Development of the Z-score for the measurement of myocardial thickness by two-dimensional echocardiography in normal fetuses

Reference Ranges and Z-Score Equations for 19 Fetal Cardiac Biometry Structures From 18 to 34 Weeks' Gestation

OBJECTIVE

To determine equations for calculating the Z-scores of fetal cardiac structures between 18+0 and 34+6 weeks of gestation, create percentile reference tables and curves for the structures, and assess the intra- and inter-observer reproducibility of the measurements.

METHODS

A cross-sectional study was conducted involving 340 normal fetuses from singleton pregnancies between 18 and 34 weeks of gestational age (GA). Nineteen cardiac structures were evaluated: diameters of the mitral, tricuspid, aortic, and pulmonary valve annuli; length, diameter, and area of the left and right ventricles; cardiac area and circumference; and diameters of the ascending aorta, aortic isthmus, main pulmonary artery, right pulmonary artery, left pulmonary artery, and ductus arteriosus. Regression analysis was performed to determine the equations for the mean and standard deviation of all structures using GA, biparietal diameter (BPD), and femur length (FL) as independent variables.

RESULTS

All equations had high coefficients of determination (R2). The best performance was achieved using the GA (R2 .819-.944), followed by FL (R2 .813-.937) and BPD (R2 .792-.934). The structure that demonstrated the highest R2 was the cardiac circumference and the smallest was the ductus arteriosus. Reference tables of percentiles 1, 5, 10, 50, 90, 95, and 99, and reference curves of Z-scores were created for all 19 cardiac structures, depending on the GA. All measurements demonstrated good and excellent reproducibility with an inter-observer intraclass correlation coefficient (ICC) of 0.774-0.972 and intra-observer ICC of 0.938-0.993.

CONCLUSIONS

Equations were produced to calculate Z-scores as well as percentile tables and curves for 19 fetal heart structures. All the measurements demonstrated good reproducibility.

Analysis of automatic fetal intracranial volume (ICV) measurement based on the optimized ultrasound Smart ICV method at 16-34 weeks of gestation

BACKGROUND

Fetal intracranial volume (ICV) can help evaluate the development of the prenatal central nervous system (CNS) from the three-dimensional (3D) attributes of the cranial structure. Accurate and rapid segmentation and calculation of the ICV are clinically significant. Virtual organ computer-aided analysis (VOCAL) is a commonly used method for measuring fetal ICV. However, its operation is highly complex and time-consuming. This study aimed to optimize the fetal Smart ICV method at 16-19 gestational weeks, verify the consistency of automatic and manual measurement of ICV, and assess an automatic and efficient method for evaluating fetal ICV growth in the second and third trimester of pregnancy.

METHODS

The ultrasound data of 950 healthy fetuses at 16-34 weeks of gestation were collected. First, the Smart ICV algorithm was optimized at 16-19 weeks. Second, the optimized Smart ICV was compared with the manual VOCAL method. Finally, growth curve and Z-score estimations for fetuses were established for growth assessment via optimized Smart ICV.

RESULTS

Compared with the nonoptimized version, the optimized Smart ICV yielded a lower Hausdorff distance (1.15±0.25 vs. 1.31±0.93 mm, P<0.05). Both intra- and inter-observer agreements were at a high level for ICV measurement based optimized Smart ICV [intra-observer intraclass correlation coefficient (ICC) =0.998, 95% confidence interval (CI): 0.996-0.999; inter-observer ICC =0.991, 95% CI: 0.988-0.996] and the 18 plane-VOCAL (intra-observer ICC =0.997, 95% CI: 0.995-0.998; inter-observer ICC =0.981, 95% CI: 0.979-0.991). Additionally, Bland-Altman analysis showed that the ICV data for the above two models had good agreement. Nevertheless, compared with the 18 plane-VOCAL, the optimized Smart ICV consumed less time (3.7±0.7 vs. 153.1±29.5 s, P<0.05). The best fitting model of gestational week for the Smart ICV was a cubic function, expressed as follows: y = -44.2445 + 0.1427x 2 + 0.0052x 3, where y is ICV and x is the gestational week. In addition, fetal ICV showed an accelerated growth trend in the second trimester.

CONCLUSIONS

The optimized Smart ICV showed excellent accuracy and efficiency in ICV measurements at 16-34 gestational weeks. Our results may help to establish a best-fit growth curve for ICV. Our findings suggest that the optimized Smart ICV method has the potential to be a reliable tool for fetal growth assessment during the second and third trimesters.

Measuring the Area of the Interventricular Septum in the 4-Chamber View: A New Technique to Evaluate the Fetus at Risk for Septal Hypertrophy

OBJECTIVES

One of the problems for the clinician who desires to measure the interventricular septum (IVS) in a high-risk fetus is to know where to make the measurement. The purpose of this study was to use speckle-tracking analysis to measure the IVS area, 24-segment widths, and length at end-diastole (ED) and end-systole (ES) in normal fetuses.

METHODS

From the 4-chamber view, speckle-tracking analysis was performed at ED and ES on the IVS in 200 normal fetuses. The following were computed and regressed against gestational age (GA) and fetal biometric (FB) measurements: area, length, and the 24-segment transverse widths from the apex to the crux. The 24-segment width/length ratio was also measured. The speckle-tracking measurements of the ED area and length were compared using a point-to-point measurement tool available on all ultrasound machines.

RESULTS

The ED and ES areas, lengths, and 24-segment widths increased with GA and FB. The ED and ES areas were virtually identical. The 24-segment width/length ratio decreased from the apex to the crux of the septum. There was no significant difference in the measurement of the ED area and the length between speckle-tracking and the point-to-point measurements.

CONCLUSIONS

Measurement of the area and length of the IVS are simple to obtain and provide a new diagnostic tool to evaluate the fetus at risk for IVS hypertrophy which may be observed in fetuses of mothers with pregestational and gestational diabetes.

Early Assessment of Cardiac Function by Echocardiography in Patients with Gestational Diabetes Mellitus

Objective

To offer a baseline for clinical diagnosis, echocardiography was performed to evaluate the disparities in heart function comparing pregnant women with diabetes mellitus (GDM) and ordinary pregnant women.

Methods

A prospective case-control study is being conducted on pregnant women with or without gestational diabetes. The sample size for both the intervention and control groups is the same: no diabetes diagnosis or previous forms, a single pregnancy, and no issues (such as preeclampsia or fetal growth restriction). The females were all subjected to routine echocardiograms to examine the morphology and function of their left and right hearts.

Results

In the research, 51 women with GDM and 50 healthy controls volunteered. Women with GDM had a significantly higher heartrate (82 ± 9 vs. 74 ± 8), left ventricular (LV) relative wall thickness (0.39 ± 0.06 vs. 0.31 ± 0.07; P < 0.001), LV early diastolic transmitral valve velocity (E) (0.79 ± 0.14 vs. 0.72 ± 0.13 m/s; P = 0.031), and LV late diastolic implementing regulations valve velocity (0.6). Speckle-tracking analysis showed significant decrease in LV right ventricular (RV). A study indicated a reduced pulmonary acceleration time (59 ± 9 vs. 68 ± 12 ms; P = 0.001), RV E/A ratio (1.21 ± 0.19 vs. 1.31 ± 0.31; P = 0.022), and a greater RV myocardial systolic annular velocity (0.17 ± 0.03 vs. 0.12 ± 0.03; P = 0.023).

Conclusions

Our results revealed that the heart function of diabetic pregnant women differed considerably from that of the control group, such as LV-RWT, LV diastolic transmitral valve speed, and LV late diastolic transmitral valve speed. Given these results, further research into the postpartum cardiovascular healing of pregnant women with gestational diabetes mellitus is required.

Fetal Interventricular Septum Volume Evaluated by Three-Dimensional Ultrasound Using Spatiotemporal Image Correlation and Virtual Organ Computer-Aided Analysis in Fetuses From Pre-Gestational Diabetes Mellitus Pregnant Women

BACKGROUND

To assess the interventricular septum (IVS) volume of fetuses from pre-gestational diabetes mellitus (DM) pregnant women by 3-dimensional ultrasound using spatiotemporal image correlation (STIC) and virtual organ computer-aided analysis (VOCAL) methods.

METHODS

This was a prospective cross-sectional study of 45 fetuses from pre-gestational DM and 45 fetuses from healthy pregnant women (controls). Only singleton pregnancies between 20 and 34 + 6 weeks of gestation were included. The fetal IVS volumes were obtained off-line using STIC and VOCAL methods. To analyze differences among variables, the Student’s t-test and Mann-Whitney U test were used. The correlation among continuous variables was determine using Spearman’s correlation test (r).

RESULTS

The median of fetal IVS volume was significantly higher in pre-gestational DM than in healthy pregnant women (0.3 cm³ vs. 0.2 cm³, p = 0.032). A strong positive correlation was observed between fetal IVS volume and gestational age at the time of ultrasound examination (r = 0.75, R² = 0.48, p < 0.0001) and between fetal IVS volume and estimated fetal weight (r = 0.63, R² = 0.37, p < 0.0001). No significant correlation was noted between fetal IVS volume and glycated hemoglobin levels (r = −0.16, R² = 0.01, p = 0.540) in the pre-gestational DM pregnant women.

CONCLUSIONS

Significant differences were observed in fetal IVS volumes between pre-gestational and healthy mothers, with higher values in the fetuses of pre-gestational DM pregnant women.