Transvaginal three-dimensional ultrasound assessment of embryonic genital tubercle at 8-10+6 weeks of gestation.

OBJECTIVES: To assess embryonic genital tubercle using transvaginal three-dimensional (3D) ultrasound at 8-10+6 weeks of gestation. METHODS: One-hundred and two transvaginal 3D ultrasound scans were performed for first-trimester dating at 8-10+6 weeks of gestation. The genital tubercle angle (GTA) and genital tubercle length (GTL) were measured with a mid-sagittal view of the embryo using the 3D ultrasound multiplanar mode. Intra- and inter-observer agreements regarding GTA and GTL were also assessed with Bland-Altman plots and intra- and inter-correlation coefficients. RESULTS: There were no significant differences in GTA between male and female embryos at 8, 9, 10 weeks, or 8-10+6 weeks of gestation, respectively. There were also no significant differences in GTL between male and female embryos at 8, 9, 10 weeks, or 8-10+6 weeks of gestation, respectively. However, GTL increased linearly with advancing gestation (r=0.8276, p<0.00001). Mean GTL (SD) values at 8, 9, and 10 weeks were 0.833 mm (0.274), 1.623 mm (0.262), and 2.152 mm (0.420), respectively (p<0.001). Intra- and inter-reproducibilities of GTA and GTL were excellent. The intra- and inter-correlation coefficients of GTA and GTL were 0.964 and 0.995, and 0.996 and 0.9933, respectively. CONCLUSIONS: The genital tubercle could be identified using transvaginal 3D ultrasound at 8-10+6 weeks of gestation. However, sex differentiation could not be performed at this age. The genital tubercle linearly developed with advancing gestation during the mid-first trimester of pregnancy.

HDlive Flow Silhouette with spatiotemporal image correlation for assessment of fetal cardiac structures at 12 to 14 + 6 weeks of gestation.

OBJECTIVES: To assess fetal cardiac structures using HDlive Flow Silhouette with spatiotemporal image correlation (STIC) at 12 to 14 + 6 weeks of gestation, and verify the feasibility of obtaining five cardiac views in the late first and early second trimesters of pregnancy. The fetal cardiac shape and the aspect of the descending aorta were also evaluated. METHODS: Eighty normal fetuses at 12 to 14 + 6 weeks of gestation were studied using trans-abdominal HDlive Flow Silhouette with STIC to assess the feasibility of five fetal cardiac views (frontal, spatial three-vessel, panoramic, posterior, and right lateral views). Target structures in each cardiac view were evaluated. 'Good' was assigned when all structures were noted, 'Fair' when only one structure was missed, and 'Poor' when two and more structures could not be detected. Frequencies of an elongated heart and those of a tortuous descending aorta were counted. RESULTS: Forty-nine fetuses were effectively included in the analysis. Success rates of 'Good' and 'Fair' were significantly higher with spatial three-vessel (p<0.01) and panoramic views (p<0.05). Frequencies of "Elongated heart", "Elongated left ventricle", and "Spherical heart" were 12.2, 6.2, and 81.6%, respectively. Frequencies of "Tortuous descending aorta" and "Straight descending aorta" were 12.2 and 87.8%, respectively. CONCLUSIONS: The feasibility of obtaining fetal five cardiac views using HDlive Flow Silhouette with STIC is good, and this technique provides useful information for evaluating fetal cardiac structures in the late first and early second trimesters of pregnancy.

Evaluation of 24-segment sphericity index of fetal heart using FetalHQ.

OBJECTIVE: To evaluate the 24-segment sphericity index (SI) of the fetal heart using FetalHQ regarding the change with advancing gestation and reproducibility. METHODS: Eighty-one pregnant women at 18-21 + 6 and 28-31 + 6 weeks were studied using FetalHQ to calculate 24-segment SI of left and right ventricles. Intra- and inter-class correlation coefficients and intra- and inter-observer agreements of measurements for SI were assessed in each segment. RESULTS: With respect to intra-observer reproducibility, all SI values showed correlations between 0.596 and 0.774 for the left ventricle, and between 0.491 and 0.764 for the right ventricle, with good intra-observer agreements except for right ventricular segment 11-15. With respect to inter-observer reproducibility, all SI values showed correlations between 0.473 and 0.755 for the left ventricle, and between 0.48 and 0.767 for the right ventricular segment 1-18. However, right ventricular segment 19-24 showed no correlations. Good inter-observer agreements were noted in the right ventricle, whereas poor inter-observer agreements were evident in the left ventricle.There were significant differences in the mean SI values in the apical segment of the left ventricle between 18-21 + 6 and 28-31 + 6 weeks (p < .05), whereas there were no significant differences in the mean SI values in the right ventricle between both gestational ages. CONCLUSION: These results show that measurements of 24-segment SI of fetal heart had relatively low reliability of measurements performed by experienced sonographers. This may suggest that more training on proper placement of the 3 end-systolic and end-diastolic reference points during the initial analysis may be relevant.

Natural Course of Fetal Hyaloid Artery: SlowflowHD Longitudinal Study.

OBJECTIVE: To assess the natural course of the fetal hyaloid artery (FHA) using SlowflowHD during pregnancy. METHODS: One-hundred and eighteen normal fetuses were studied longitudinally using SlowflowHD to assess the natural course of FHA at 18-21 + 6, 28-31 + 6, and after 35 weeks of gestation. Blood flow of FHA with/without its branches (BF) was evaluated using SlowflowHD, and the band of FHA without blood flow (Band) was identified in each gestational period. The natural course of FHA was classified into six types: Type A, not detected (ND) in each gestational period; Type B, Band at 18-21 + 6 weeks; Type C, Band at 18-21 + 6 and 28-31 + 6 weeks; Type D, BF at 18-21 + 6 weeks; Type E, BF at 18-21 + 6 weeks and Band at 28-31 + 6 weeks; Type F, BF at 18-21 + 6 and 28-31 + 6 weeks. RESULTS: BF, Band, and ND were 83.5, 15.5, and 1.0% at 18-21 + 6 weeks, 8.8, 15.5, and 75.7% at 28-31 + 6 weeks, and 0, 0, and 100% after 35 weeks, respectively. Type A was 1.0%, Type B was 13.6%, Type C was 1.9%, Type D was 61.2%, Type E was 13.6%, and Type F was 8.7%. CONCLUSIONS: The presence of FHA blood flow before 30 weeks of gestation should be regarded as a physiologic phenomenon in normal fetuses.

A 24-segment fractional shortening of the fetal heart using FetalHQ.

OBJECTIVES: To evaluate 24-segment fractional shortening (FS) of the fetal heart using FetalHQ by speckle-tracking regarding reproducibility and the change with advancing gestation. METHODS: Eighty-one pregnant women at 18-21+6 and 28-31+6 weeks of gestation were studied using FetalHQ with the speckle-tracking technique to calculate 24-segment FS of left and right ventricles. Intra- and inter-class correlation coefficients and intra- and inter-observer agreements of measurements for FS were assessed in each segment. RESULTS: With respect to intra-observer reproducibility, all FS values showed correlations between 0.575 and 0.862 for the left ventricle, with good intra-observer agreements except for left ventricular segments 14-24. Right ventricular FS values showed correlations between 0.334 and 0.685, with good intra-observer agreements. With respect to inter-observer reproducibility, all FS values showed correlations between 0.491 and 0.801 for the left ventricle, with good intra-observer agreements except for left ventricular segments 16-22. Right ventricular FS values showed correlations between 0.375 and 0.575, with good inter-observer agreements. There were significant differences in the mean FS values in the basal segment (segments 1-5) of the left ventricle between 18 and 21+6 and 28-31+6 weeks of gestation (p<0.05), whereas there were significant differences in all mean FS values in the right ventricle between both gestational ages (p<0.05). CONCLUSIONS: These results suggest that the reproducibility of the 24-segment FS of the fetal heart using FetalHQ is fair. However, there may be significant differences in FS values with advancing gestational age, especially for the right ventricle.

Success rate of five fetal cardiac views using HDlive Flow with spatiotemporal image correlation at 18-21 and 28-31 weeks of gestation.

Objective To assess the success rates of five fetal cardiac views using HDlive Flow (Silhouette) with spatiotemporal image correlation (STIC) in the second and third trimesters of pregnancy, and to verify the feasibility of obtaining five cardiac views by volumes. Methods One hundred and eighteen normal fetuses at 18-21 and 28-31 weeks of gestation were studied using HDlive Flow (Silhouette) with STIC to assess the success rates of five fetal cardiac views (frontal, spatial three-vessel, panoramic, posterior, and right lateral views). Target structures in each cardiac view were evaluated. "Good" was assigned when all structures were noted, "Fair" when only one structure was missed, and "Poor" when two and more structures could not been detected. Results There were no significant differences in success rates of each cardiac view between 18-21 and 28-31 weeks of gestation. The rate of "Good" with a spatial three-vessel view was significantly higher than that with other cardiac views at 18-21 and 28-31 weeks, respectively (P < 0.05). Conclusion Five cardiac views using HDlive Flow (Silhouette) with STIC may become an adjunctive and useful tool in fetal cardiac examination.

Formulae Based on Biomathematics to Estimate the Standard Value of Fetal Growth of Japanese.

We devised biomathematics-based formulae to estimate the standard values of fetal growth of Japanese after 22 weeks' gestation. The growth rates of bi-parietal diameter (BPD), abdominal circumference (AC), femur length (FL), and estimated fetal body weight (EFBW) at the time of gestation were assumed to be proportional to the product of the value at the time and the rest value of an unknown maximum value, respectively. The EFBW was also assumed to follow a multiple logistic function of BPD, AC and FL to fit the standard values of Japanese fetuses published by the Japan Society of Ultrasonics in Medicine. The Mann-Whitney test was used for statistical analysis. The values as a function of gestational day, t, were as follows: BPD(t)=99.6/(1+exp (2.725-0.01837＊t)) (mm); AC(t)=39.7/(1+exp (2.454-0.01379＊t)) (cm); FL(t)=79.6/(1+exp (2.851-0.01710＊t)) (mm); EFBW(t)=8045.1/(1+exp (6.028-0.06582＊BPD(t)-0.1469＊AC(t)+ 0.07377＊FL(t))) (g). EFBW as a function of BPD, AC and FL was as follows: EFBW=8045.1/(1+exp (4.747+ 0.02584＊BPD+0.1010＊AC-0.1416＊FL)) (g). When the BPD, AC and FL were at -2 standard deviation (SD), -1SD, mean and + 2SD, the EFBW values calculated by the formula were statistically closer to the standard values than conventional formulas with p-values of 4.871×10-7, 4.228×10-7, 9.777×10-7 and 0.028, respectively. The formulae based on biomathematics might be useful to estimate the fetal growth standard values.