Thalassemia screening by third-generation sequencing: Pilot study in a Thai population.

Background: Conventional thalassemia screening takes a stepwise approach and has limitations in comprehensively identifying all spectrums of mutations. This study aimed to investigate the performance of third-generation sequencing (TGS) compared to conventional molecular testing. Methods: TGS was applied to validate all known variants detected by conventional testing and to detect missing variants in undiagnosed cases. The study was conducted at Maharaj Nakorn Chiang Mai Hospital between December 2021 and April 2022. Results: In total, 19 cases were included in this study, among which 52.6% (10/19) had known thalassemia variants, while 47.7% (9/19) cases were undiagnosed by conventional methods. All 16 variants previously detected were validated by TGS, and TGS additionally detected 43.8% (7/16) thalassemia variants for 36.8% (7/19) cases. Conclusion: TGS could provide additional genetic diagnoses compared with conventional methods. Further cost-effectiveness studies with a larger sample size are needed to explore the role of TGS in clinical practices.

Large unruptured tubal pregnancy mimicking abdominal pregnancy.

Ectopic pregnancy accounts for 1-2% of all pregnancies. Ultrasound is the primary diagnostic tool to locate pregnancy outside the uterus and identify complications such as haemoperitoneum. In inconclusive cases, MRI is an adjunctive imaging modality offering more precise tissue differentiation and helpful to location identification. Presented is an unusual case of tubal pregnancy. The patient in her 30s, who was 14 weeks into her first pregnancy, had a suspected abdominal pregnancy. Both transabdominal ultrasound and an MRI indicated an ectopic pregnancy, likely originating from the right fallopian tube. A successful laparotomy and right salpingectomy were performed without complications. Rarely, as in this case, large unruptured and advanced tubal pregnancies can mimic an abdominal pregnancy, underscoring the importance of disease recognition and familiarity with uncommon image findings. An accurate diagnosis of pregnancy location is crucial for effective case management.

Performance of Serum Quad Test in Screening for Fetal Down Syndrome in a Large-Scale Unselected Population in a Developing Country.

Objective: To assess the effectiveness of Quad test in the detection of Down syndrome (DS) in routine practice among a large-scale population and to compare the effectiveness of Quad test based on the Western reference model (WM) and that based on Thai reference model (TM). Methods: Quad test was performed on 42,769 pregnancies at 14-21 weeks. The fetal risk of DS derived from Quad test was automatically computed based on WM and used in evaluating the effectiveness. Also, the fetal risk was calculated based on the TM. Results: Of 39,740 women with complete follow-ups including 74 fetuses with DS, with WM, the detection and false positive rates were 81.1% and 7.2%, respectively, whereas the detection and false positive rates with TM were 87.8%, and 6.8%, respectively. According to ROC curves, the performance of Quad test based on TM was slightly but significantly better than that based on WM (AUC of 0.959 vs. 0.940, p = 0.001). Conclusion: Quad test is highly effective in service settings and suitable for developing countries and the effectiveness is even higher when based on ethnicity-specific reference model.

Fetal Hemodynamic Response to Anemia in Early Gestation: Using Hemoglobin Bart's Disease as a Study Model.

OBJECTIVE: To assess fetal hemodynamic changes in response to anemia in early gestation, using fetal Hb Bart's disease as a study model. METHODS: A prospective study was conducted on pregnancies at risk for fetal Hb Bart's disease at 12-14 weeks of gestation. Fetal hemodynamics were comprehensively assessed by 2D ultrasound, Doppler velocity, and cardio-STIC just prior to the invasive procedure for diagnosis. The various hemodynamic parameters of the affected and unaffected fetuses were compared. RESULTS: Of 56 fetuses at risk, 17 had Hb Bart's disease and 39 were unaffected. The right and combined ventricular cardiac outputs (CO) were significantly higher in the affected fetuses (0.993 vs. 1.358; p < 0.001 and 1.010 vs. 1.236; p < 0.001, respectively), whereas the left CO tended to be higher but not significantly (1.027 vs. 1.113; p = 0.058). Cardiac dimensions, middle-cerebral artery peak systolic velocity, Tei index, and isovolemic contraction time were significantly increased, while the global sphericity index was significantly decreased. Interestingly, cardiac preload, ventricular wall thickness, shortening fraction, isovolemic relaxation time, and fetal heart rate were unchanged. Four fetuses had hydropic changes, but all cardiac functions were normal. CONCLUSION: Fetal anemia induces hypervolemia and increases cardiac output to meet the tissue oxygen requirement, resulting in an increase in size without hypertrophy, volume load without pressure load, and a decrease in the globular sphericity index. The heart works very well but works harder, especially systolic ventricular load. Hydrops fetalis due to anemia appears not to be caused by heart failure as previously believed but rather by volume load with high vascular permeability at least in early pregnancy.

Noninvasive Prenatal Diagnosis of Beta-Thalassemia Disease by Using Digital PCR Analysis of Cell-Free Fetal DNA in Maternal Plasma.

INTRODUCTION: Prenatal diagnosis of thalassemia disease was usually based on invasive technique. Noninvasive diagnosis using cell-free fetal DNA (cff-DNA) was described with various laboratory techniques. The aim of this study was to identify the performance of dPCR for analyzing cff-DNA in maternal plasma to diagnose fetal beta-thalassemia diseases. METHODS: Thirty-five couples at risk of fetal beta-thalassemia disease caused by four common mutations of HBB were enrolled at 12-18 weeks. The dPCR assay was designed to detect and quantify paternally inherited beta-thalassemia allele (PIB) and maternally inherited beta-thalassemia allele (MIB) from cff-DNA in maternal plasma. RESULTS: Of 29 couples with different paternal/maternal mutations, all cases who inherited paternal mutation had detectable PIB-M. The MIB-mutant/wild-type (MIB-M/MIB-N) ratio in the mothers whose fetuses did not inherit maternal mutation was 0.87 ± 0.07 which was significantly lower than that of the mothers whose fetuses inherited maternal mutation, 1.01 ± 0.05. The sensitivity and specificity of MIB-M/MIB-N ratio >0.95 in predicting fetus inheriting maternal mutation were 100 and 92.3%, respectively. In four couples with same paternal/maternal mutation, IB-M/IB-N ratio of >0.95 correctly predicted the presence of an inheritance of at least one beta-thalassemia allele. In two couples with paternal Hb E/beta-thalassemia, the presence of PIB-M and the MIB-M/MIB-N ratio of >0.95 correctly predicted the presence of paternal/maternal mutations, respectively. CONCLUSIONS: The method of analyzing cff-DNA in maternal plasma by dPCR is efficient for prenatal diagnosis of beta-thalassemia.

Outcomes of pregnancies complicated by haemoglobin H-constant spring and deletional haemoglobin H disease: A retrospective cohort study.

The objective of the study was to compare the maternal and foetal outcomes of pregnancies complicated by Hb H-constant spring (HbH-CS) disease/deletional HbH (HbH-del) disease and low-risk pregnancies. A retrospective cohort research was undertaken on singleton pregnancies with Hb H-CS and Hb H-del diseases. The controls were randomly selected with a control-to-case ratio of 10:1. A total of 55 cases of HbH-CS disease, 231 cases of HbH-del disease and 2860 controls were compared. The mean gestational age at delivery and birthweight were significantly lower in the HbH-CS group than in the HbH-del and control groups. The clinical course of Hb H-CS was more severe than that of HbH-del disease. The rates of preterm birth, foetal growth restriction and low birthweight were significantly increased in the HbH-CS and Hb H-del groups. These rates were significantly greater in the HbH-CS group than in the H-del group. The maternal outcomes were not significantly different among the three groups. In conclusion, pregnancy worsens the course of HbH disease, more noticeably in HbH-CS disease. Hb H disease significantly increases the risk of adverse foetal outcomes, more noticeably in the HbH-CS group. Pregnancy is relatively safe for women with HbH disease.

Prenatal Sonographic Features of Ring Chromosome 15: A Case Report and Literature Review.

Ring chromosome 15, a rare genetic disease, is very rarely prenatally diagnosed. We present a unique case of fetal ring chromosome 15 with ultrasound findings at 32 weeks of gestation including congenital diaphragmatic hernia, hypoplasia of the aorta with persistent left SVC, growth restriction, clubfeet and scoliosis. We also performed an analytical literature review of prenatal sonographic findings of the disease. This review suggests that ring chromosome 15 has a relatively specific sonographic pattern that could facilitate early detection. The specific sonographic features of ring chromosome 15 include fetal growth restriction, congenital diaphragmatic hernia, abnormal limb postures, cardiac defects, low-set ears and other less frequent, non-specific anomalies that can be identified in more than 50% of cases.

Prenatal Sonographic Features of Cri-du-Chat Syndrome: A Case Report and Analytical Literature Review.

Cri-du-Chat syndrome (CdCS) is a rare but serious genetic disorder. Most cases occur de novo, without specific risk factors as an indication of invasive prenatal diagnosis. Moreover, no specific ultrasound findings have been reported to facilitate early detection. This study presents a case of CdCS with fetal ultrasound findings of cerebellar hypoplasia and peri-membranous ventricular septal defect (VSD), which are consistent with previous reports, as well as coarctation of the aorta and hypercoiling cord, which have never been described in CdCS before. Additionally, we performed an analytical literature review to identify the sonographic pattern facilitating prenatal diagnosis. Based on the review of 47 reported cases, most CdCS fetuses (87.2%) had ultrasound characteristics: cerebellar hypoplasia (29.8%), followed by cardiac abnormalities (19.1%), hydrops fetalis/fluid collection (17.0%), ventriculomegaly (14.9%), choroid plexus cyst (12.8%) and nasal bone hypoplasia (12.8%). Increased nuchal translucency/nuchal fold thickness was also common. This is the first study providing a fetal sonographic pattern of CdCS that may facilitate early diagnosis.

Fetal heart rate tracing interpretation in cases of fetal heart block: A case series.

Simple assessment of FHR baseline variability can differentiate second-degree heart block (SHB) from complete heart block (CHB). In cases of SHB, antepartum NST can be reliably used for fetal surveillance. Intrapartum assessment of FHR variability and accelerations is useful to select cases for safe vaginal delivery.

Cardiac rhabdomyoma as a possible new prenatal sonographic feature of Prader-Willi syndrome.

We describe a unique case of a pregnancy with fetal Prader-Willi syndrome (PWS). A 40-year-old pregnant woman prenatally presented with polyhydramnios, decreased fetal movements, fetal growth restriction with normal Doppler study, and fetal cardiac rhabdomyoma, a possible new sonographic markers for PWS, at 31 weeks of gestation. The newborn had hypotonia and feeding difficulty. Molecular genetic study showed a normal copy number of the 15q11.2-q13.1 chromosomal region but hypermethylation pattern of this region, indicating PWS. Other than the combination of polyhydramnios, fetal growth restriction, and decreased fetal movements, cardiac rhabdomyoma was detected and possibly associated with PWS. In conclusion, PWS should be listed in differential diagnoses if fetuses having the following perinatal factors: polyhydramnios, decreased fetal movements, and growth restriction. Finally, cardiac rhabdomyoma, observed in this case, might possibly be associated with PWS, although further studies to confirm are needed.

Comparison of the Performances of Middle Cerebral Artery Peak Systolic Velocity and Cardiothoracic Diameter Ratio in Predicting Fetal Anemia: Using Fetal Hemoglobin Bart's Disease as a Study Model.

OBJECTIVE: The aim of the study was to compare the performances of cardiothoracic diameter ratio (CTR) and middle cerebral artery peak systolic velocity (MCA-PSV) in predicting fetal hemoglobin (Hb) Bart's disease and identify the best CTR cut-off for each gestational period. METHODS: Pregnancies at risk of fetal Hb Bart's disease (gestational ages of 12-36 weeks) were prospectively recruited to undergo ultrasound examination. The measurements of CTR and MCA-PSV were performed and recorded before invasive diagnosis. RESULTS: During the study period (2005-2019), a total of 1,717 pregnancies at risk of fetal Hb Bart's disease met the inclusion criteria and were available for analysis, including 329 (19.2%) fetuses with Hb Bart's disease. The mean gestational age at the time of diagnosis was 19.30 ± 5.6 weeks, ranging from 12 to 36 weeks. The overall performance of CTR Z-scores is superior to that of MCA-PSV multiple of median (MoM) values; area under curve of 0.866 versus 0.711, p value <0.001. The diagnostic indices of CTR and MCA-PSV are increased with gestational age. Based on receiver operating characteristic curves of CTR Z-scores, the best cut-off points of CTR at 12-14, 15-17, 18-20, 21-23, and ≥24 weeks are 0.48, 0.49, 0.50, 0.51, and 0.54, respectively. The best cut-off of MCA-PSV is 1.3 MoM, giving the best performance at 21-23 weeks with a sensitivity of 91.8% and specificity of 85.5%. CONCLUSION: The performance of CTR is much better than MCA-PSV in predicting fetal anemia caused by Hb Bart's disease. Nevertheless, whether this can be reproduced in anemia due to other causes, like isoimmunization, is yet to be explored.

Prenatal Sonographic and Molecular Genetic Diagnosis of Popliteal Pterygium Syndrome.

Popliteal pterygium syndrome (PPS) is an extremely rare autosomal dominant disorder, characterized by the cleft palate with or without cleft lip, limbs abnormalities with highly characteristic features of popliteal webbing, syndactyly, and genital abnormalities and nail anomalies. Prenatal diagnosis of PPS has been extremely rare. We describe a unique case of fetal PPS at 20 weeks of gestation. The diagnosis of PPS was based on the ultrasound findings of bilateral popliteal webbings, extending from posterior aspects of the upper thighs through the lower legs, resulting in restriction in knee extension, bilateral equinovarus feet with syndactyly, ambiguous genitalia and the grooved lip. Anatomical structures were otherwise normal. Trio whole-exome sequencing revealed a de novo heterozygous IRF6 gene mutation in the fetus, confirming the diagnosis with PPS. In conclusion, popliteal webbing or combination of facial cleft or cleft variants and bilateral abnormal postures of the lower limbs is suggestive of PPS and genetic diagnosis should be warranted.

Fetal Hemodynamic Responses to Arterial Occlusion of Acardiac Twins.

The objective of this study was to comprehensively assess fetal hemodynamic adaptions to occlusive procedures. Twin pregnancies complicated with acardiac twin and hydrops fetalis of the pump twin were recruited. The occlusive procedures - either alcoholization, radiofrequency ablation, coil embolization or occlusive glue - were performed under ultrasound guidance. Various hemodynamic parameters were assessed before, shortly after, then every 6 h for 48 h and 2-4 weeks after the procedures. Seven pregnancies were recruited. The median (range) gestational age of intervention was 21 (17-26) weeks of gestation. Before the procedures, all cases showed normal cardiac function. Just after the procedures, all cases showed an increase in Tei index and isovolumic relaxation time but returned to preocclusion levels within 6-48 h, except for two cases that were persistently high. Increased preload and poor shortening fraction were observed in two cases, leading to heart failure, with one recovery and one death in utero. Five out of the seven cases got through the critical period with a gradual return to normal hemodynamics, ending with the disappearance of hydrops and successful outcomes. It was concluded that the occlusive procedure could aggravate the overworked heart, leading to heart failure. Preocclusion preload index and Tei index may predict risk of heart failure due to the occlusion. This small series strongly suggests that the occlusion should be performed before the deterioration of cardiac function.

First trimester genetic sonogram for screening fetal Down syndrome: A population-based study.

OBJECTIVE: To evaluate the performance of first trimester sonomarkers in the detection of fetal Down syndrome among Thai pregnant women. MATERIALS AND METHODS: Pregnant women at 11-13+6 weeks' gestation underwent ultrasound examination for assessment of nuchal translucency (NT), nasal bone (NB), tricuspid regurgitation (TR), and abnormal ductus venosus (aDV) Doppler waveforms. The women were followed up for final outcomes. Fetal abnormalities other than trisomy 21 were excluded. The performances of each sonomarker and their combinations in predicting fetal Down syndrome were calculated. RESULTS: A total of 7820 pregnant women meeting the inclusion criteria were available for analysis, including 20 cases with fetal Down syndrome and 7800 unaffected cases. Of the four sonomarkers, NT, as a single sonomarker, had the highest detection rate (55.0% at a false positive rate of about 5%), whereas the remaining single sonomarkers had low detection rate (15-20%). The combination of all sonomarkers had the highest detection rate of 70% but the false positive rate was as high as 10.8%. The combination of NT and NB had a detection rate of 60% with an acceptable false positive rate of 6.9%, whereas the other combinations yielded relatively high false positive rates. CONCLUSION: The first trimester genetic sonogram in screening for Down syndrome among Asian women is acceptably effective and may be offered to some selected groups of the population. NT is the best sonomarker with a detection rate of 55% at 5% false positive rate and its combination with NB can improve performance with minimal increase in false positive rate.

Pregnancy Outcomes among Women with Intermittent Asthma: A Retrospective Cohort Study.

BACKGROUND: It is already known that asthma strongly increases risks of poor pregnancy outcomes. We wonder whether intermittent asthma, the least severe form but accounting for the majority of cases, increases such adverse outcomes or not. Therefore, we conducted this study to compare adverse pregnancy outcomes between pregnancies with intermittent asthma and low-risk pregnancies (controls). METHODS: The full medical records of pregnancies with intermittent asthma were comprehensively reviewed and low-risk pregnancies were randomly recruited as controls with a ratio of 10:1. The obstetric outcomes were compared between both groups, and the outcomes in the active subgroup of intermittent asthma (defined as at least one asthmatic attack during pregnancy) were also compared with the controls. RESULTS: Of 364 study cases and 3640 controls, the rates of poor outcomes (preterm birth, preeclampsia, fetal growth restriction etc.) were not significantly different. However, cases with active disease slightly, but significantly, increased the risk of low birth weight. Moreover, mean gestational age was significantly lower in the study group. CONCLUSIONS: A new insight gained from this study is that intermittent asthma is not associated with poor pregnancy outcomes, but cases with asthmatic attack during pregnancy tended to increase the risk of preterm birth and low birth weight. This information is important for counseling and the planning of antepartum management.

Ethnicity-Specific Normative Models of Quadruple Test as a Screening Test for Down Syndrome.

Background and Objectives: To establish normative models for median levels of serum biomarkers of the second trimester quad test (alpha-fetoprotein: AFP; free beta-human gonadotropins: hCG; inhibin-A; and unconjugated estriol: uE3) specific to Thai women and to compare multiples of the median (MoMs) derived from ethnicity-specific models and those derived from Caucasian models with ethnic correction. Materials and Methods: A cross-sectional study was undertaken in a tertiary, medical teaching center among low-risk pregnant Thai women between 14 and 21 weeks of gestation to measure the levels of the four serum biomarkers. The measured values of each biomarker were analyzed using the multivariable factorial polynomial technique for quantile regression as a function of gestational age and maternal weight. Results: The Thai-specific normative models for the four biomarkers were generated and available for use. The MoMs of all individuals generated from our models were significantly different from conventional (Caucasian) models with ethnic correction (Wilcoxon signed-rank test; p < 0.0001 for all biomarkers). The MoMs of AFP and hCG from both methods were in agreement, but those from Thai-specific models were significantly higher. However, those of inhibin-A and uE3 were markedly different and ethnic correction was unlikely to be useful. Conclusions: The Thai-specific normative models of the quad test as a function of gestational age and maternal weight were constructed using multivariable factorial polynomial models, better than simple quantile regression or log-linear regression used in earlier decades. The analysis of MoMs supports the use of ethnicity-specific models instead of Caucasian models with ethnic correction.

Fetal Beckwith-Wiedemann syndrome associated with abnormal quad test, placental mesenchymal dysplasia and HELLP syndrome.

We describe a unique case of Beckwith-Wiedemann syndrome (BWS). A 29-year-old woman with ultrasound and clinical findings, specific to BWS is described. Important insights gained from this study are as follows: (1) quad test may be very useful to increase awareness of BWS. This is the first report, which demonstrated that elevated inhibin-A is related to BWS. Unexplained elevation of serum biomarkers, especially all the four markers, should raise awareness of BWS. (2) Early provisional diagnosis in this case was based on the findings of omphalocele, placental mesenchymal dysplasia and abnormal quad test. (3) Follow-up scans are important for late-occurring supportive findings, such as macroglossia, ear abnormalities and visceromegaly. (4) BWS is strongly associated with preeclampsia, which tended to be more severe and of earlier-onset. (5) Molecular genetic analysis is helpful, but not always necessary in cases of fulfilment of clinical criteria like in this case.

New genetic and clinical evidence associated with fetal Beckwith-Wiedemann syndrome.

Early detection of Beckwith-Wiedemann syndrome (BWS) is very important since it is very useful regarding counseling of parents concerning the risk of developing embryonic tumors, selection of the mode of delivery due to potential adrenal cysts that might bleed during labor, prevention of neonatal hypoglycemia and even options of pregnancy termination in non-viable fetuses. This report describes the prenatal classic sonographic triad of fetal BWS (omphalocele, macrosomia, macroglossia) and other supporting findings (hepatomegaly, adrenal enlargement) as well as additional postnatal evidence. Also, it demonstrates new molecular genetic evidence potentially associated with the disease (the presence of a novel heterozygous c.358G>T variant of the CDKN1C gene). Importantly, we provide new evidence indicating that elevated levels of the four serum biomarkers (alpha-fetoprotein, beta-human gonadotropin, unconjugated estriol, and inhibin-A) in late first or early second trimester might be strongly suggestive of BWS which may facilitate early detection especially in cases of no obvious anomaly. In conclusion, this study emphasizes on early detection of BWS as early as at 14 weeks of gestation, based on the abnormal rise of the four serum biomarkers together with omphalocele. To the best of our knowledge, this is the earliest prenatal detection of BWS ever reported. Finally, we provide new molecular genetic evidence that is, potentially associated with BWS.

May-Thurner Syndrome Is Aggravated by Pregnancy.

This study aims to emphasize that asymptomatic patients with undiagnosed and asymptomatic May-Thurner syndrome (MTS) may firstly develop severe compression during pregnancy. A 40-year-old woman, G1P0, at 22 weeks of twin gestation presented with left lower extremity edema and pain. One twin was structurally normal while the other had bilateral renal agenesis with oligohydramnios. Magnetic resonance venography (MRV) revealed severe compression of the left iliac vein by the right iliac artery without evidence of deep vein thrombosis (DVT). Conservative treatment with anticoagulant prophylaxis was instituted throughout the rest of pregnancy and postpartum period. She was also complicated with severe pre-eclampsia, a cesarean section was performed due to a prolapsed cord at 27 weeks of gestation, and she gave birth to a surviving baby weighing 1100 g. In conclusion, this case report provides evidence that pregnancy can disclose a subtle May-Thurner anatomy to be symptomatic without DVT. Successful pregnancy outcomes could be achieved with conservative treatment and anticoagulant prophylaxis.

Prenatal Sonographic Features of CHARGE Syndrome.

CHARGE syndrome is a rare autosomal dominant disorder, associated with coloboma (C), heart defects (H), choanal atresia (A), retardation of growth and/or central nervous system (R), genitourinary anomalies (G) and ear abnormalities (E). Prenatal diagnosis of the syndrome is very rare but may be suspected when a combination of such abnormalities is identified. We describe a prenatally suspected case of CHARGE syndrome due to unique findings of cardiac defects (DORV) in combination with minor clues, including a structurally malformed ear with persistent non-response to an acoustic stimulation (which has never been prenatally described elsewhere), renal malrotation and growth restriction. Postnatal diagnosis was made based on confirmation of the prenatal findings and additional specific findings of bilateral coloboma, choanal atresia and ear canal stenosis. Finally, molecular genetic testing by whole exome sequencing of the neonate and her parents revealed a novel de novo heterozygous frameshift c.3506_3509dup variant in the CHD7 gene, confirming the clinical diagnosis of CHARGE syndrome. In conclusion, we describe unique prenatal features of CHARGE syndrome. Educationally, this is one of the rare examples of CHARGE syndrome, comprising all of the six specific anomalies as originally described; it is also supported by the identification of a specific genetic mutation. The identified genetic variant has never been previously reported, thereby expanding the mutational spectrum of CHD7. Finally, this case can inspire prenatal sonographers to increase awareness of subtle or minor abnormalities as genetic sonomarkers.