Objective:To explore the feasibility of ultrasound screening and diagnosis of fetal cleft palate in early pregnancy, analyze and summarize the imaging technology and image characteristics of two-dimensional and three-dimensional ultrasound in normal fetus and cleft palate fetus.Methods:A total of 10 519 pregnant women participated in the early pregnancy were included from January 2016 to June 2020 in Shenzhen Hospital, University of Chinese Academy of Sciences. The palatal line on the standard section of fetal nuchal translucency (NT) measurement was used as a screening marker for routine observation. For fetuses with abnormal palatine line, posterior nasal triangle of coronal plane and axial plane of maxillary alveolar arch of two-dimensional ultrasound were added as the diagnostic sections, and three-dimensional volume data of fetal face were collected, and three dimensional multimodal imaging technology was used to analyze the volume data off-line to determine or exclude fetal severe cleft palate. All fetuses were followed up during the second trimester for deformity scanning and post natal (or induced labor) assessment.Results:Of the 10 519 fetuses, the standard NT plane was obtained and the palatal line was observed in 10 204 cases(97.01%), with normal palatal line in 10 169 cases.In 35 suspected cases, 13 cases were confirmed cleft lip and palate by two and three dimensions ultrasound, and were confirmed by induced labor. There were 7 cases in unilateral side, 3 cases in bilateral, 2 cases in median cleft lip and palate, 1 cases in irregular cleft lip and palate, and no false positive results were reported. Twenty-two suspicious cases were excluded by increasing the two-dimensional sectional and three-dimensional volumetric off-line analysis, and screening after the second trimester and after birth. There was 1 case of missed diagnosis of simple cleft palate.Conclusions:Palatal line is a good screening marker for fetal cleft palate in early pregnancy. For fetuses with abnormal palatine line, the adding of posterior nasal triangle and the axial plane of maxillary alveolar arch, and combining three-dimensional volume data for off-line analysis can determine or exclude severe cleft palate. This study is of great significance for early screening and diagnosis of severe fetal cleft palate, prenatal genetic counseling and prevention birth defect.

To identify the related substances of fusidic acid by LC-MS,separation was performed on an Agilent Extend-C18column(150 mm ×4. 6 mm,3. 5 μm)by linear gradient elution with a mobile phase consisting of methanol,acetonitrile and formic acid. Electrospray positive ionization high resolution TOF/MS was used for the determination of the accurate mass and elemental composition of parent ions of the related substances;triple qua-drupole tandem mass was employed for the mass spectra determination of the product. The structures of the related substances were then figured out through the elucidation of the fragment ions. Fusidic acid and its related sub-stances were adequately separated under the established HPLC conditions. Nineteen major related substances of fusidic acid were detected and speculated by hyphenated techniques. Eleven of them were recorded in European Pharmacopoeia,while the others have not been previously reported. The established LC-MS method is effective for the separation and identification of the related substances of fusidic acid and the results are useful for its storage conditions and quality assurance.