Epidemiology, Genetics and Epigenetics of Congenital Heart Diseases in Twins

Cardiac findings in newborn twins

AIMS

To evaluate cardiac findings in newborn twins from the general population and investigate if newborn twins may require systematic evaluation of cardiac parameters.

METHODS

Prospective cohort study of newborns with cardiac evaluation performed during the first month of life. Cardiac findings were compared 1:3 with matched singletons.

RESULTS

We included 412 newborn twins (16% monochorionic; 50% boys) and 1236 singletons. Comparing cardiac findings showed twins had an increased prevalence of non-severe structural heart disease (most common: ventricular septal defects in both groups), thinner left ventricular posterior wall in diastole (LVPWd; 1.82 vs. 1.87 mm, p = 0.02), smaller diameter of the left atrium (10.6 vs. 11.1 mm, p = 0.04), higher heart rate (148 vs. 144 bpm, p = 0.04), more left-shifted QRS axis (106 vs. 111°, p < 0.001), and lower maximum R-wave amplitude in V1 (927 vs. 1015 μV, p = 0.02) compared to singletons. After multifactorial adjustment for potential confounders, the effect of twinning on cardiac parameters persisted only for LVPWd (p < 0.05).

CONCLUSION

Despite contemporary surveillance, we found an increased prevalence of non-severe structural heart disease in a population-based cohort of newborn twins. However, the effect of twinning on cardiac parameters was modest and generally did not persist after correction for likely confounding factors.

Ankyloglossia in Monochorionic Diamniotic and Dichorionic Diamniotic Twins: A Cross-Sectional Study

Objective: To determine the prevalence of ankyloglossia in diamniotic monochorionic and diamniotic dichorionic twins, as well as to verify the relationship between gender and type of pregnancy. Study Design: A cross-sectional observational study, carried out with 52 pairs of dichorionic/diamniotic twins and 49 monochorionic/diamniotic pairs. The data collection was carried out through the analysis of medical records and the results of the Neonatal Screening of the Tongue Frenulum Assessment Protocol in Babies, and corresponded to the period of 2 years (2020-2022). Statistical analysis of data was performed, considering the significance value of 5%. The study was approved by the Human Research Ethics Committee of the institution. Results: The statistical analysis of multiple logistic regression between the two groups of twins (Mono/Di and Di/Di) according to the socioeconomic, demographic, and clinical-epidemiological profile was statistically significant for some variables. The prevalence of ankyloglossia, according to the type of twin pregnancy, showed a statistically significant difference. There was no statistical difference in relation to sex and ankyloglossia, or between couples diagnosed with ankyloglossia according to the type of pregnancy. Conclusion: Monochorionic/diamniotic twins had a higher prevalence of ankyloglossia, regardless of gender.

Application of Semiautomatic Fetal Intelligent Navigation Echocardiography (FINE) in Twin Pregnancies: Half the Work or Twice the Effort?

OBJECTIVE

To assess the performance of fetal intelligent navigation echocardiography (FINE, 5D Heart™) for automated volumetric investigation of the fetal heart in twin pregnancies.

METHODS

Three hundred twenty-eight twin fetuses underwent fetal echocardiography in the second and third trimesters. Spatiotemporal image correlation (STIC) volumes were obtained for a volumetric investigation. The volumes were analyzed using the FINE software, and the data were investigated regarding image quality and many properly reconstructed planes.

RESULTS

Three hundred and eight volumes underwent final analysis. 55.8% of the included pregnancies were dichorionic twin pregnancies, and 44.2% were monochorionic twin pregnancies. The mean gestational age (GA) was 22.1 weeks, and the mean maternal BMI was 27.3 kg/m². The STIC-volume acquisition was successful in 100.0% and 95.5% of cases. The overall depiction rates of FINE were 96.5% (twin 1) and 94.7% (twin 2), respectively (p = 0.0849, not significant). In 95.9% (twin 1) and 93.9% (twin 2), at least 7 planes were reconstructed properly (p = 0.6056, not significant).

CONCLUSION

Our results indicate that the FINE technique used in twin pregnancies is reliable. No significant difference between the depiction rates of twin 1 and twin 2 could be detected. In addition, the depiction rates are as high as those derived from singleton pregnancies. Due to the challenges of fetal echocardiography in twin pregnancies (i.e., greater rates of cardiac anomaly and more difficult scans), the FINE technique might be a valuable tool to improve the quality of medical care in those pregnancies.

A Pilot Study Characterizing Flow Patterns in the Thoracic Aorta of Patients With Connective Tissue Disease: Comparison to Age- and Gender-Matched Controls via Fluid Structure Interaction

Prior computational and imaging studies described changes in flow patterns for patients with Marfan syndrome, but studies are lacking for related populations. This pilot study addresses this void by characterizing wall shear stress (WSS) indices for patients with Loeys-Dietz and undifferentiated connective tissue diseases. Using aortic valve-based velocity profiles from magnetic resonance imaging as input to patient-specific fluid structure interaction (FSI) models, we determined local flow patterns throughout the aorta for four patients with various connective tissue diseases (Loeys-Dietz with the native aorta, connective tissue disease of unclear etiology with native aorta in female and male patients, and an untreated patient with Marfan syndrome, as well as twin patients with Marfan syndrome who underwent valve-sparing root replacement). FSI simulations used physiological boundary conditions and material properties to replicate available measurements. Time-averaged WSS (TAWSS) and oscillatory shear index (OSI) results are presented with localized comparison to age- and gender-matched control participants. Ascending aortic dimensions were greater in almost all patients with connective tissue diseases relative to their respective control. Differences in TAWSS and OSI were driven by local morphological differences and cardiac output. For example, the model for one twin had a more pronounced proximal descending aorta in the vicinity of the ductus ligamentum that impacted WSS indices relative to the other. We are optimistic that the results of this study can serve as a foundation for larger future studies on the connective tissue disorders presented in this article.