Tehran University of Medical Sciences Auditory and Vestibular Research 2423-480X 24 4 2015 11 25 Auditory brainstem responses during menstrual cycle and pregnancy 217 223 EN Sahar Avizheh Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran Mehdi Akbari Department of Audiology, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran Jamileh Fatahi Department of Audiology, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran Akram Pourbakht Department of Audiology, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran Shohreh Jalaie Biostatistics, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran Kianoush Sheikholeslami Department of Surgery, Section of Neuro-Oncology, Robert Wood Johnson University Hospital, Cancer Institute of New Jersey, Rutgers University, New Brunswick, New Jersey, USA 2015 10 07 2015 10 07 Background and Aim: The sexual hormones alter during menstrual cycle and pregnancy. Despite the physiological benefits of these changes, their adverse effects on hearing system such as hearing loss and vertigo have been reported. Therefore, in this study, the auditory brainstem responses (ABR) were investigated during physiological hormonal variations in the menstrual cycle as well as pregnancy. Methods: In this comparative-cross sectional research, the ABR was assessed in 25 women, including 17 pregnant and 8 non-pregnant women. The assessment was conducted at 24th week of pregnancy and in two stages of the menstrual cycle, on the 1st-3rd day and once again during the 12th-15th day in non-pregnant women (control group). Click stimuli ABR was recorded and compared between aforemen­tioned groups. Results: According to our results, ABR wave V absolute latency, III-V and I-V interpeak latencies were significantly longer during the 12th-15th day of menstrual cycle compared to 1st-3rd day results (p<0.05). These significant increases were observed between pregnant women and control groups (p<0.05). Conclusion: The research revealed the influ­ence of hormonal changes during menstrual cycle and pregnancy on brainstem and auditory pathways. We concluded that the brainstem auditory pathways processing decelerates with the increase of estrogen and progesterone hormones. https://avr.tums.ac.ir/index.php/avr/article/view/31 https://avr.tums.ac.ir/index.php/avr/article/download/31/30