Ultrasonographic Application Study On The Width Of Fetal Cavum Septum Pellucidum

Part one: Analysis of ultrasonic measurement of the width of cavum septum pellucidum in normal fetuses ObjectiveThe purpose of this study is to make a large sample statistical analysis of the reference range of normal fetal cavum septum pellucidum(CSP)and its correlation with gestational age and biparietal diameter,so as to provide reference basis for clinic.Materials and methods1546 singletons who underwent Grade III prenatal ultrasound examination(systematic prenatal ultrasound examination)in the Ultrasound Department of the third affiliated Hospital of Zhengzhou University from January 2018 to December2019 and no abnormalities of central nervous system were retrospectively analyzed.Linear regression analysis was used to analyze the changing trend of CSP width with gestational weeks and biparietal diameter.Pearson correlation analysis was used to analyze the correlation between CSP width,biparietal diameter and pellucid septum ratio(BCR)and gestational weeks.The Kruskal-Wallis H test was used to compare the results among the groups,and the difference was statistically significant(P<0.05).Results1.The average reference range of fetal CSP width from 17 to 37 weeks was(4.64±1.32)mm;.The CSP width of each gestational week was not the same,and the difference was statistically significant(H=574.4,P < 0.001).2.There was a positive correlation between fetal CSP width and gestational age and biparietal diameter at 17～30 weeks of gestation(r = 0.63、0.65,P < 0.001),but there was no significant correlation with gestational weeks at 30～37 weeks(r =0.319,P < 0.001).3.The BCR was relatively constant at 19～30 weeks of gestation,with a reference range of(13.38±3.31).Conclusion1.The normal reference range of CSP width measured by ultrasound is different in different gestational weeks.2.The width of CSP was correlated with gestational age and biparietal diameter in the range of 17～30 weeks.3.The BCR was constant at 19～30 weeks of gestation.Part II Clinical significance of prenatal ultrasonographic diagnosis of abnormal width of fetal cavum septum pellucidum ObjectiveTo analyze the prenatal diagnosis and clinical prognosis of fetus with abnormal width of CSP diagnosed by ultrasound and to explore its clinical significance.Materials and methodsFetuses with abnormal CSP width diagnosed for the first time in the Department of Ultrasound of the third affiliated Hospital of Zhengzhou University from January 2018 to December 2019 were selected.270 fetus with isolated abnormal CSP width were divided into enlarged group(CSP width ≥ 10 mm,n=30),unshown group(CSP did not show,pellucid septum existed,n=33)and narrow group(CSP width ≤ 2 mm,n=207).51 fetuses in widened group were divided into isolated CSP broadening group(n = 30)and other malformations group(n = 21)according to whether they were complicated with other malformations.The general data of pregnant women,fetal prenatal diagnosis and postpartum nervous system development were statistically studied,and the clinical significance of prenatal diagnosis of fetal isolated CSP width abnormality and CSP broadening was analyzed.Results 1.General condition of three groups of isolated CSP width abnormalities: 7 cases lost follow-up,2 cases had chromosome abnormalities,1 case was selective intrauterine growth restriction,muscle strength was slightly weaker at 2 months old,and developed like children of the same age at 19 months of follow-up,and the other 20 cases were followed up to 4~29 months postpartum as children of the same age.In the unshown group,11/23 cases were found narrow CSP by fetal MRI examination;6 cases lost follow-up,27 cases(including 11 cases of narrow CSP found by MRI and 16 cases of unshown CSP)were followed up to 2~27 months after delivery with a good prognosis.In the narrow group,95/207 cases was found CSP width > 2mm by ultrasound in the later stage;33 cases lost follow-up,and 174 cases(including 95 cases with CSP width > 2mm,1 case with chromosome 2q13 microdeletion and other 78 cases with narrow CSP)developed like children of the same age at 4~29 months postpartum.2.The results of fetal head MRI examination: 71 cases received fetal head MRI examination.In 11 cases of widened group,1 case was showed partial agenesis of corpus callosum by MRI,but not by prenatal ultrasound,the other 10 cases were consistent with the results of ultrasound,23 cases of unshown group,of which 11 cases of MRI found narrow CSP,the other 12 cases were consistent with the results of ultrasound;and 37 cases of narrow group were consistent with the results of ultrasound.3.Results of fetal amniocentesis: 37 cases received prenatal amniocentesis.In the broadened group,1 case was 18-trisomy,1 case had absence of the splint of the corpus callosum,chromosome examination showed that there was a heterozygous mutation of FGFR3 gene c.749 C > G,and no abnormality was found in the other 4 cases;in the narrow group,1 case was arr [GRCh37] 2q13(110876776-11366256),and no abnormality was found in the other 18 cases.4.The results of isolated CSP width abnormality among the three groups: the gestational week detected by ultrasound in the widened group was later than that in the other two groups(P < 0.05).There was no significant difference in the high risk rate of maternal age among the three groups(P > 0.05).5.The results of Enlarged CSP group: in 21 cases with other malformations,12 cases were multiple malformations,all of them chose to induce labor,9 cases wereslightly abnormal,2 cases lost follow-up,and 7 cases were followed up for 2~27 months.Compared with the isolated CSP broadening group,the gestational age was detected earlier(P<0.05).Of the three groups,no significant difference was found in the width of CSP and pregnant women age(P > 0.05).Conclusion: 1.When the width of CSP is abnormal by ultrasound,fetal brain MRI and amniocentesis are helpful to guide clinical decision.2.Prenatal ultrasound showed that the outcome of the fetus with enlarged CSP depends on the severity of the associated malformation.3.After other abnormalities were excluded by further examination,the short-term prognosis of fetuses with abnormal width of isolated CSP was good.