Specificity of hypocoiled umbilical cord in prediction of fetal trisomy 21 in the second trimester.

Objective: To assess the sonographic morphology of umbilical cord coiling in chromosomally normal fetuses and estimate the specificity of hypocoiled appearance as a marker for fetal trisomy 21 in the second trimester. Methods: 555 singleton pregnancies undergoing amniocentesis for fetal karyotype were scanned at 17-22 weeks’ gestation. The umbilical cord was evaluated in a longitudinal section using 2D with color Doppler sonography. The cross-sectional data of umbilical coiling index (UCI), defined as the reciprocal of the distance between umbilical coils, were analyzed to establish the normal range according to the gestational age. A UCI less than the 5th percentile was the cut-off value for hypocolied umbilical cord. The specificity of hypocolied umbilical cord to predict fetal trisomy 21 was calculated. Results: As a result of amniocentesis, there were 527 chromosomally normal fetuses and 9 trisomy 21 fetuses. There was no significant difference in maternal characteristics between these two groups. In trisomy 21 fetuses, there was a higher proportion of fetal anomaly indicating for fetal karyotype (22.2% VS 0.6%, p = 0.003). The regression equation of UCI (cm-1, y) on gestational age (weeks, x) was y = 1.205 - 0.033x. The hypocoiled umbilical cord was characterized in 2/9 (22.2%) fetuses with trisomy 21 and in 22/527 (4.2%) chromosomally normal fetuses (p = 0.01), with specificity of 95.83%. Conclusion: The coiling pattern of umbilical cord visualized by sonography has a potential value in second-trimester screening for fetal trisomy 21. Nevertheless, further studies of this model in a larger cohort would provide more information in sensitivity and predictive values.

Reference centile chart for transverse cerebellar diameter (TCD) in Thai fetuses throughout gestation.

Objective: To create a reference centile chart for transverse cerebellar diameter in Thai fetuses throughout gestation. Methods: A total of 780 pregnant women between 13-40 weeks gestation, who attended at the antenatal clinic at Siriraj Hospital, Mahidol University, Bangkok, were recruited. Each fetus was measured only once for the purpose of this study. The mean and fitted centiles were estimated at each week of gestation using linear regression modeling. Results: A total of 752 fetuses were measured for fetal transverse cerebellar diameter. Linear regression models were fitted to estimate the meant 95% confidence interval for transverse cerebellar diameter at each gestational age. The centile chart of this parameter was also presented. Conclusion: Reference centile chart for fetal transverse cerebellar diameter of Thai fetuses was created.

Reference centile chart for fetal liver length of Thai fetuses.

OBJECTIVE: To create a reference centile chart for fetal liver length of Thai fetuses. DESIGN: Prospective, cross-sectional study. SETTING: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University. MATERIAL AND METHOD: A total of 752 pregnant women, who attended the antenatal clinic at Siriraj Hospital, Mahidol University, Bangkok, were recruited between 13-40 weeks of gestation. Each fetus was measured only once for the purpose of this study. Using real-time ultrasound with a 3.5 MHz convex transducer; the authors measured fetal liver length. The mean and standard deviation (SD) were estimated at each week of gestation using linear regression modeling. RESULTS: A total of 750 fetuses were measured for fetal liver length. Linear regression models were fitted to estimate the mean and 95% confidence interval for liver length at each gestation age. The centile chart of liver length was also presented CONCLUSION: A reference centile chart for fetal liver length of Thai fetuses has been created.

Sonographic morphological pattern in the pre-operative prediction of ovarian masses.

The study was undertaken to evaluate the accuracy of sonographic morphological pattern in the detection of ovarian malignancy. A total of 123 patients with a suspicion of ovarian pathology, who were scheduled for elective surgery at the Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University were included in the study. All patients underwent sonographic examination prior to surgery by the same physician. The sonographic morphological pattern of each patient was compared to the histological diagnosis of the ovarian tumors. Of the 120 patients with an ovarian lesion, the sonographic morphological pattern of 10 had a sensitivity of 88.6 per cent and a specificity of 89.4 per cent in detection of malignant ovarian tumors. The positive predictive value, negative predictive value, and the accuracy rate were 77.5, 95.0, and 89.2 per cent, respectively. In the present study, a score of 9 would be the best discriminator between benign and malignant ovarian masses, giving a sensitivity of 97.1 per cent and specificity of 82.4 per cent. As stand alone, the present results confirm that ultrasonography is still a useful diagnostic tool in the differentiation of benign from malignant ovarian masses.