First-Trimester Fetal Cardiac Function

Abstract

Objective. The purpose of this study was to establish normal values for fetal heart function in the first trimester. Methods. This was a prospective observational study with institutional ethics approval and written maternal consent. Thirty-two healthy pregnant women were recruited, and transabdominal fetal echocardiography was performed between 12 and 14 completed weeks' gestation. Myocardial function was assessed with the myocardial performance index to assess combined systolic and diastolic function, isovolumetric contraction time to assess systolic function, and isovolumetric relaxation time to assess diastolic function. Mitral and tricuspid inflows were also assessed by determining the ratio between passive and active ventricular filling. The ventricular outflows were also assessed by peak systolic velocities (PSVs) and time velocity integrals (TVIs). Results. The mean gestational age at the time of echocardiography was 13 weeks, and the mean crown-rump length was 79 mm. All fetuses had a normal nuchal translucency measurement (mean, 1.5 mm). The myocardial performance index was the same in the left and right sides of the heart, 0.5. The mean isovolumetric relaxation time and isovolumetric contraction time on the left side of the heart were 41 and 36 milliseconds, respectively. The mean passive/active ventricular filling ratio was 0.6 at both the mitral and tricuspid valves. The mean aortic PSV was 26 cm/s, and mean pulmonary artery PSV was 32 cm/s. The mean aortic outflow TVI was 3.6 cm, and the mean pulmonary outflow TVI was 4.1 cm. Conclusions. This study establishes normal values for cardiac function at 12 to 14 weeks' gestation. These values may assist in assessment of fetal health in early pregnancy. Key words: cardiac function; echocardiography; fetus; first trimester; myocardial performance index. dvances in ultrasound technology have led to improved visualization of the fetus in the first trimester. This has led to increased interest in examining the fetus for abnormalities, with early fetal echocardiography now offered in many units. A recent article on early fetal echocardiography in firsttrimester fetuses found that a satisfactory cardiac examination was possible in 95% of cases, with sensitivity of 70% and specificity of 98% for detection of cardiac defects. 1 Assessment of cardiac function with Doppler examination of the atrioventricular (AV) valves has been performed in early pregnancy. Those studies found that the proportion of the cardiac cycle occupied by both the isovolumetric relaxation time (IVRT) and isovolumetric contraction time (ICT) reduces during the first trimester. [2][3][4] The myocardial performance index (MPI) is a useful noninvasive Doppler-derived method of evaluating combined systolic and diastolic function, first described in

The (Pulsed-Wave) Doppler Fetal Myocardial Performance Index: Technical Challenges, Clinical Applications and Future Research

“…MPI has also been evaluated in first-trimester normal and complicated pregnancies [16,69,71,72,73,74,75,76,77,78,79], and compared with normal infants and children [11,54]. Reported Mod-MPI values for normal singleton fetuses range from 0.35 to 0.60 [9,11,54,55,62,67,68,79,80,81].…”

Tissue Doppler Is More Sensitive and Reproducible than Spectral Pulsed-Wave Doppler for Fetal Right Ventricle Myocardial Performance Index Determination in Normal and Diabetic Pregnancies

“…[2][3][4][5] Early detection of myocardial dysfunction may help guide management and may improve outcomes. Noninvasive detection of subtle abnormalities of cardiac function during development may also have implications for our understanding of disease and management.…”

Fetal nutritional origins of adult diseases: challenges for epidemiological research

“…Since these measurements need to be non-invasive, ultrasound or even magnetic resonance imaging should be considered. With these methods detailed studies of fetal cardiac, vascular, brain and kidney development can be performed [53][54][55][56][57][58]. We have recently shown circulatory adaptations in response to fetal growth retardation in a population-based cohort [59].…”

“…Detailed measurements, which are currently available in obstetric and fetal research, offer great opportunities for detailed measurements in epidemiological research. For example, with new ultrasound methods both structure and function of early and late placentation and fetal circulatory responses from first trimester onwards can be assessed [53][54][55][56][57][58].…”