To evaluate the value of prenatal ultrasound and magnetic resonance imaging (MRI) in the diagnosis of fetal cavum septum pellucidum (CSP) abnormalities and to analyze the pregnancy outcomes.

From January 2018 to December 2019, 34 fetuses with CSP abnormalities identified by prenatal ultrasound at the Shenzhen Maternity and Child Healthcare Hospital, the First School of Clinical Medicine, Southern Medical University were collected. Fetal MRI was performed. the newborn or fetus was examined after birth or induced labor by ultrasound and MRI. Neurodevelopment was followed by postnatal ultrasound/MRI.

Prenatal ultrasound and MRI examination results showed that in the 34 cases, there were 7 cases of holoprosencephaly (20.6%), 9 cases of small CSP (26.5%), 3 cases of absent CSP (8.8%), 7 cases of widened CSP (20.6%), 4 cases of corpus callosum dysplasia (11.8%), 1 case of abnormal echo in CSP (2.9%), 1 case of isolated septum pellucidum dysplasia (2.9%), and 2 cases of septo-optic dysplasia (5.9%). There were 24 fetuses (70.6%) who underwent fetal MRI, which revealed 11 cases of small CSP (45.8%), 5 cases of widened CSP (20.8%), 4 cases of corpus callosum dysplasia (16.7%), 2 cases of isolated septum pellucidum dysplasia (8.3%), and 2 cases of septo-optic dysplasia (8.3%). In four cases, prenatal ultrasound and prenatal MRI diagnoses were inconsistent. Fifteen cases (44.1%, 15/34) underwent induced labor (7 cases of holoprosencephaly and 8 cases of abnormal CSP with other malformations). Nineteen cases (55.9%, 19/34) were born and developed well (11 cases with small CSP, 5 cases with widened CSP, 1 case with corpus callosum dysplasia, and 2 cases with isolated septum pellucidum dysplasia and normal corpus callosum). No neurological abnormalities were observed in 19 live births between 1 month and 28 months.

Isolated small or wide CSP and isolated septum pellucidum dysplasia have good clinical prognosis during short-term follow-up.

To investigate the classification of congenital cataract, and to analyze the clinical outcome of congenital cataract.

Sonographic features and clinical outcomes of four cases of congenital cataract diagnosed by prenatal ultrasound at Shenzhen Renai Hospital between January and December 2017 were analyzed.

Prenatal ultrasound indicated that one of the four cases had dense echogenic structure, which was type 1. One case of type 2 presented hyperechogenic spot in the lens. The "double ring" sign was found in 2 cases, which was type 3. Three cases were isolated cataract, and of which maternal TORCH screens were negative. One case was associated with cerebellar hemorrhage and fetal anemia, and umbilical cord blood test of rubella virus (IgM) was positive after induced labor. Clinical outcomes: the pregnancy was terminated in 2 cases, 1 case refused follow-up, and 1 case died after birth due to intrauterine hypoxia.

Congenital cataract is an abnormal disease of lens development. Prenatal ultrasound presents dense echogenic structure, hyperechogenic spot or "double ring" sign in the lens. Combined with detailed anatomical and etiological examination, it can provide more information for prenatal consultation and early referral and intervention treatment of congenital cataract after birth.

To retrospectively analyze the pregnancy outcome and prognosis of fetal lateral ventriculomegaly, analyze the consistency of ultrasound and magnetic resonance imaging (MRI) in the diagnosis of lateral ventriculomegaly, and further explore the ultrasound cut-off value of the lateral ventricle for further clinical consultation.

A total of 100 consecutive singleton cases diagnosed by ultrasound with lateral ventriculomegaly or hydrocephalus at Shenzhen People's Hospital from January 2015 to December 2016 were selected as an observation group. According to the width of the lateral ventricle, they were divided into a mild group (＞10 to ≤12 mm, 59 cases), moderate group (＞12 to ≤15 mm, 24 cases), and severe group ＞15 mm, 17 cases). The patients were also divided into an isolated ventriculomegaly (IVM) group (51 cases) or a non-isolated ventriculomegaly (NIVM) group (49 cases) according to whether or not they had other diseases. Another 141 consecutive singletons who had a width of the lateral ventricle of ＞8 mm to ≤10 mm were selected as a control group. The clinical, laboratory, and MRI data and pregnancy outcome were recorded. The χ² test was used to analyze the difference of pregnancy outcome and prognosis among the mild group, moderate group, severe group, and control group and the difference of abnormal pregnancy outcomes between the IVM and NIVM groups. The Kappa test was used to analyze the consistency of ultrasound and MRI in the diagnosis of lateral ventriculomegaly. ROC curve was used to analyze the cut-off value of the ultrasound lateral ventricle.

The positive rates at birth in the mild group, moderate group, severe group, and control group were 6.5% (3/46) ,22.2% (2/9), 60.0% (3/5), and 5.5% (7/128), respectively, with a statistically significant difference ( χ²=22.148, P=0.001). The rate of abnormal pregnancy outcomes in the IVM and NIVM groups were 33.3% (17/51) and 63.3% (31/49), respectively, with a statistically significant difference (χ²=8.970, P=0.005). A total of 36 cases underwent prenatal and/or postnatal MRI examination. The coincidence rate of ultrasound was 77.8% (28/36), and the supplementary diagnosis rate of MRI was 19.4% (7/36). Ultrasound is generally consistent with MRI in the diagnosis of lateral ventriculomegaly (Kappa=0.543, P=0.001). The ROC curve analysis showed that the diagnostic cut-off value of the lateral ventricle suggested by ultrasound was 9.7 mm.

The more severe the lateral ventriculomegaly, the worse the prognosis of the fetus. The prognosis of NIVM is worse than that of IVM. Ultrasound is generally consistent with MRI in the diagnosis of fetal lateral ventriculomegaly, and MRI has a higher detection rate for some types of abnormalities (such as cortex, white matter, and intracranial hemorrhage). Prenatal ultrasound is an important method for the diagnosis of lateral ventriculomegaly. Further prenatal consultation should be given when the width of the lateral ventricle measured by ultrasound is greater than 9.7 mm.

To evaluate the clinical value of smart fetus (SF) technique, which includes smart fetus distinguishment and acquirement (SFDA) technique and smart fetus measurement (SFM) technique.

One thousand and five normal single fetuses between 16 and 41 weeks were selected at Affiliated Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University from August 2018 to January 2019. The standard sections, including transverse section of the thalamus (A), transverse section of the abdomen (B), and longitudinal section of the femur (C) were obtained and growth parameters, including biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL) were measured by the SF and traditional technique, separately. Sixty fetuses were selected and measured for intra- and inter-observer repeatability analyses. Wilcoxon signed rank test was used to compare the time required for section and parameter acquirement; intraclass correlation coefficients were calculated to evaluate the agreement between the two techniques, and the accuracy of SF technique for section acquisition and growth parameter measurement was evaluated.

Compared with traditiond technique, the SF had a better intra- and inter-observer agreements. The intraclass correlation coefficients of the four growth parameters were 0.998, 0.995, 0.998, and 0.998, separately. According to the expert judgement, the successful rates of sections A, B, and C acquirement by SFDA technique were 98.0%, 99.1%, and 99.6%, separately, and the accuracy for BPD, HC, AC, and FL measurement was 100%, 100%, 99.5%, and 100%, separately. The times required to obtain sections and parameters or just make the measurements by SF were both shorter than those by the traditional technique [21.26 (5.24) s vs 52.24 (14.90) s, Z=-27.366, P<0.001; 2.78 (0.66) s vs 35.70 (8.25) s, Z=-27.352, P<0.001].

SF technique is an automatic and intelligent technique for fetal standard section acquirement and growth parameter measurement, having a very high successful rate for standard sections acquirement and extremely high accuracy for fetal growth parameter measurement. Furthermore, it can greatly reduce the amount of time required for prenatal ultrasound examination, representing an efficient and reliable technique in prenatal ultrasound examination.

To assess the prenatal features of focal nodular hyperplasia and to analyze its pregnancy outcome.

The data of six cases of focal nodular hyperplasia, including prenatal ultrasonographic manifestations, laboratory examination, and pregnancy outcome, were retrospectively analyzed at the 901st Hospital of PLA, the Second Hospital of Anhui Medical University, and Affiliated Shenzhen Maternity & Child Healthcare Hospital, Southern Medical University from 2014 to 2019. The characteristics of sonograms and clinical guidelines were summarized.

In all the six cases of fetal focal nodular hyperplasia, prenatal ultrasound showed a hepatic hypoechoic mass, with a regular shape (mostly oval), clear boundary, and no obvious capsule, and Color Doppler flow imaging showed normal intrahepatic blood vessels in the mass. All six cases had full-term live births, of whom one was operated on 14 days after birth and confirmed by pathology. One case was lost to follow-up, and the remaining five cases were reexamined at the age of 0.5 and 1 years, and the lesions gradually shrank to disappear. No other abnormalities were found in the six fetuses.

Intrahepatic vascular passage is an important clue for prenatal ultrasonography in diagnosing focal nodular hyperplasia of the fetal liver.

To determine the transverse sections of corpus callosum on two-dimensional ultrasound and to establish the reference ranges for fetal corpus callosum dimensions on the transverse sections of normal foetus from 20 weeks to full term.

From June 2018 to December 2018, 10 singleton fetuses with no structural abnormalities diagnosed by prenatal ultrasound were selected as study subjects at Shenzhen Maternal and Child Health Hospital, whose parents consented to autopsy at 20-30 weeks of pregnancy due to inevitable abortion for ″cervical incompetence″ or ″unplanned birth″. A series of transverse sections obtained by three-dimensional oblique technique and frozen autopsy specimens were observed, and the characteristics of each section were summarized. The stable sections of corpus callosum on the transverse section were selected. From June 2018 to December 2018, 670 singleton pregnant women underwent routine ultrasound examination at the Ultrasound Department of our hospital. The corpus callosum diameters including the longest diameter of the corpus callosum, left to right genu diameter, anterior to posterior genu diameter, left to right splenium diameter, anterior to posterior splenium diameter, left to right body diameter, and anterior to posterior body diameter, and the angle of genu and splenium were measured at the cross-sectional plane mentioned above. Forty fetuses were randomly sampled and tested for repeatability between the two measurements. The normal reference ranges of the parameters of corpus callosum on the transverse section of the brain of each gestational week were established, and the correlation between the measured data and the scatter plot of gestational week was analyzed in parallel to establish regression equations.

Three cross sections of corpus callosum obtained by the two different methods showed the same anatomical structures. There was no significant difference in the repeatability test between two observers. The scatter plots showed that the parameters of normal fetal corpus callosum were positively correlated with gestational age (r=0.232, 0.343, 0.284, 0.182, 0.913, 0.895, 0.748, 0.787, 0.736, 0.684, and 0.734, respectively, P<0.01). The regression equations were Y=0.514X+ 52.214, Y=0.785X+ 42.897, Y=0.600X+ 47.327, Y=0.436X+ 53.056, Y=0.117X+ 0.019, Y=0.070X-0.169, Y=0.013X+ 0.054, Y=0.065X+ 0.180, Y=0.014X+ 0.064, Y=0.047X+ 0.547, and Y=0.027X-0.116, respectively.

The serial transverse sections based on 3D oblique technique and frozen autopsy specimens are relatively stable and can be used to evaluate the structure of corpus callosum. The reference charts for normal fetal corpus callosum of different gestational ages may be useful for prenatal evaluation of congenital corpus callosum anomalies.

To analyze the ultrasonographic features of conjoined twins and summarize the diagnostic skills in early pregnancy.

The ultrasonographic features, sites of union, type of fusion, related abnormalities and pregnancy outcomes were analyzed in 21 cases of conjoined twins who were checked up for early vagina bleeding during the first trimester or for 11^th-13^{th+ 6} gestational week scanning between January 2011 and December 2017 Shenzhen Maternity and Child Healthcare Hospital. The diagnostic skills of conjoined twins in early pregnancy were summarized.

Twenty-one cases of conjoined twins were diagnosed in the first trimester, whose gestational age were estimated by crown-rump length. NT measurements were obtained in 8 cases, of which 7 cases had increased nuchal translucency over 3.0 mm. The prenatal ultrasonic results of conjoined twins: there were 12 cases (12/21) of thoraco-omphalopagus, 3 cases (3/21) of cephalopagus, 3 cases (3/21) of parapagus dicephalus, 2 cases (2/21) of omphalopagus and 1 case (1/21) of ischiopagus. All cases were associated with other anomalies, including rachis deformation, single cardiac ventricle, gastroschisis, diaphragmatic hernia, omphalocele and spina bifida. Three-dimensional ultrasound imaging was helpful to confirm the types of fusion and improve facial features, which could be understood more easily. Postpartum examination showed: four cases had intrauterine fetal death, in the other 17 cases parents chose to terminate the pregnancy after ultrasound examination. All cases were confirmed to be conjoined twins by postpartum specimens.

Ultrasound examination in early pregnancy can make a clear diagnosis of the type of fusion and related abnormalities of conjoined twins, which is conducive to pregnant women for prenatal consultation.