Analysis of the results of non-invasive prenatal testing (NIPT) in 545 pregnant women in advanced maternal age.

OBJECTIVE: This research aimed to explore the value of non-invasive prenatal testing (NIPT) as a prenatal screening method for common aneuploidy in pregnant women in advanced maternal age. PATIENTS AND METHODS: A retrospective analysis was conducted on a cohort of 545 mothers with singleton pregnancy who were of advanced age and underwent NIPT testing voluntarily at the Second Affiliated Hospital of Guangxi Medical University between November 2020 and February 2023. In cases where NIPT testing suggested chromosomal abnormalities, amniocentesis was conducted, karyotype analysis or gene copy number variation (CNV) testing was performed, and the pregnancy outcome was tracked. RESULTS: Among 545 pregnant women in advanced maternal age, 11 cases had high risk of NIPT, and the detection rate was 2.02%. Among 11 pregnant women deemed to be at high risk for NIPT, 10 cases underwent amniotic fluid puncture, and one case refused amniocentesis despite a suggestive chromosomal abnormality in NIPT. The overall rate of amniocentesis was 1.83%. Among 11 pregnant women deemed to be at high risk for NIPT, the results suggested that 5 of them had trisomy 21, 1 had trisomy 18, 2 had sex chromosome abnormalities (specifically, 47, XYY), and 3 had other autosomal abnormalities. The positive predictive values of NIPT were 100.00% for the cases of trisomy 21 and trisomy 18, while the values were 0.00% for the cases of sex chromosome abnormalities and other autosomal abnormalities, respectively. After the follow-up, each of the 6 cases that were diagnosed with definite chromosomal abnormalities during prenatal screening opted to induce labor and terminate the pregnancy, including 5 cases that exhibited a high risk of trisomy 21 (47, XN,+21) and 1 case that showed a high risk of trisomy 18 (47, XN,+18). One instance of NIPT indicated a potential abnormality in the sex chromosomes, the individual declined to undergo amniocentesis. Another instance of NIPT suggested a sex chromosome abnormality, amniocentesis revealed a deletion of 0.72 Mb in the 4q22.1 region. They all had normal pregnancies and normal newborns. The remaining three cases had normal prenatal diagnoses (46, XN) and experienced normal pregnancies with healthy neonatal outcomes. CONCLUSIONS: NIPT has demonstrated its efficacy as a screening tool in the face of increasing maternal age. As a result, it can substantially decrease the requirement for invasive prenatal diagnosis. Nonetheless, there are instances of erroneous positive outcomes in NIPT testing, and therefore, interventional prenatal diagnosis remains necessary for individuals with high-risk screening outcomes to prevent false positives or unwarranted labor induction.

Pheochromocytoma in pregnancy: a case report.

BACKGROUND: Pheochromocytoma (PHEO) in pregnancy is a rare disease, and the management of this situation is not well established. The misdiagnosis of the disease often leads to adverse outcomes for both mothers and infants. CASE REPORT: Here, we describe a case of a pregnant woman at 25 weeks' gestation presenting with headache, chest tightness, and shortness of breath, which was found to have a left adrenal mass and hypertensive urgency and diagnosed pregnancy with PHEO in our hospital. The timely diagnosis and proper treatment came with an optimal maternal and fetal outcome. CONCLUSIONS: The case of pheochromocytoma in pregnancy we report demonstrated that early diagnosis and a multidisciplinary approach ensured a favorable prognosis for both maternal and fetal, and we also addressed the importance of individual basis evaluation during the whole journey.

Analysis of the anemia characteristics in early pregnancy and outcomes of pregnant women with hemoglobin H disease.

OBJECTIVE: This study aimed to analyze the anemia characteristics in early pregnancy of pregnant women with hemoglobin H (Hb H) disease and their pregnancy outcomes, and to provide reference to the pregnancy management and treatment of these women. PATIENTS AND METHODS: Twenty-eight cases of pregnant women who had been diagnosed with Hb H disease in the Second Affiliated Hospital of Guangxi Medical University from August 2018 to March 2022 were retrospectively analyzed. Moreover, 28 cases of normal pregnant women in the same period were randomly enrolled as a control group for comparison. The means and percentages of the anemia characteristics in early pregnancy and the pregnancy outcomes were calculated and the analysis of variance, Chi-square test, and Fisher's exact test were applied for comparison. RESULTS: A total of 13 cases of missing type (46.43%) and 15 cases of non-missing type (53.57%) were observed in the 28 cases of pregnant women with Hb H disease. The genotypes were as follows: 8 cases of -α3.7/--SEA (28.57%), 4 cases of -α4.2/--SEA (14.29%), 1 case of -α4.2/--THAI (3.57%), 9 cases of αCSα/--SEA (32.14%), 5 cases of αWSα/--SEA (17.86%), and 1 case of αQSα/--SEA (3.57%). Twenty-seven patients with Hb H disease (96.43%) were anemic, including 5 cases of mild anemia (17.86%), 18 cases of moderate anemia (64.28%), 4 cases of severe anemia (14.29%), and 1 case of non-anemia (3.57%). Compared with the control group, the Hb H group had significantly higher red blood cell count and significantly lower Hb, mean corpuscular volume, and mean corpuscular hemoglobin, and the differences were statistically significant (p < 0.05). The Hb H group had higher incidence rates of blood transfusion during pregnancy (BTDP), oligohydramnios fetal growth restrictions (FGR), and fetal distress than the control group. The weights of neonates were lower in the Hb H group than in the control group. Statistically significant differences were found between these two groups (p < 0.05). CONCLUSIONS: The genotype missing type of pregnant women with Hb H disease was mainly -α3.7/--SEA and the non-missing type was mainly αCSα/--SEA. Hb H disease can easily cause various degrees of anemia (mainly moderate anemia in this study). Moreover, it can increase the incidence rate of pregnancy complications such as BTDP, oligohydramnios, FGR, and fetal distress, which will reduce the weight of neonates and seriously affect maternal and infant safety. Therefore, maternal anemia and fetal growth and development should be monitored during pregnancy and delivery, and transfusion therapy should be used to improve adverse pregnancy outcomes caused by anemia when necessary.

Association of MTHFR gene C677T polymorphism with pregnancy outcome.

OBJECTIVE: The two objectives of the present study were to analyze the correlation between pregnancy outcomes and methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism, and to provide evidence for clinical improvement of adverse pregnancy outcomes. PATIENTS AND METHODS: 1,995 cases of pregnant women were selected as objects of the study, and underwent MTHFR gene C677T polymorphism detection in the Second Affiliated Hospital of Guangxi Medical University from October 2020 to September 2021, in which 919 cases whose pregnancy outcomes could be tracked. According to the result of MTHFR gene C677T polymorphism detection, 1,995 cases of pregnant women were classified into a wild-type (CC) group, heterozygous (CT) group, or homozygous (TT) group, and the distributions of MTHFR gene C677T polymorphism in pregnant women were analyzed. In addition, according to complications, 919 cases of pregnant women whose pregnancy outcomes could be tracked were divided into the normal pregnancy group (676 cases), GDM group (146 cases), HDP group (47 cases), abnormal fetus group (13 cases), and spontaneous abortion group (37 cases), and the genotype distributions of MTHFR gene C677T in each group were analyzed. Besides, according to genotype, 919 cases of pregnant women whose pregnancy outcome could be tracked were divided into CC group (515 cases), CT group (289 cases), and TT group (115 cases), and the correlation between genotype and pregnancy outcomes, such as fetal distress, postpartum hemorrhage, premature birth, and full-term delivery, was then analyzed. RESULTS: For the C677T locus of MTHFR gene in the 1,995 cases of pregnant women, there are 1,162 (58.25%) cases of CC genotype, 649 (32.53%) cases of CT genotype, 184 (9.22%) cases of TT genotype. The proportion of TT genotype in GDM, HDP, abnormal fetus, and spontaneous abortion groups were respectively 19.86% (29/148), 25.53% (12/47), 46.15% (6/13), 40.54% (15/37), which were significantly higher than that in normal pregnancy group (7.84%, 53/676), and there were statistically significant differences (p < 0.05). The full-term birth rate in TT group (75.65%, 87/115) was lower than those of CC group (91.26%, 470/515) and CT group (89.27%, 258/289), and there were statistically significant differences (p < 0.05). CONCLUSIONS: The TT type gene mutation at the C677T site ofMTHFR gene is closely related to conditions that contribute to a decrease in the number of full-term births and increase the risk of adverse pregnancy outcomes, including GDM, HDP, spontaneous abortion, and fetal abnormalities.

Analysis results of 579 cases of genomic copy number variation sequencing of pregnant women in prenatal diagnosis.

OBJECTIVE: This study explored the usefulness of genomic copy number variation sequencing (CNV-Seq) in the prenatal diagnosis of pregnant women. PATIENTS AND METHODS: Based on prenatal diagnostic indications, CNV-Seq analysis was done in the samples from the 579 pregnant women of the 7 subgroups that included advanced maternal age (group A), high risk noninvasive prenatal test (NIPT) (group B), high risk Down's (Group C), abnormal ultrasound findings (Group D), adverse pregnancy history (Group E), chromosome abnormalities in couples (Group F), and the mixed group (Group G). RESULTS: A total of 57 (9.84%) cases have abnormal CNV-Seq results. Among them, 21 cases were aneuploid chromosomal number abnormalities (3.63%, 21/579), and 36 cases were CNV abnormalities (6.22%, 36/579), including 7 cases of pathogenic copy number alteration (pCNA) (1.21%, 7/579) and 29 cases variants of uncertain significance (VUS) (5.01%, 29/579). The total detection rates of abnormal CNV-Seq in Group G and Group B were 20.27% (15/74) and 15.91% (14/88), which were significantly higher than those in other groups (p < 0.05). Among 36 cases of abnormal CNV-Seq, 7 cases were chromosome fragment deletion or duplication, which were pathogenic CNV, and some rare chromosomal diseases were detected. CONCLUSIONS: Patients with a high risk of NIPT or multiple indications of prenatal diagnosis are highly suspected of chromosomal diseases. CNV-Seq is a useful tool for detecting chromosome abnormalities for prenatal diagnosis of pregnant women more accurately and provides more comprehensive information for prenatal diagnosis to reduce birth defects.

Analysis results of 169 cases of chorionic villus samples of missed abortion using high throughput sequencing.

OBJECTIVE: This study aimed to evaluate the use of high-throughput sequencing (HTS) technology to detect chromosomes in chorionic villus samples of missed abortion embryos and investigate its utility in the genetic diagnosis of missed abortion. PATIENTS AND METHODS: HTS was used to assess chorionic villus samples obtained from 169 patients with missed abortions from August 2020 to March 2022, at the Second Affiliated Hospital of Guangxi Medical University. The test results were statistically analyzed. To investigate the impact of advanced age on the incidence of chromosomal abnormalities, the patients were divided into two groups: elderly (≥35 years) and nonelderly pregnant women (<35 years). RESULTS: (1) Among the samples of 169 patients, 100 (59.17%) cases of chromosomal abnormalities were detected. Among these 100, 90 (90%) had chromosomal numerical abnormalities and 10 (10%) had chromosomal structural abnormalities. (2) Chromosomal numerical abnormality was abnormalities mainly included aneuploidy (92.22%, 83/90), with trisomy (62.22%, 56/90) and monosomy (22.22%, 20/90) accounting for the majority. The top three numerical abnormalities included 18 cases of Turner syndrome (monosomy X; 20%, 18/90), 10 cases of trisomy 16 (11.11%, 10/90), and 10 cases of trisomy 22 (11.11%, 10/90). (3) Villous chromosomal abnormalities were found in 48 (70.59%) elderly pregnant women, and 52 (51.48%) nonelderly pregnant women, with statistically significant differences (p < 0.05). CONCLUSIONS: (1) Chromosomal abnormality is an important cause of missed abortion, it majorly includes chromosomal numerical abnormality, of which most cases are of aneuploidy. (2) Advanced age may increase the risk of embryonic chromosomal abnormalities. (3) Villus chromosome detection using HTS has a positive value and can be used for analyzing and determining the causes of missed abortion.

New iterative cone beam CT reconstruction software: parameter optimisation and convergence study.

Cone beam computed tomography (CBCT) provides a volumetric image reconstruction from tomographic projection data. Image quality is the main concern for reconstruction in comparison to conventional CT. The reconstruction algorithm used is clearly important and should be carefully designed, developed and investigated before it can be applied clinically. The Multi-Instrument Data Analysis System (MIDAS) tomography software originally designed for geophysical applications has been modified to CBCT image reconstruction. In CBCT reconstruction algorithms, iterative methods offer the potential to generate high quality images and would be an advantage especially for down-sampling projection data. In this paper, studies of the CBCT iterative algorithms implemented in MIDAS are presented. Stability, convergence rate, quality of reconstructed image and edge recovery are suggested as the main criteria for monitoring reconstructive performance. Accordingly, the selection of relaxation parameter and number of iterations are studied in detail. Results are presented, where images are reconstructed from full and down-sampled cone beam CT projection data using iterative algorithms. Various iterative algorithms have been implemented and the best selection of the iteration number and relaxation parameters are investigated for ART. Optimal parameters are chosen where the errors in projected data as well as image errors are minimal.

High-resolution three-dimensional imaging of dislocations.

Dislocations and their interactions govern the properties of many materials, ranging from work hardening in metals to device pathology in semiconductor laser diodes. However, conventional electron micrographs are simply two-dimensional projections of three-dimensional (3D) structures, and even stereo microscopy cannot reveal the true 3D complexity of defect structures. Here, we describe an electron tomographic method that yields 3D reconstructions of dislocation networks with a spatial resolution three orders of magnitude better than previous work. We illustrate the method's success with a study of dislocations in a GaN epilayer, where dislocation densities of 1010 per square centimeter are common.