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.

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.

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.

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.

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.

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.

Comparison of pregnancy outcomes after second trimester amniocentesis between procedures performed by experts and non-experts.

OBJECTIVES: To compare the rate of fetal loss in pregnancy after second trimester amniocentesis between procedures performed by experts and non-experts and to assess other pregnancy complications as secondary outcomes. METHODS: A retrospective cohort study was performed on singleton pregnancies that underwent mid-trimester amniocenteses in a single institution. The fetal loss rates of procedures performed by experts and non-experts were collected and analyzed. Other adverse pregnancy outcomes were also examined. RESULTS: In total, 14,450 amniocenteses were performed during the study period. These included 11,357 (78.6%) procedures in the group expert operators and 3,093 (21.4%) procedures in the group non-expert operators. In the non-expert group, the fetal loss rate was slightly increased but not significantly (p=0.24).In addition, the higher number of spontaneous abortions was associated with blood-stained amniotic fluid sample (p<0.001; RR=9.28). Multiple needle insertions also increased in the non-expert group significantly. However, no difference in pregnancy outcomes was found between in single and multiple needle insertions. CONCLUSIONS: The amniocentesis procedures performed by the non-experts was not increase the fetal loss rate. However, the other adverse pregnancy outcomes, including preterm birth, low birth weight and fetal growth restriction were significantly increased in the non-expert group.

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.

Fetal hydrometrocolpos with pre-axial mirror polydactyly as a new variant of McKusick-Kaufman syndrome.

This report describes a variant of McKusick-Kaufman syndrome presenting with a large fetal abdominal cyst of hydrometrocolpos at 37 weeks of gestation. The diagnosis was based on the ultrasound findings of a large homogeneous hypoechoic cyst (diameter of >10 cm) with incomplete septum, thickened wall, superiorly connecting to the dilated uterus, consistent with hydrometrocolpos. Additionally, pre-axial mirror polydactyly of the left foot was suspected. Postnatal examination/work-up confirmed the prenatal findings. This is the first report of prenatal diagnosis of hydrometrocolpos with complex polydactyly of mirror image pre-axial duplications containing nine toes instead of six-toe postaxial polydactyly.

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.

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.

Comparisons of pregnancy outcomes between twin pregnancies with and without second-trimester amniocentesis.

OBJECTIVE: To assess the amniocentesis-related pregnancy loss rate and preterm birth rate among twin pregnancies undergoing amniocentesis. METHODS: A retrospective cohort study was conducted at a tertiary center. The study group included twin pregnancies undergoing amniocentesis during 16 to 22 weeks of gestation. The control group was those not undergoing amniocentesis. All amniocenteses were performed by the MFM specialists. The main outcomes were the rate of pregnancy loss (before 24 weeks) and preterm birth. RESULTS: A total of 332 cases in the study group and 1188 controls were analyzed. The percentages of maternal age ≥35 years, high parity, and cases complicated with medical diseases were significantly higher in the study group. The pregnancy loss rate after the procedure tended to be higher, but not significant, in the study group (3.0% vs 2.2% P = .383). Likewise, the rate of preterm birth in the study group was higher, but not significant (70.5% vs 66.0% P = .130). Logistic regression analysis to adjust confounding factors showed no significance of amniocentesis on pregnancy loss and preterm birth. CONCLUSION: Though amniocentesis in twin pregnancies has theoretical risk of pregnancy loss, it is relatively safe when performed by maternal-fetal medicine specialists. This information is useful for counseling, especially when performed by experienced hands.

Quad test for fetal aneuploidy screening as a predictor of small-for-gestational age fetuses: a population-based study.

BACKGROUND: To identify the relationship between quadruple test for aneuploidy screening (alpha-fetoprotein: AFP; free beta-human chorionic gonadotropin: b-hCG; unconjugated estriol: uE3 and inhibin-A: IHA) and fetal growth restriction and to construct predictive models for small-for-gestational-age (SGA) fetuses. METHODS: Women who underwent quadruple test for aneuploidy were followed-up for final outcomes. The multiples of the median (MoMs) of the four biochemical markers for the SGA group and those of normal fetuses were compared. The models for predicting SGA by the individual biomarkers and their combination were constructed using binary logistic regression analysis, and their diagnostic performances in predicting SGA were determined. RESULTS: Of 10,155 eligible pregnant women, 578 (5.7%) and 9577 (94.3%) had SGA and normal growth, respectively. High levels of AFP, b-hCG and IHA but low levels of uE3 significantly increased the risk of SGA. The constructed predictive equations had predictive performance for SGA, with areas under the receiver-operated characteristic curve of 0.724, 0.655, 0.597, 0.664 and 0.754 for AFP, b-hCG, uE3, IHA, and the combination, respectively. CONCLUSION: The quad test for aneuploidy screening could also be used as a predictor of SGA, without extra-effort and extra-cost.

Z Score Reference Ranges of Fetal Cardiac Output From 12 to 40 Weeks of Pregnancy.

OBJECTIVES: To develop the Z score reference ranges of fetal cardiac output (CO) in healthy fetuses from 12 to 40 weeks of pregnancy. METHODS: A cross-sectional descriptive study was undertaken among low-risk singleton pregnancies with healthy fetuses between 12 and 40 weeks. The right ventricular cardiac output (RCO), left ventricular cardiac output (LCO), and combined cardiac output (CCO) were measured by 2-dimensional ultrasound with the Doppler velocity of the aorta and pulmonary arteries. The pregnancies were followed until delivery RESULTS: The RCO, LCO, and CCO were determined in 700 fetuses. The predictive models of the CO as a function of gestational age (GA) and biparietal diameter were identified, and the Z score reference ranges were constructed. The means and standard deviations of CO on both sides were increased with GA and biparietal diameter as power models. Nomograms for the LCO, RCO, and CCO were established (ie, RCO = 0.000148 × GA4.283034 ; SD = 0.000131 × GA4.026209 ; LCO = 0.000514 × GA3.790944 ; SD = 0.000169 × GA3.815546 ). The RCO was much more increased than the LCO with advancing GA. CONCLUSIONS: The Z score reference ranges and percentile charts of fetal CO were constructed throughout gestation with a large sample size. This may be helpful in detection of cardiac disorders, especially cardiomyopathy, cardiac anomalies, fetal anemia, and fetal growth restriction.

Comparison of the Effectiveness of Universal and Targeted Iodine Supplementation in Pregnant Women: A Randomized Controlled Trial.

OBJECTIVE: To compare the effectiveness of universal and targeted iodine supplementation strategies. METHODS: A randomized controlled trial involving low-risk Thai pregnant women was carried out. The participants were categorized into either the study group, in which iodine supplementation was varied based on median urine iodine concentration, or the control group, which received universal supplementation. Urine samples were collected before the start of treatment and at delivery. The primary outcome was iodine status after each supplementation regime. RESULTS: Two hundred and eight women were randomly categorized into 2 groups, 104 control-group participants and 104 study-group participants. Baseline iodine status in both groups was not significantly different. More than half of the pregnant women were classified as having iodine insufficiency. After supplementation, the proportions of iodine insufficiency in the control and study groups (27.9 and 33.3%, respectively; p value = 0.508) and those of excessive level (19.1 and 11.7%, respectively; p value = 0.247) were not significantly different between the 2 groups. However, iodine level above the requirement was statistically significantly higher in the control group (47.1%) compared with the study group (30.0%; p value = 0.048). CONCLUSIONS: The 2 strategies, universal and targeted supplementation, have comparable effectiveness in prevention of iodine deficiency, but the evidence suggests that targeted supplementation is better in avoiding over-supplementation.

Fetal Cardiac Remodeling in Response to Anemia: Using Hemoglobin Bart's Disease as a Study Model.

OBJECTIVE: To assess fetal cardiac remodeling in response to anemia, by comparing the fetal cardiac dimensions and global sphericity index (GSI) of normal fetuses and fetuses with anemia using fetal Hb Bart's disease as a study model. METHODS: Fetuses at risk for Hb Bart's disease undergoing cordocentesis at 18 to 22 weeks of gestation were recruited. Fetal cardiac dimensions including GSI (cardiac length to cardiac width ratio), interventricular septum thickness (IVST), left ventricular wall thickness (LVWT) and right ventricular wall thickness (RVWT) were measured. RESULTS: 215 pregnancies at risk met the inclusion criteria, including 54 affected fetuses and 161 normal fetuses. The mean GSI was significantly lower in the affected group (1.11 ±â€Š0.06 vs. 1.26 ±â€Š0.09, p-value 0.017). The GSI of the normal group was relatively constant regardless of gestational age. The IVST and LVWT tended to increase, but not significantly, in the affected group, whereas the RVWT was minimally but significantly increased. The ROC curve for GSI had an area under curve of 0.844. The best cut-off of GSI was 1.17, giving a sensitivity of 74.1 % and a specificity of 88.2 %. CONCLUSION: Fetal cardiac remodeling in response to anemia causes a marked decrease in global GSI with minimal hypertrophy as an adaption to volume overload. Importantly, GSI is a new maker for anemia and may play a role in clinical application for early detection of fetal anemia, possibly due to any cause. Additionally, GSI measurement is simple and gestational age-independent.

Early prenatal detection of anterior uterine sacculation resulting from previous cesarean sections.

Anterior uterine sacculation was diagnosed at 15 weeks of gestation in a woman with two previous cesarean sections, based on hourglass appearance of two distinct uterine segments, namely the empty upper segment and the large thinned wall lower segment containing a fetus with posteriorly attached placenta. The pregnancy developed through the bulging weakened anterior wall instead of growing toward the upper segment. Urgent hysterectomy was performed. The operative and pathological findings confirmed the prenatal ultrasound findings. This is the first report of prenatal diagnosis of sacculation due to cesarean section, which prevented the catastrophic event of uterine rupture.

Giant choledochal cyst and infantile polycystic kidneys as prenatal sonographic features of Caroli syndrome.

Caroli syndrome is a developmental disorder caused by complete or partial arrest of ductal plate remodeling, leading to dilated bile ducts along with fibrosis surrounding the portal tracts. It is most commonly associated with autosomal recessive polycystic kidney (ARPKD). We report a unique case of Caroli syndrome, diagnosed prenatally at 24 weeks of gestation in a 29-year-old Thai woman. Ultrasound findings revealed the association of a fetal giant choledochal cyst with ARPKD. Autopsy findings showed ductal plate malformation, typical of Caroli syndrome, associated with giant choledocal cyst and ARPKD.

Prenatal sonographic features of fetal mediastinal teratoma.

Mediastinal teratoma can cause severe hydrops fetalis, which worsens the effects of the mass compression on the vital mediastinal organs. A careful sonographic examination is mandatory to demonstrate the characteristic features suggestive of this congenital tumor. We describe these features at 20 weeks gestation. The most prominent finding was the heterogeneous echogenicity of a large cystic-solid mass with hyperechoic dots, seen as a part of the anterior mediastinum immediately posterior to the sternum. Additional diagnostic features included posterior displacement of the heart, low cardiac output, and hypoplasia of the normally structured heart and lungs due to the direct mass compression. These sonographic findings were confirmed at autopsy which confirmed a nonmetastatic immature teratoma. Sonography may enable accurate diagnosis of mediastinal teratoma considering the anterior location and heterogeneous appearance of the mass, posterior displacement of the heart, normal lung morphology, and compression effects on these organs.

The performance of cardio-biparietal ratio measured by 2D ultrasound in predicting fetal hemoglobin Bart disease during midpregnancy: A pilot study.

OBJECTIVE: The aim of this study was to assess the performance of cardio-biparietal ratio measured by real-time two-dimensional ultrasound in predicting hemoglobin (Hb) Bart disease among fetuses at risk. METHOD: This prospective diagnostic study recruited pregnancies at risk for Hb Bart disease at 17 to 22 weeks' gestation. Cardio-biparietal ratio and cardiothoracic ratio were measured before cordocentesis for Hb typing. The performance of the cardio-biparietal ratio and cardiothoracic ratio for identifying affected fetuses was evaluated. RESULTS: Among 72 fetuses at risk, 31 were diagnosed as affected by Hb Bart disease. By using a cutoff 0.45, cardio-biparietal ratio had a sensitivity of 83.9%, specificity of 92.7%, positive predictive value of 89.7%, and negative predictive value of 88.4%, whereas cardiothoracic ratio using cutoff 0.5 had a sensitivity of 94.3%, specificity of 65.1%, positive predictive value of 68.8%, and negative predictive value of 93.3%. CONCLUSION: Cardio-biparietal ratio is a new sonomarker to predict Hb Bart disease among fetuses at risk. This sonomarker is relatively effective and may be useful in areas of high prevalence of alpha thalassemia disease, limited number of experts in prenatal ultrasound, and difficult access to prenatal diagnosis.