Antenatal Ultrasound Fetal Pinna Measurement and Evolving Nomogram in South Indian Population in Normal Pregnancies

Abstract

Introduction: The abnormality of pinna length and morphology can indicate chromosomal anomaly and can be a marker for chromosomal aneuploidy. There are many studies about sonographic pinna length measurements correlating this with gestational age and fetal biometric measurements. Studies have been done in different population about the ultrasound pinna measurement with deduction of nomogram. To our knowledge this study has not been done on the South Indian population. Aim: To evolve nomogram for fetal pinna length measurement for South Indian population and to correlate this with gestational age and fetal biometry. Materials and Methods: Pinna length measurements (from the tip of the helix to the tip of the lobe) are measured prospectively in normal singleton pregnancies between 16- 28 weeks. Normal pregnancy is normal sonographic study and/or normal infant examination after birth. The ear length is measured in either oblique sagittal or coronal plane in millimeters and this is correlated with the gestational age and fetal biometry. Results: There is a linear relationship between the pinna length and the various fetal biometric parameters and the gestational age of the fetus. Conclusion: Study deduces the nomogram of the fetal pinna length. A linear relationship between the pinna length and the gestational age was established and there is no significant difference of pinna length as compared to the studies done on the other populations.

Keywords

• chromosomal abnormality
• fetal morphology
• ultrasound marker