Sonographic measurement of ear length among normal fetuses of pregnant Igbo women in port Harcourt, Nigeria

Felicitas Idigo,Angel-Mary Anakwue,Ebbi Robinson,Kingsley Ajibo,Uloma Nwogu

doi:10.4314/ahs.v21i1.43

Abstract

Fetal ear length measurement has been associated with some clinical values: sonographic marker for chromosomal aneuploidy and for biometric estimation of fetal gestational age. To establish a baseline reference value for fetal ear length and to assess relationship between fetal ear length and gestational age. Ear length measurements were obtained prospectively from fetuses in 551 normal singleton pregnancies of 15 to 41 weeks gestation. Normal cases were defined as normal sonographic findings during examination plus normal infant post-delivery. The relationship between gestational age (GA) in weeks and fetal ear length (FEL) in millimeters were analyzed by simple linear regression. Correlation of FEL measurements with GA, biparietal diameter (BPD), Head circumference (HC), Abdominal Circumference (AC), Femur Length (FL) and maternal age (MA) were also obtained. Linear relationships were found between FEL and GA (FEL=0.872GA-2.972). There was a high correlation between FEL and GA (r = 0.837; P = .001). Good linear relationship and strong positive correlation were demonstrated between FEL and BPD, AC, HC, and FL (p<0.05). The result of this study provides normal baseline reference value for FEL. The study also showed good linear relationship and good correlation between FEL and fetal biometric measurements.

Highlights

A number of researches have been carried out to correlate fetal ear length with fetal biometric measurements and gestational age
Studies have been done among different ethnic populations like the Turkish, Indians, Nepalese and Americans to establish a nomogram for fetal ear length, to help in the antenatal prediction of chromosomal abnormalities and estimation of gestational age
This is in conformity with previous findings among Turkish[3], Indians[4], Americans[20], Brazilians[23], Japanese[24], Americans[25, 26], and British[27] which found a linear relationship between fetal ear length with increase in gestational age

Summary

Introduction

A number of researches have been carried out to correlate fetal ear length with fetal biometric measurements and gestational age. Many of the studies identified the usefulness of the fetal ear length as a sonographic marker for fetal aneuploidies[1, 3, 4]. Between 11-13 weeks gestational age, Nuchal Translucency (NT) measurement above 3.5mm and nasal bone hypoplasia are sonographic markers for early prediction of fetal aneuploidy[12, 13, 14]. In 11-13 weeks, Nuchal Translucency (NT) scan and nasal bone are sonographic markers for early prediction of fetal aneuploidy[12]; other markers used in this period are ductus venoses spectrum, and tricuspid regurgitation. Fetal ear length measurement has been associated with some clinical values: sonographic marker for chromosomal aneuploidy and for biometric estimation of fetal gestational age. The relationship between gestational age (GA) in weeks and fetal ear length (FEL) in millimeters were analyzed by simple linear regression.

Objectives

Methods

Results

Conclusion