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Objective:To establish the normal reference range of the ratio of fetal umbilical venous flow rate to umbilical artery pulsatility index (VAI).Methods:A total of 816 normal fetuses underwent prenatal examination and delivery were randomly selected from October 2018 to December 2020 in Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region. Fetal weight was obtained by measuring fetal biparietal diameter, head circumference, abdominal circumference, and femoral length.Umbilical venous flow (Quv) was measured. Umbilical artery pulsatility index (UA-PI) was obtained in the free segment of amniotic fluid. Quv was standardized according to fetal size to calculate the umbilical venous flow rate (nQuv) and VAI. The association between Quv, nQuv, UA-PI, VAI and the fetal gestational week were analyzed using correlation analysis. VAI was presented as ± s, the upper limit of 95% reference value and the lower limit of 5% reference value were taken as the standards of VAI increase and decrease, respectively. Twenty-six fetuses whose VAI were lower than limit of 5% and 20 fetuse whose VAI were than limit of 95% were chosed as the case group. Results:①Fetal Quv was positively correlated with gestational week ( r=0.893, P<0.001), nQuv and UA-PI were negatively correlated with gestational week ( r=-0.552, -0.827; all P<0.001), and VAI had no significant correlation with gestational week ( r=0.000, P=0.758); ②The mean, standard deviation, lower 5% reference value, and upper 95% reference value of VAI were 195.81, 55.61, 105.95, and 293.33, respectively; ③In the cases with abnormal VAI, 26 fetuses with reduced VAI, of whom there were 16 cases of maternal hypertension, and 13 cases complicated by severe preeclampsia; 1 case with 40 turns of umbilical cord torsion, 3 cases of stillbirth, 16 cases of preterm delivery, 19 cases of low neonatal birth body weight, 4 cases of 1-min Apgar score ≤7, 6 cases of umbilical artery blood pH<7.2, and 1 case without abnormalities in fetus during pregnancy and follow-up newborn. Among the 20 fetuses with increased VAI, there were 10 cases of fetal severe thalassemia, 2 cases of thalassemia, 1 case of sacrococcygeal teratoma, 1 case of portal venous shunt, 3 cases of placental chorioangioma, and 3 cases without abnormalities in fetus during pregnancy and follow-up newborn. Conclusions:The measurement and calculation of fetal VAI is simple and easy to perform. As a comprehensive index, fetal VAI remains constant in mid and late pregnancy, facilitates the follow-up of abnormal fetuses, and has potential clinical application.
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Objective:To construct Z-score ranges for normal fetal middle cerebral artery peak systolic velocity(MCA-PSV).Methods:From May 2017 to October 2019, 865 normal singleton fetuses of 10th to 40th gestational weeks underwent prenatal ultrasound in the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region. Using fetal biometric parameters as independent variables, and measurement of MCA-PSV on standard section as dependent variables, the regression analyses of the mean(M) and the standard deviation(SD) for each parameter were calculated separately and then the best fitting equation was selected. A group of diseases which might cause the abnormal MCA-PSV were assessed using these standards.Results:①Strong correlations were found between MCA-PSV and fetal biometric parameters ( r=0.935-0.939, P<0.001). ②Quadratic or cubic regression equations were fitted to the models of the means of the MCA-PSV, whereas linear equations were fitted to the SDs. ③In these case groups, intrauterine growth restriction, severe preeclampsia, intrauterine infection and homozygous α-thalassemia-1 demonstrated Z-score>2 reflective of increased MCA-PSV with varying degrees, especially with the homozygous α-thalassemia-1 fetus being the most significant (17/20, 85%). Conclusions:The calculation of Z-score for MCA-PSV as a function of fetal biometric parameters is intuitive and simple, it can be used as an important indicator especially for homozygous α-thalassemia-1.
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Objective:To explore the values of Z-scores of fetal heart circumference (HC) and heart area (HA) in prediction of homozygous α-thalassemia.Methods:From February 2014 to March 2019, 233 fetuses of 15 to 23 gestation weeks with risk of homozygous α-thalassemia were examined by prenatal ultrasound in the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region. HC, HA and cardiothoracic ratio (CTR) were measured. HC and HA were converted into Z-scores, respectively. The ROC curves were established and analyzed based on HC Z-score, HA Z-score or CTR respectively to compare their predicting efficacies for fetal homozygous α-thalassemia. Finally, the sensitivity, specificity, positive predictive value and negative predictive value were obtained by the best cutoff values.Results:①Sixty-five fetuses were diagnosed as homozygous α-thalassemia and classified as α-thalassemia group. One hundred and sixty-eight fetuses were mild and normal and were classified as control group. ②HC Z-score, HA Z-score and CTR in the α-thalassemia group were significantly higher than those in the control group, and the differences between the two groups were statistically significant ( P<0.001). ③The area under ROC curve of HA Z-score was the largest compared with HC Z-score and CTR, and the prediction efficacy was the highest ( Z test=2.144 and 2.517 respectively, P<0.05). ④The best cutoff values were HC Z-score>1.67, HA Z-score>2.06 and CTR>0.53. Sensitivities of predicting homozygous α-thalassemia in 15 to 23 gestation weeks were 92.31%, 100% and 89.23%, respectively. Specificities were 94.05%, 95.83% and 93.45%, respectively. Positive predictive values were 84.43%, 89.00% and 84.05%, respectively. Negative predictive values were 96.91%, 100% and 95.57%, respectively. Conclusions:Fetal heart HC Z-score and HA Z-score are safe and effective novel ultrasonic indexes for predicting homozygous α-thalassemia. Especially compared with traditional CTR, HA Z-score has a significantly higher predicting efficacy, which can improve the detection rate of homozygous α-thalassemia and reduce the need for invasive examination.
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Objective To evaluate the efficacy of the ratio of the fetal cardiac diameter to biparietal diameter( CBR) as a predictor of homozygous α-thalassemia-1 . Methods Single mid-pregnancies ( 15-22weeks) at risk of homozygous α-thalassemia-1 were enrolled . A total of 251 singleton pregnancies were recruited ,in which 63 cases were homozygous α-thalassemia-1 fetuses and the rest were unaffected . The CBR and cardiothoracic ratio(CTR) were measured by two-dimensional ultrasound . Then the accuracy of these variables were analyzed and compared with each other by ROC curves . Results ①The CBR and CTR in affected fetuses were significantly higher than those in the unaffected( P ＜0 .01) . ②With CBR＞0 .43 and CTR ＞ 0 .52 as the best cut off values ,the sensitivity and specificity of predicting homozygous α-thalassemia-1 fetuses in 15-22 gestational weeks were 95 .74% , 92 .06% and 94 .15% , 85 .71% , respectively ;the area under ROC curve were compared with Z test and there was no significant difference between them ( Z ＝ 1 .500 , P ＝ 0 .1335) . ③ When CBR and CTR were combined ,the sensitivity and specificity of the prediction were significantly increased ( the sensitivity of series experiment : 99 .75% ,the specificity of parallel experiment : 98 .87% ) . Conclusions CBR is a novel , effective and noninvasive predictor of homozygous α-thalassemia-1 in mid-pregnancy whose prediction efficiency is the same as traditional CTR . The measurement of CBR is easier to standardize and is not affected by thoracic lesions such as pleural cavity ,pericardial effusion and skeletal dysplasia . If combined with CTR ,it may play an important role in improving the prenatal detection rate of homozygous α-thalassemia-1 fetuses .
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Regulation of blood lipid and anti-atherosclerosis is a hot topic in the study of poly unsaturated fatty acids in recent years. Many research showed that polyunsaturated fatty acids can inhibit atherosclerosis by reducing lipid, anti-inflammatory,anti-oxidative, inhibiting thrombosis and protecting vascular endothelial cells. Polyunsaturated fatty acids, due to their medicinal and edible homologues,have great potential drugs for regulating blood lipids and anti-atherosclerosis.