Evaluation of fetal heart geometry during pregnancy by three-dimensional ultrasound using the STIC rendering mode.

OBJECTIVE: To determine fetal heart geometry during pregnancy using three-dimensional (3D) ultrasound and the spatiotemporal image correlation (STIC) rendering mode. METHODS: This prospective, cross-sectional study evaluated 250 normal singleton pregnancies from 20 to 33 weeks and 6 days of gestation. STIC rendering was used to calculate the eight angles of the fetal heart: apex, base, mitral valve, tricuspid valve, left ventricle, right ventricle, left atrium, and right atrium angles. The concordance correlation coefficient (CCC) was used for intra- and inter-observer tests. RESULTS: The average ± SD maternal age was 31.7 ± 4.9 years, and the average gestational age was 26.3 ± 4.2 weeks. There was little variation in fetal heart angles using STIC rendering according to the gestational age, with determination coefficient (R2 ) values of 0.01 for the apex and mitral valve angles and <0.01 for the base, tricuspid valve, left ventricle, right ventricle, left atrium, and right atrium angles. Moderate/good intra- and inter-observer concordance was observed for the measurement of fetal heart angles using STIC rendering, and the obtained CCC varied from 0.74 to 0.93. CONCLUSION: The fetal heart geometry did not present significant variations during pregnancy using 3D ultrasound and the STIC rendering mode.

Reference Ranges of Fetal Cardiac Biometric Parameters Using Three-Dimensional Ultrasound with Spatiotemporal Image Correlation M Mode and Their Applicability in Congenital Heart Diseases.

To determine reference values for fetal heart biometric parameters using the spatiotemporal image correlation (STIC) M mode and their applicability in congenital heart diseases (CHDs). A cross-sectional prospective study was conducted with 300 singleton pregnancies between 20 and 33 + 6 weeks of gestation. Right ventricular wall thickness (RVWT), interventricular septum thickness (IVST), and left ventricular wall thickness (LVWT) were measured off-line using the STIC-M mode with the cursor perpendicular to the interventricular septum. Polynomial regressions adjusted with the coefficient of determination (R 2) were performed. The curves were applied to 14 fetuses with structural CHD. For the reproducibility calculations, the concordance correlation coefficient (CCC) was used. The mean RVWT, IVST, and LVWT were 0.34 ± 0.09 cm, 0.28 ± 0.09 cm, and 0.30 ± 0.07 cm, respectively. There was correlation between RVWT, IVST, and LVWT and gestational age (GA): RVWT = -0.002 + 0.013 × GA (R 2 = 0.33), IVST = -0.011 + 0.011 × GA (R 2 = 0.25), and LVWT = 0.056 + 0.009 × GA (R 2 = 0.26). RVWT, IVST, and LVWT were altered (<5th or >95th percentile) in 5/14, 5/14, and 7/14 of the fetuses with CHD, respectively. For RVWT, IVST, and LVWT, intra-observer (CCC = 0.86, 0.85, and 0.87, respectively) and inter-observer (CCC = 0.86, 0.86, and 0.86, respectively) reproducibility were good/moderate. The reference ranges determined for fetal heart biometric parameters using STIC-M had good intra- and inter-observer reproducibility and were applicable to fetuses with CHD.

Assessment of free fetal DNA concentration in maternal plasma during the first trimester of pregnancy: comparative study between EDTA and PPT tubes - pilot study.

OBJECTIVE: To compare ethylenediamine tetraacetic acid (EDTA) tubes and plasma preparation tubes (PPT) for evaluating maternal plasma during the first trimester of pregnancy. METHODS: A cross-sectional study was conducted on 24 male fetuses in women between 6 and 14 weeks of pregnancy. Blood samples (10 mL) were collected and stored in EDTA and PPT tubes. Subsequently, the samples were centrifuged and sent for free fetal DNA extraction by means of the polymerase chain reaction (PCR) technique. The reactions were performed in a real time PCR machine for detecting the amplification products. The genome region chosen for performing the PCR reactions was a target specific for the Y chromosome, in which the DYS-14 marker was amplified only when the DNA was of male sex. The free fetal DNA concentration was given by the threshold cycle (TC). To compare the tubes, the paired Student t-test was used. RESULTS: The mean gestational age was 11.08 ± 2.30 weeks (range: 6-14). The mean TC for PPT was 30.08 ± 1.05 (range: 27.08-32.61) and for EDTA, 30.23 ± 0.96 (range: 28.01-32.09), but without statistical significance (p=0.357). CONCLUSION: We did not observe any statistically significant difference in free fetal DNA concentration between the EDTA and PPT tubes.

Prenatal diagnosis of a fetus with ring chromosomal 15 by two- and three-dimensional ultrasonography.

We report on a prenatal diagnosis of ring chromosome 15 in a fetus with left congenital diaphragmatic hernia (CDH) and severe intrauterine growth restriction (IUGR). A 31-year-old woman, gravida 2 para 1, was referred because of increased nuchal translucency at gestational age of 13 weeks. Comprehensive fetal ultrasound examination was performed at 19 weeks revealing an early onset IUGR, left CDH with liver herniation, and hypoplastic nasal bone. Three-dimensional ultrasound (rendering mode) showed low set ears and depressed nasal bridge. Amniocentesis was performed with a result of a 46,XX,r(15) fetus after a cytogenetic study. A 1,430 g infant (less than third percentile) was born at 36 weeks. The infant presented with respiratory failure and died at 2 h of life. Postnatal karyotype from the umbilical cord confirmed the diagnosis of 15-ring chromosome. We described the main prenatal 2D- and 3D-ultrasound findings associated with ring chromosome 15. The interest in reporting the present case is that CDH can be associated with the diagnosis of 15-ring chromosome because the critical location of the normal diaphragm development is at chromosome 15q26.1-q26.2.

New anatomical landmarks to study the relationship between fetal lung area and thoracic circumference by three-dimensional ultrasonography.

OBJECTIVE: To evaluate the relation between total lung area (TLA) and thoracic circumference (TC) ratio by three-dimensional (3D) ultrasonography applying new anatomical landmarks as the fetal aorta and inferior angle of the scapula. METHODS: A longitudinal prospective study was conducted with 56 uncomplicated pregnancies between 24 and 32 weeks of gestation. Polynomial regressions were used to evaluate the correlation between TC and gestational age (GA) as well as TC and estimated fetal weight (EFW). A simple linear regression was used to evaluate the correlation between TLA and Total thoracic area (TTA) and GA. The intraclass correlation coefficient (ICC) was used to assess the intra and interobserver variability. RESULTS: 127 examinations were performed. TC values ranged from 150 to 174 mm (mean 166 mm) at 24 weeks and 215-248 mm (mean 231 mm) at 32 weeks. The TLA/TC ratio ranged from a mean of 0.64 at 24 weeks (range 0.56-0.70) to 0.90 at 32 weeks gestation (range 0.79-1.01). The intraobserver variability using the ICC was of 0.919 for TC; 0.916 for TTA; 0.860 for right lung area (RLA) and 0.910 for left lung area (LLA). Interobserver reproducibility was with an ICC of 0.970 for TC; 0.984 for RLA and 0.910 for LLA. CONCLUSIONS: Measurement of fetal TC and the relationship between TLA and TC by 3D-ultrasonography applying new anatomical landmarks shows good reproducibility and allows a new assessment of thoracic and lung growth.

Reference range of fetal renal volume by three-dimensional ultrasonography using the VOCAL method.

OBJECTIVE: To establish reference values for fetal renal volume by three-dimensional sonography using the VOCAL (Virtual Organ Computer-Aided Analysis) method. METHODS: This prospective longitudinal study involved 57 healthy pregnant women who were examined between 24 and 34 weeks of pregnancy. Each fetal kidney was evaluated separately using the VOCAL method with a 30 degree rotation angle. For each gestational age, the following measures were obtained for the right and left kidneys: mean, standard deviation, minimum and maximum values, and the 5th, 10th, 25th, 50th, 75th and 90th percentiles. Polynomial regression models were constructed to assess the relationship between renal volume and gestational age, adjusted by the determination coefficient (R(2)). The Wilcoxon test was used to evaluate the concordance between the right and left renal volumes. Bland-Altman graphs were used to assess intra- and inter-observer variability. RESULTS: The right renal volume increased from 4.5 +/- 1.3 cm(3) at 24 weeks to 12.1 +/- 1.5 cm(3) at 34 weeks. The left renal volume increased from 4.6 +/- 0.8 cm(3) at 24 weeks to 11.9 +/- 1.1 cm(3) at 34 weeks. There was a strong correlation between both the right and left renal volumes and gestational age (R(2) = 0.975 and 0.970, respectively). There were no significant differences between the right and left renal volumes. The mean difference between repeated measures by the same examiner was -0.07 cm(3) (-0.88 to 0.75) for the right kidney and -0.21 cm(3) (-0.95 to 0.75) for the left kidney. The mean difference between repeated measures obtained by two different examiners was -0.07 cm(3) (-1.25 to 1.12) for the right kidney and 0 cm(3) (-1.53 to 1.53) for the left kidney. CONCLUSION: Reference values were generated for fetal renal volume assessed by three-dimensional ultrasonography using the VOCAL method.

Fetal lung volume: comparison by 2D- and 3D-sonography in normal fetuses.

PURPOSE: To compare two-dimensional ultrasonography (2D US) and three-dimensional ultrasonography (3D US) in the assessment of normal fetal lung volume. METHODS: A cross-sectional study was performed involving 50 normal pregnancies at 24-32 weeks' gestation. The following equations were used for lung volume calculation by 2D US: Eq(2D1) = 4.24 + {1.53 x [(area of base of both lungs) x 1/3 (height of right lung)]} and Eq(2D2) = [anteroposterior diameter (X) x transverse diameter (Y) x cranial-caudal diameter (Z) of the right lung x 0.152 + (X') x (Y') x (Z') of the left lung x 0.167]. For 3D US, the virtual organ computer-aided analysis (VOCAL) method was used with a 30 degrees rotation angle and the total lung volume (V3D) was obtained by summing the volumes of each lung. Regression models (R (2)) were devised to assess lung volume evolution over the course of the pregnancy. Pearson's correlation coefficient (r) was used to assess correlation among the techniques, while Friedman's test was used for means comparisons. RESULTS: Strong correlation was observed among the three techniques [V3D vs. Eq(2D2) r = 0.856; V3D vs. Eq(2D1) r = 0.838 and Eq(2D2) vs. Eq(2D1) r = 0.964; all with P < 0.001]. Mean lung volumes were 37.05 +/- 9.67, 29.79 +/- 8.79 and 12.67 +/- 4.12 ml for V3D, Eq(2D1) and Eq(2D2), respectively (P < 0.001). CONCLUSIONS: Strong correlation and significant difference was observed among the three techniques of fetal lung volume assessment in normal fetuses.