Audiological functions in pregnancy

Abstract

Introduction: During pregnancy virtually every organ system undergoes anatomical and physiological changes that can alter appreciably the criteria for diagnosis and treatment of diseases. Hormonal fluctuations alter the composition of endolymph and perilymph, and ion transport process. Hence, audiological functions in pregnancy need evaluation. Materials and methods: After approval of Institutional Ethics Committee, 100 pregnant women were recruited in the 1st trimester. Tuning tests were done using 128, 256, 512, and 1024 Hz tuning forks. Pure tone audiometry was done and hearing thresholds measured for 125, 250, 500, 1000, 2000, and 4000 Hz. Finally, impedance audiometry was done in all the women in each trimester. Results: There was no air–bone gap. There was gradual reduction in hearing acuity at low frequencies (125, 250, 500, and 1000 Hz) from 1st to 3rd trimester of pregnancy. The hearing thresholds got stabilized in the 3rd trimester and returned to normal in postpartum period. For 2000 Hz and higher frequencies, there was no significant difference in relation to pregnant subjects. Number of pregnancies did not affect the audiological functions. Conclusion: Low-frequency hearing loss during pregnancy appears to be transient in nature with complete resolution in the postpartum period in most cases. For better understanding of these changes, obstetricians and otolaryngologists can team-up and avoid use of drugs for their symptoms during pregnancy.