Preliminary Study On Parameters Of Auricle Morphology Of Fetus In Normal Early Pregnancy

Purpose Objective To use Two-dimensional ultrasound to study the parameters related to auricle morphology of fetus in normal early pregnancystudy parametersMethods The study collected binaural coronal sections were collected from 500 fetuses of whom the nuchal translucency was normal and ages ranged between 11?13+6 weeks.With this criterion,binocular orbits and both maxilla were presented at the same time to allow a measurement on the morphological parameter of fetal auricles.Each parameter was measured three times and the mean was taken as the final measurement value.Then,an analysis was performed on the relationship between the measured auricular morphological parameters and the crown-rump length(CRL)of fetuses during normal early pregnancy.To demonstrate the relationship,linearregression equations were subsequently established for these two objects.Results 342 fetal binaural coronal sections were obtained from 500 fetuses.The ears are in“eight”-shaped symmetry,of which the binaural long axis is at an acute angle with the cheek.The horizontal space between the inferior edges of two ears enlarged to 27.5mm from 16.5mm as the fetal CRL increased to 73 mm from 46 mm.The linear equation is formulated as: horizontal space between binaural inferior margins(mm)= 0.265×CRL+6.61(r=0.835,P<0.01).The binaural connection line is parallel with the connection line between double maxilla.The vertical distance between the midpoints of the binaural connection line and the bi-maxillary connection line lengthened from 3.5mm to 6.5mm.The linear equation is written as: vertical distance between the binaural connection line and the midpoint connection of bi-maxillary ossification(mm)= 0.097×CRL-0.63(r=0.884,P<0.01).The intersection angle of the binaural long axis extended line narrows down to 86.08° from 112.53°.Its linear equation is expressed as: intersection angle of binaural long axis extended line(°)=-0.950×CRL+154.46(r=-0.953,P<0.01).Conclusion The two ears of normal fetuses in the first trimester was patterned in “eight” character symmetry.Of them,the long axis is at acute angle with the cheek.The fetal CRL are positively correlated with both the horizontal space between binaural inferior edges and with the vertical distance between the binaural connection and the midpoint connection of bi-maxillary ossification.Moreover,the binaural connection is parallel with the bi-maxillary connection.A negative correlation is found between the intersection angle of binaural long axis extended lines and the fetal CRL.Thereupon,the morphological parameters of early-phased fetal auricles can provide a reference range for auricular deformity screening,and are also valuable to certain degree in clinical applications.and their change rule can provide some reference value for auricle malformation screening and has certain clinical significance.