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

Comparing three cardiothoracic ratio measurement techniques and creating multivariable scoring system to predict Bart's hydrops fetalis at 17-22 weeks' gestation

To assess the diagnostic performance of three cardiothoracic (CT) ratio techniques, including diameter, circumference, and area, for predicting hemoglobin (Hb) Bart's disease between 17 and 22 weeks' gestation, and to create a multivariable scoring system using multiple ultrasound markers. Before invasive testing, three CT ratio techniques and other ultrasound markers were obtained in 151 singleton pregnancies at risk of Hb Bart's disease. CT diameter ratio demonstrated the highest sensitivity among the other techniques. Significant predictors included CT diameter ratio > 0.5, middle cerebral artery-peak systolic velocity (MCA-PSV) > 1.5 multiples of the median, and placental thickness > 3 cm. MCA-PSV exhibited the highest sensitivity (97.8%) in predicting affected fetuses. A multivariable scoring achieved excellent sensitivity (100%) and specificity (84.9%) for disease prediction. CT diameter ratio exhibited slightly outperforming the other techniques. Increased MCA-PSV was the most valuable ultrasound marker. Multivariable scoring surpassed single-parameter analysis in predictive capabilities.

Ten years' experience in prenatal diagnosis of α-thalassemia in a municipal hospital and retrospective analysis of ultrasonic abnormalities

OBJECTIVE

This study reviewed and analyzed the prenatal diagnosis experience of thalassemia in our center over the past decade and the abnormal ultrasonic characteristics of fetuses with hemoglobin (Hb) Bart's hydrops fetalis.

METHODS

Pregnant women and their partners who tested positive for α0-thalassemia or were diagnosed with thalassemia intermedia (HbH diseases) underwent genetic counseling, and a prenatal diagnostic procedure for α-thalassemia was recommended. Ultrasonography was performed before prenatal diagnosis.

RESULTS

Invasive prenatal α-thalassemia diagnosis and ultrasonography were performed in 1049 patients at risk for Hb Bart's hydrops fetalis syndrome at our hospital from 2012 to 2021. Chorionic villus sampling (CVS) was performed in 58 cases (5.5%), amniocentesis in 902 cases (86%), and cordocentesis in 89 cases (8.5%). Hb Bart's hydrops fetalis syndrome was diagnosed in 280 fetuses. The most common body cavity effusion was pericardial effusion, ascites, and fetal systemic edema.

CONCLUSIONS

The extensive experience at our center shows that carrier screening, molecular diagnostics, genetic counseling, and prenatal diagnosis are effective measures to prevent Hb Bart's hydrops fetalis syndrome. The ultrasonographic abnormalities in fetuses with Hb Bart's hydrops are mainly caused by an increase in cardiac output, which leads to the body cavity effusion from various organs.

Fetal Cardiac Inflow Characteristics in Response to Fetal Anemia: Based on Fetal Hemoglobin Bart's Disease at Mid-Pregnancy

OBJECTIVES

To identify the inflow (filling time fraction [FTF] and E/A ratio) characteristics of fetuses with anemia, and to evaluate the performance of the inflow markers in predicting the affected fetuses.

METHODS

Fetuses at risk of hemoglobin (Hb) Bart's disease at 17-22 weeks were prospectively recruited to undergo echocardiography before diagnostic cordocentesis. Cardiac Doppler images were digitally stored for off-line blinded measurements of FTF and E/A ratio.

RESULTS

A total of 428 fetuses at risk of Hb Bart's disease were analyzed, including 88 affected fetuses (20.6%). The mean gestational age at the time of diagnosis was 19.43 ± 1.5 weeks. The FTFs in both sides were significantly lower in the affected fetuses, whereas the E/A ratios of both sides were significantly higher in the affected group. According to the receiver operating characteristic curves, the performance of the FTF of the right side in predicting affected fetuses was slightly better than that of the left side (area under curve: 0.707 versus 0.680, P < .001). Likewise, the performance of the E/A ratio of the tricuspid valve was slightly better than that of the mitral valve. Also, FTF was superior to E/A ratio in predicting the affected fetuses.

CONCLUSIONS

New insights leading to a better understanding of the fetal cardiac response to anemia are: 1) the FTFs in both sides were significantly decreased, suggesting some degree of diastolic ventricular dysfunction; 2) the E/A ratios of both sides were significantly increased, indicating volume load; and 3) The inflow parameters may be useful as a new predictor of fetal anemia, especially among pregnancies at risk.

Prenatal Diagnosis of Fetal Heart Failure

Fetal heart failure (FHF) is a condition of inability of the fetal heart to deliver adequate blood flow for tissue perfusion in various organs, especially the brain, heart, liver and kidneys. FHF is associated with inadequate cardiac output, which is commonly encountered as the final outcome of several disorders and may lead to intrauterine fetal death or severe morbidity. Fetal echocardiography plays an important role in diagnosis of FHF as well as of the underlying causes. The main findings supporting the diagnosis of FHF include various signs of cardiac dysfunction, such as cardiomegaly, poor contractility, low cardiac output, increased central venous pressures, hydropic signs, and the findings of specific underlying disorders. This review will present a summary of the pathophysiology of fetal cardiac failure and practical points in fetal echocardiography for diagnosis of FHF, focusing on essential diagnostic techniques used in daily practice for evaluation of fetal cardiac function, such as myocardial performance index, arterial and systemic venous Doppler waveforms, shortening fraction, and cardiovascular profile score (CVPs), a combination of five echocardiographic markers indicative of fetal cardiovascular health. The common causes of FHF are reviewed and updated in detail, including fetal dysrhythmia, fetal anemia (e.g., alpha-thalassemia, parvovirus B19 infection, and twin anemia-polycythemia sequence), non-anemic volume load (e.g., twin-to-twin transfusion, arteriovenous malformations, and sacrococcygeal teratoma, etc.), increased afterload (intrauterine growth restriction and outflow tract obstruction, such as critical aortic stenosis), intrinsic myocardial disease (cardiomyopathies), congenital heart defects (Ebstein anomaly, hypoplastic heart, pulmonary stenosis with intact interventricular septum, etc.) and external cardiac compression. Understanding the pathophysiology and clinical courses of various etiologies of FHF can help physicians make prenatal diagnoses and serve as a guide for counseling, surveillance and management.

The Accelerated Right Ventricular Failure in Fetal Anemia in the Presence of Restrictive Foramen Ovale

Objective: To describe serious hemodynamic changes secondary to anemia in the case of restrictive foramen ovale (FO). Case: A 43-year-old pregnant woman, G4P0030, underwent fetal echocardiography at 35 weeks of gestation and was found to have (1) restrictive FO; (2) poor right ventricular function; (3) unbalanced hemodynamics; (4) fetal anemia (high MCA-PSV and hepatosplenomegaly). Acid-elution test indicated feto-maternal hemorrhage. Cesarean section was performed for postnatal blood transfusion. Nevertheless, the newborn developed heart failure and died after partial blood exchanges. Conclusions: Insights gained from this study are as follows: (1) Restrictive FO in structurally normal hearts can modify fetal response to anemia differently, by unequally distributing blood volume, leading to much more deteriorating right ventricular function. (2) To make decisions for intrauterine or extrauterine treatment in cases of anemia-associated heart failure, several factors must be taken into account such as gestational age, fetal cardiac function, and placental function. Because of the hyperdynamic state of newborns immediately after birth, delivery can deteriorate the compromised heart to irreversible failure. Intrauterine transfusion for a well-prepared heart just before delivery may be the best option since the baby should be well oxygenated at the time of delivery.