Normal reference ranges for fetal cardiac function: Assessed by modified Doppler myocardial performance index (Mod MPI) in the Egyptian population

Impact of overweight and obesity in the fetal cardiac function parameters in the second and third trimesters of pregnancy

OBJECTIVE

To assess the impact of overweight and obesity in the second and third trimesters of pregnancy on fetal cardiac function parameters.

METHODS

We performed a prospective cohort study of 374 singleton pregnant women between 20w0d and 36w6d divided into three groups: 154 controls (body mass index - BMI < 25 kg/m2), 140 overweight (BMI 25-30 kg/m2) and 80 obese (BMI ≥ 30 kg/m2). Fetal left ventricular (LV) modified myocardial performance index (Mod-MPI) was calculated according to the following formula: (isovolumetric contraction time + isovolumetric relaxation time)/ejection time. Spectral tissue Doppler was used to determine LV and right ventricular (RV) myocardial performance index (MPI'), peak myocardial velocity during systole (S'), early diastole (E'), and late diastole (A').

RESULTS

We found significant differences between the groups in maternal age (p < 0.001), maternal weight (p < 0.001), BMI (p < 0.001), number of pregnancies (p < 0.001), parity (p < 0.001), gestational age (p = 0.013), and estimated fetal weight (p = 0.003). Overweight pregnant women had higher LV Mod-MPI (0.046 versus 0.044 seconds, p = 0.009) and LV MPI' (0.50 versus 0.47 seconds, p < 0.001) than the control group. Obese pregnant women had higher RV E' than control (6.82 versus 6.33 cm/sec, p = 0.008) and overweight (6.82 versus 6.46 cm/sec, p = 0.047) groups. There were no differences in 5-min APGAR score < 7, neonatal intensive care unit admission, hypoglycemia and hyperglobulinemia between the groups.

CONCLUSIONS

We observed fetal myocardial dysfunction in overweight and obese pregnant women with higher LV Mod-MPI, LV MPI' and RV E' compared to fetuses from normal weight pregnant women.

How Automated Techniques Ease Functional Assessment of the Fetal Heart: Applicability of MPI+™ for Direct Quantification of the Modified Myocardial Performance Index

(1) Objectives: In utero functional cardiac assessments using echocardiography have become increasingly important. The myocardial performance index (MPI, Tei index) is currently used to evaluate fetal cardiac anatomy, hemodynamics and function. An ultrasound examination is highly examiner-dependent, and training is of enormous significance in terms of proper application and subsequent interpretation. Future experts will progressively be guided by applications of artificial intelligence, on whose algorithms prenatal diagnostics will rely on increasingly. The objective of this study was to demonstrate the feasibility of whether less experienced operators might benefit from an automated tool of MPI quantification in the clinical routine. (2) Methods: In this study, a total of 85 unselected, normal, singleton, second- and third-trimester fetuses with normofrequent heart rates were examined by a targeted ultrasound. The modified right ventricular MPI (RV-Mod-MPI) was measured, both by a beginner and an expert. A calculation was performed semiautomatically using a Samsung Hera W10 ultrasound system (MPI+™, Samsung Healthcare, Gangwon-do, South Korea) by taking separate recordings of the right ventricle's in- and outflow using a conventional pulsed-wave Doppler. The measured RV-Mod-MPI values were assigned to gestational age. The data were compared between the beginner and the expert using a Bland-Altman plot to test the agreement between both operators, and the intraclass correlation was calculated. (3) Results: The mean maternal age was 32 years (19 to 42 years), and the mean maternal pre-pregnancy body mass index was 24.85 kg/m² (ranging from 17.11 to 44.08 kg/m²). The mean gestational age was 24.44 weeks (ranging from 19.29 to 36.43 weeks). The averaged RV-Mod-MPI value of the beginner was 0.513 ± 0.09, and that of the expert was 0.501 ± 0.08. Between the beginner and the expert, the measured RV-Mod-MPI values indicated a similar distribution. The statistical analysis showed a Bland-Altman bias of 0.01136 (95% limits of agreement from -0.1674 to 0.1902). The intraclass correlation coefficient was 0.624 (95% confidence interval from 0.423 to 0.755). (4) Conclusions: For experts as well as for beginners, the RV-Mod-MPI is an excellent diagnostic tool for the assessment of fetal cardiac function. It is a time-saving procedure, offers an intuitive user interface and is easy to learn. There is no additional effort required to measure the RV-Mod-MPI. In times of reduced resources, such assisted systems of fast value acquisition represent clear added value. The establishment of the automated measurement of the RV-Mod-MPI in clinical routine should be the next level in cardiac function assessment.

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.

Maternal obesity in pregnancy and children’s cardiac function and structure: A systematic review and meta-analysis of evidence from human studies

The prevalence of obesity is increasing worldwide. Experimental animal studies demonstrate that maternal obesity during pregnancy directly affects cardiac structure and function in their offspring, which could contribute to their increased cardiovascular disease (CVD) risk. Currently, a systematic overview of the available evidence regarding maternal obesity and alterations in cardiac structure and function in human offspring is lacking. We systematically searched the electronic databases Embase, MEDLINE and NARCIS from inception to June 29, 2022 including human studies comparing cardiac structure and function from fetal life onwards in offspring of women with and without obesity. The review protocol was registered with PROSPERO International Prospective Register of Systematic Reviews (identifier: CRD42019125071). Risk of bias was assessed using a modified Newcastle-Ottawa scale. Results were expressed using standardized mean differences (SMD). The search yielded 1589 unique publications, of which thirteen articles were included. Compared to offspring of women without obesity, fetuses of women with obesity had lower left ventricular strain, indicative of reduced systolic function, that persisted in infancy (SMD -2.4, 95% confidence interval (CI) -4.4 standard deviation (SD) to -0.4 SD during fetal life and SMD -1.0, 95% CI -1.6 SD to -0.3 SD in infancy). Furthermore, infants born to women with obesity had a thicker interventricular septum (SMD 0.6 SD, 95% CI 0.0 to 1.2 SD) than children born to women without obesity. In conclusion, cardiac structure and function differs between fetuses and children of women with and without obesity. Some of these differences were present in fetal life, persisted in childhood and are consistent with increased CVD risk. Long-term follow-up research is warranted, as studies in offspring of older age are lacking.

Fetal echocardiographic parameters in pregnancies complicated by diabetes: a case control study

Background

At present, the prevalence of pregestational diabetes is 2.2% with an overall prevalence of hyperglycaemia in pregnancy of about 16.2%. Fetuses of diabetic mothers are at risk of functional cardiac abnormalities without structural cardiac anomalies especially in the third trimester. The main aim of this study was to assess the association of diabetes with different fetal echocardiographic parameters.

Methods

A case control study comprising a total of 120 pregnant women (60 cases and 60 controls). The cases group included fetuses of mothers known to have pre-gestational type 2 diabetes (DM group) while the control group included fetuses of euglycaemic healthy pregnant women. They were examined twice at 23–24 weeks' gestation (visit 1) and followed up at 27–28 weeks’ gestation (visit 2). The Modified Myocardial Performance Index (Mod MPI) was obtained in all fetuses. Also, M-mode echocardiography was used to measure the interventricular septum thickness at diastole in a transverse four chamber view.

Results

There was a significant increase in Iso-volumetric contraction time (ICT) (45.4 ms ± 8.9), Iso-volumetric relaxation time (IRT) (54.7 ms ± 11.22), Interventricular septal thickness (IVST) (4.08 mm ± 0.8), aortic acceleration time (AAT) (54.16 ms ± 12.77) and MPI (0.64 ± 0.09) in the diabetic group compared to the normal control group ICT (38.5 ms ± 9.59), IRT (46.13 ms ± 10.29), IVST (3.17 mm ± 0.6), AAT (49.73 ms ± 10.68) and MPI (0.5 ± 0.1) (all P values were < 0.001).

When comparing parameters assessed at both visits among diabetic patients, there was a significant increase in IVST in the second visit (4.74 ± 0.78 mm) compared to the first visit (4.08 ± 0.8 mm) (P value < 0.05).

The incidence of hypertrophic cardiomyopathy (HCM) was significantly higher in diabetic patients than in the control group. This is was observed in both first and second visit (33.4% and 56.7%) (P value < 0.001).

Conclusions

Fetuses of diabetic pregnant females show a significant increase in MPI, decrease in E\A ratio and HCM. These alterations in cardiac functions and structure were found to be continuous throughout the period of time between the two visits.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04969-5.