with large interhemispheric cysts ( n=1, 3.6%), benign subarachnoid space enlargement with arachnoid cysts ( n=1, 3.6%), and multiple malformations ( n=1, 3.6%). Among the 15 cases with MCD, the most common pathology was lissencephaly/pachygyria, followed by schizencephaly, severe microcephaly, hemimegalencephaly with paraventricular heterotopia, and polymicrogyria. Abnormal SF presented bilaterally in 23 fetuses and unilaterally in 5. All cases were categorized into six types depending on SF morphology in the transthalamic section: no plateau-like or a small insula, linear type, irregular corrugated SF, Z-shaped, and cyst occupying type. In addition to abnormal SF, associated anomalies or mild variations were identified in all fetuses. There were 17 cases underwent intrauterine MRI, and 13 cases underwent postnatal MRI examination.And 25 pregnancies were terminated; 3 were born alive, and 2 had typical syndromic changes with poor neurodevelopmental prognosis. A related pathogenic genetic variant was detected in 57.1% (16/28) fetus, and the incidence of single nucleotide variants(SNVs) was 42.9% (12/28), among which de novo SNVs accounted for 91.7% (11/12). Conclusions:Fetal abnormal SF could be classified based on the ultrasonographic features of transthalamic section. Fetal abnormal SF may indicate MCD, some chromosomal abnormalities or single-gene genetic syndromes that may lead to poor neurodevelopmental outcomes, and may be affected by extra-cortical factors. It is suggested to carry out targeted prenatal genetic diagnosis for fetuses with abnormal SF.

Objective:To observe the morphological changes of the sylvian fissure on the transthalamic section of fetal brain at 20-32 weeks, and grade the fetal sylvian fissure development by means of a simple scoring system and explore its clinical feasibility.Methods:From September 2018 to June 2020, 487 normal single fetuses of 20-32 weeks were examined in Shenzhen Maternal and Child Health Hospital Affiliated to Southern Medical University. The sylvian fissure maturation was analyzed on the transthalamic section of fetal brain at 20-32 weeks and was graded from 0 to 5: un-visualized (grade 0), shallow arc (grade 1), obtuse-angled platform (grade 2), right-angled platform (grade 3), acute-angled platform (grade 4), and closed operculum (grade 5). The pregnancy outcomes and gestational age were recorded.Statistical analysis was performed by SPSS 20.0 software using box plot, Mann-Whitney U test, Weighted Kappa coefficient. Results:Left sylvian fissuer grades were obtained in 280 fetuses and right sylvian fissure grades were obtained in 247 fetuses. The fetal sylvian fissure maturation at 20-32 weeks was graded from 0 to 5, which increased with advancing gestation. Grade 0 only appeared in 3 fetuses at 20 weeks, and 99.4% fetuses at 20 weeks had grade ≥1. Grade 1 appeared in 20-22 weeks, grade 2 in 20-25 weeks, grade 3 in 22-26 weeks, grade 4 in 25-32 weeks, and grade 5 in 27-32 weeks. Box-plot and Mann-Whitney U test showed that gestational week distribution of sylvian fissure at all grades was symmetric on both sides ( P>0.05). The Weighted Kappa coefficients were 0.857(95% CI=0.750-0.957) and 0.939 (95% CI=0.859-1.000), respectively, with strong consistency regarding inter- and intra-observer agreements. Conclusions:Fetal sylvian fissure maturation at 20-32 weeks can be evaluated by means of a simple scoring system with symmetrical grading of both sides.

Objective:To assess the significance of counting the number of caudal vertebral ossification centers (OCN) below fetal terminal conus medullaris in the screening for closed spina bifida and tethered cord syndrome (TCS).Methods:The OCN was counted in 961 normal fetuses(normal group) between 17 and 41 gestational weeks and in 140 fetuses with closed spina bifida or tethered cord syndrome(abnormal group) from Jan.2013 to Dec.2020 in Affiliated Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University, Women and Children′s Hospital, School of Medicine, Xiamen University and Maternity and Child Health Care of Guangxi Zhuang Autonomous Region. The OCN was counted in the dorsal mid-sagittal section of fetal caudal spine.The reliability and agreement test were evaluated by intraclass correlation coefficients in another 50 normal fetuses. The OCN was compared between two groups. ROC curve and the cut-off value were constructed and calculated.Results:In normal group, the N increased with the growing of gestational age.In the subgroup of 17-20 weeks, the OCN ranged from 5 to 7 in most fetuses. In the others subgroups, the OCN was equal to or greater than 6 in 99.9% cases and more than 6 in 97.1% cases. In abnormal group, OCN was less than 7 in 93.0% fetuses and less than 6 in 82.8% cases. There were statistical differences between the two groups except for the subgroup of 17-20 gestational weeks( P<0.05). With the cut-off value of 6.5, the specificity and sensitivity were 93.0% and 94.3% respectively for predicting the presence of closed spinal dysraphism or TCS. Conclusions:OCN is a simple way to evaluate the position of conus medullaris and to screen for the skin-covered spine dysraphism or TSC. OCN is more than 6 in most normal fetuses. Further evaluation of spine is required in fetuses with N less than or equal to 6.

Objective To evaluate the position of the fetal conus medullaris during pregnancy and its value in detecting tethered cord syndrome(TCS). Methods Nine hundred and seventy-four normal fetuses and 46 fetuses with TCS between 15 and 41 weeks gestation were involved in the study.Parameters D 1 (the distance between the end of the conus medullaris and the caudal edge of last vertebral body ossification center) and D2 (the distance from the end of the conus medullaris to the caudal skin namely the intersection point of the extending line of D1 and the skin) were measured in the caudal midsagittal plane of the spine. Sixty normal fetuses were chosed randomly for interobserver variability.Correlation analysis between these two parameters and gestational age(GA) were conducted and the normal reference value of these parameters were calculated in normal group. The ratios of growth parameters ( Biparietal diameter, Head circumference,Abdominal circumference,Femur length) to D1 and D2 were calculated separately to observe the difference of the ratios between two groups. All the parameters and ratios of normal fetuses were compared with that of TCS cases.Results There was no significant difference in D1 and D2 between two observers.A significant linear correlation between the parameters and GA was found in normal group,linear regression equations were D1=0.251 GA -2.265 cm (R2=0.926,P <0.01) and D2=0.267 GA -1.812 cm(R2=0.928,P <0.01),respectively.D1 and D2 were much lower in normal group than in abnormal group (all P <0.01). The ratios of the growth parameters to D1 and D2 were relatively stable and had statistically differences between two groups in different gestational age. Conclusions The methods that determination of D1 and D2 are simple and feasible,and could help to the prenatal diagnosis of TCS.

Objective To evaluate the development of cerebral sulci and gyrus in fetuses with conotruncal defect(CTD) at the second and third trimester by ultrasound,and to improve clinician′s understanding of the cerebral cortical development in fetuses with CTD.Methods The study was conducted at Shenzhen Maternity and Child Healthcare Hospital Affiliated to Southern Medicial University from December 2015 to January 2017,enrolled 180 women with single fetus,among whom 60 fetuses with CTD and gestational age between 20 weeks to 33+6 weeks were diagnosed by echocardiographic examination.CTD included persistent truncus arteriosous,tetralogy of fallot,transpofition of the great arteries and double outlet of right ventricle.Evaluation indexes of cerebral sulci and gyrus included depth and angle of parietooccipital sulcus,width and depth of sylvian fissure,uncovered width of insular,uncovered insular ratio,depth of calcarine sulcus,head circumference;evaluation indexes of hemodynamics included umbilical artery resistance index,umbilical artery pulsation index,middle cerebral artery resistance index,middle cerebral artery pulsation index,the cerebral-to-placental resistance ratio and the cerebroplacental pulsation ratio.Above indexes were measured for statistical analysis.Results At the whole gestational age in the study,depth of parietooccipital sulcus and width of sylvian fissure in CTD fetuses were smaller than those in the control group,uncovered insular ratio was larger than that in the normal group(P<0.05);middle cerebral artery resistance index,middle cerebral artery pulsation index and the cerebroplacental pulsation ratio in CTD fetuses were lower than those of the control group (P<0.05).Conclusions The change of hemodynamics in fetuses with CTD may be one of the reasons that fetuses with CTD have cerebral cortical hypoevolutism.

Objective To research fetal optic nerve,optic chiasma and optic tract size using high resolution prenatal ultrasound,establish a scan method and the reference range of optic nerve,optic chiasma and optic tract in normal fetus.Methods Based on the section of circulus arteriosus cerebri,the probe were rotated to get the chiasma section for measuring the diameter of bilateral optic nerve,optic tract and area of optic chiasma in 453 normal fetus respectively.Used gestation age and corresponding biological parameters as independent variables,the regression equation was established analyse the gender differences.Results 26-33 weeks was the preferable gestational age to visualize the chiasma section.It had good repeatability except chiasma area.The bilateral optic nerve and optic tract diameter,optic chiasma diameter and area had an increased along with the gestational age reposefully.There was no significant difference between the two sides of optic nerve and the gender.Conclusions Prenatal ultrasound can assess the size and shape of fetal optic nerve,optic chiasma and optic tract.The normal reference range,established by ultrasound,is helpful to diagnose the abnormality of optic chiasma.