Sudden hearing loss and pregnancy: a review

Risk Factors, Complications, and Treatment Modalities for Sudden Sensorineural Hearing Loss in Pregnant Women: A Systematic Review and Meta-analysis

BACKGROUND

Sudden sensorineural hearing loss (SSNHL) during pregnancy is a rare condition and has not been much studied. The study aimed to perform a systematic review and meta-analysis of the risk factors, complications, and treatment modalities for SSNHL in pregnant women.

MATERIALS AND METHODS

PubMed, Web of Science, Scopus, ProQuest, and Google Scholar were used for the literature search. The Cochrane technique for assessing risk of bias was used for the article quality appraisal, and RevMan 5.4 was used for conducting the meta-analysis. Standard mean difference (SMD) and odds ratios with a 95% confidence interval (95% CI) were utilized. Heterogeneity and publication bias were assessed using the I-square (I2) test statistic and the Egger's test, respectively.

RESULTS AND DISCUSSION

The seven primary studies employed prospective and retrospective study designs. The meta-analysis showed that there were fewer risk variables for SSNHL in the experimental group compared with those in the control group (SMD = -0.45 to 3.24, 95% CI = -3.063.63 to 2.16-2.85), indicating that the analysis revealed an insignificant difference. However, the treated patients presented hearing improvement, suggesting a significant analysis (SMD = -0.6710.20, 95% CI = -1.2713.51 to -0.066.88). Furthermore, after therapy, substantial differences were observed in SMD between the two groups (SMD = -0.7415.18, 95% CI = -1.2423.85 to -0.256.40) in favor of the experimental group patients, based on the analysis results of four included studies. However, the I2-value of 0% showed that the heterogeneity was low.

CONCLUSION

SSNHL during pregnancy is a notably rare condition with an unknown cause. However, hormonal fluctuations, particularly increased levels of estrogen and progesterone during pregnancy, have been frequently implicated as potential triggers for SSNHL.

Large vestibular schwannomas presenting in the late state of pregnancy: a case report and literature review

Vestibular schwannomas in pregnancy have rarely been reported, and there is a lack of in-depth discussion on the experience of management of massive acoustic neuromas in pregnancy. Herein, we present a pregnant woman with a giant vestibular schwannoma and obstructive hydrocephalus who presented at 30 weeks of gestation. She was initially misdiagnosed as having a pregnancy-related reaction of headache, dizziness, and vomiting that had occurred 2 months earlier. After observation at home, her symptoms progressed at 30 weeks of gestation, and imaging findings revealed a brain tumor in the CPA region with secondary cerebella tonsil herniation and obstructive hydrocephalus, and she was transferred to our center for treatment. Consequently, we relieved her hydrocephalus with a ventriculoperitoneal shunt (V-P shunt) and used corticosteroids to simulate fetal maturation. After 10 days, her mental condition deteriorated, and her right limb muscle strength gradually decreased until grade 0 (MMT Grading). Finally, under a joint consultation with the Department of Neurosurgery, Obstetrics, and Anesthesiology, she underwent a cesarean section under general anesthesia and first-stage tumor removal at 31 weeks of gestation. Upon discharge, the previously observed neurological deficits, which were reversible and had manifested during her gestational period, had been successfully resolved, and the fetus had been conserved. The neuroimaging confirmed the complete tumor removal, while the neuropathologic examination revealed a vestibular schwannoma. Therefore, we recommend early diagnosis and treatment for these patients, especially people with headaches, vomiting, and sudden hearing loss during pregnancy. Herein, we concluded that our cases provide a valuable experience in the latest acceptable time frame for the operation to prevent irreversible neurological impairment and premature delivery in late pregnancy.

Sex-Linked Biology and Gender-Related Research Is Essential to Advancing Hearing Health

There is robust evidence that sex (biological) and gender (behavioral/social) differences influence hearing loss risk and outcomes. These differences are noted for animals and humans-in the occurrence of hearing loss, hearing loss progression, and response to interventions. Nevertheless, many studies have not reported or disaggregated data by sex or gender. This article describes the influence of sex-linked biology (specifically sex-linked hormones) and gender on hearing and hearing interventions, including the role of sex-linked biology and gender in modifying the association between risk factors and hearing loss, and the effects of hearing loss on quality of life and functioning. Most prevalence studies indicate that hearing loss begins earlier and is more common and severe among men than women. Intrinsic sex-linked biological differences in the auditory system may account, in part, for the predominance of hearing loss in males. Sex- and gender-related differences in the effects of noise exposure or cardiovascular disease on the auditory system may help explain some of these differences in the prevalence of hearing loss. Further still, differences in hearing aid use and uptake, and the effects of hearing loss on health may also vary by sex and gender. Recognizing that sex-linked biology and gender are key determinants of hearing health, the present review concludes by emphasizing the importance of a well-developed research platform that proactively measures and assesses sex- and gender-related differences in hearing, including in understudied populations. Such research focus is necessary to advance the field of hearing science and benefit all members of society.

Sudden sensorineural hearing loss during pregnancy: etiology, treatment, and outcome

OBJECTIVE

To analyze the etiologies, treatments, and outcomes of sensorineural hearing loss (SSNHL) during pregnancy.

STUDY DESIGN

Retrospective chart review of 25 pregnant patients treated for SSNHL between January 2012 and September 2019. Forty-nine age matched non-pregnant women with severe and profound hearing loss diagnosed with SSNHL during the same period served as controls. Data were recorded on age, symptoms, onset of hearing loss, audiometric results, treatments, and outcomes.

RESULTS

The mean age was 29.6 years (range 23-38 years). Intratympanic steroids (ITS) were administered in 15 (60.0%) pregnant women with SSNHL. Three women were treated with postauricular steroids only, while another woman was treated with intravenous ginkgo leaf extract and dipyridamole. The remaining six women received no medications. More than half (8/15, 53.3%) of pregnant women with SSNHL receiving ITS experienced hearing improvement. Pregnant women with profound hearing loss who received no medication had no hearing improvement. Most pregnant women with SSNHL (12/15, 80.0%) had higher fibrinogen levels than controls (mean values 3.77±0.71 g/L and 2.54±0.48 g/L, respectively).

CONCLUSION

Fibrinogen could be a risk factor for SSNHL during pregnancy. ITS may benefit pregnant women with severe and profound SSNHL.

Permanent hearing loss and tinnitus following epidural analgesia complicated by accidental dural puncture

We report a case of permanent high-frequency hearing loss and tinnitus in a 38-year-old woman following an unrecognised dural puncture during epidural placement. The patient reported subjective unilateral hearing loss and tinnitus, along with a post-dural puncture headache, four hours post-delivery. The patient's headache resolved following two epidural blood patches, however, hearing loss and tinnitus persisted longer than two years. Long-term auditory symptoms following epidural analgesia in labour are very unusual findings.

Understanding hormone and hormone therapies' impact on the auditory system

Hormones such as estrogen, progesterone, and aldosterone all demonstrate vital roles in sustaining auditory function through either the maintenance of cochlear neurons, up/down regulation of critical molecules (i.e., IGF-1, BDNF, etc.), or generation of the endocochlear potential. With disease and/or age, hormone expression begins to decline drastically, which ultimately affects cochlear structures and the integrity of cochlear cells. The following review explores the latest findings as well as realistic outcomes for hormone therapy treatment in the auditory system. This information could serve as a potential guide for patients considering hormone therapy as a medicinal choice to alleviate the signs of onset of presbycusis-age-related hearing loss. Additional scientific investigations could also be carried out to further enhance recent findings.

Can Pregnancy Lead to Changes in Hearing Threshold?

PURPOSE

This study explores the changes in hearing thresholds in pregnancy.

MATERIALS AND METHODS

A prospective hospital-based observational study was performed with a total of 69 patients in the age-group of 18 to 40 years. Patients underwent hearing assessment twice during the study period. Conventional pure tone audiometry and impedance audiometry were performed, first during the antepartum period (28-32 weeks of gestational age) and second time during the postpartum period (6 weeks postpartum).

RESULTS

Significant difference was seen between the average of air conduction threshold values at speech frequencies when antepartum values were compared with postpartum values.

CONCLUSION

The alterations in hearing sensitivity in pregnant females which improved during the postpartum period can be attributed to pregnancy.

Clinical management and progress in sudden sensorineural hearing loss during pregnancy

Sudden sensorineural hearing loss (SSNHL) is a relatively rare, but distressing, disease in pregnant women. Little is known about the causes, clinical manifestations, treatments, and prognosis of SSNHL. Some hypotheses have been proposed to explain the pathophysiological mechanism of SSNHL, but most of them have not been identified. This article reviews the existing literature to present a summary of this clinical problem. Most patients suffer from SSNHL in the second or third trimester, and show moderate to profound hearing loss. The interval between the initial treatment and onset of hearing loss is less than 10 days in most patients. Some patients with SSNHL show tinnitus, vertigo, or dizziness, and fullness of the ear. Although some patients have a tendency for self-cure, treatment with intravenous dextran 40 combined with intratympanic corticosteroids is probably a safe and effective therapeutic strategy for pregnant patients with SSNHL. Further clinical research is necessary to identify the best therapeutic strategy for these patients.

Pregnancy Does Not Increase the Risk of Sudden Sensorineural Hearing Loss: A National Cohort Study

OBJECTIVES/HYPOTHESIS

Pregnancy-induced systemic physiological changes appear to be associated with reversible hearing changes in pregnant/postpartum women. However, most studies are case reports due to the rare occurrence of sudden sensorineural hearing loss (SSNHL) during pregnancy. We aimed to evaluate the risk of SSNHL during the pregnancy and postpartum periods.

STUDY DESIGN

A longitudinal case-control study using a nationwide population cohort.

METHODS

Using the Korean National Health Insurance Review and Assessment Service, we collected data from 63,331 pregnant/postpartum participants who were matched 1:2 by age, income, region of residence, and medical history with 126,662 control participants. We included participants who had International Classification of Diseases, 10th Revision (ICD-10) codes indicating delivery (O80-O84). For SSNHL (ICD-10 code H91.2), we included only those participants who underwent audiometry and were treated with steroids. The incidence of SSNHL was measured for the periods corresponding to pregnancy (conception through delivery) up to 1 year postpartum in the pregnant participants.

RESULTS

During the pregnancy period, the SSNHL rate was not higher (19.5 per 100,000) compared with the control group (60.7 per 100,000). The adjusted odds ratio of SSNHL during pregnancy was 0.32 (95% confidence interval: 0.16-0.65, P = .002). The SSNHL rate during the postpartum period (37.9 per 100,000) was similar to that of the control group (36.3 per 100,000). The adjusted odds ratio of SSNHL during the postpartum period was 1.04 (95% confidence interval: 0.64-1.71, P = .867). The risk of SSNHL in the patients during the pregnancy/postpartum period was not higher than that in controls, regardless of age and specific subperiod.

CONCLUSIONS

The pregnant and postpartum women were not at higher risk of SSNHL.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:E237-E242, 2020.

Sudden sensorineural hearing loss during pregnancy: clinical characteristics, management and outcome

BACKGROUND

Sudden sensorineural hearing loss (SSNHL) may occur during pregnancy with a rare prevalence, and little is known about it.

AIMS

To retrospectively analyze cases of SSNHL during pregnancy and investigate their clinical characteristics, management and outcome.

MATERIAL AND METHODS

Records of 30 SSNHL patients during pregnancy were reviewed, including age, localization, duration from onset to treatment, gestation period, accompanying symptoms, initial hearing threshold, final hearing threshold, audiogram, treatment and outcome.

RESULTS

Twenty-four patients (80.0%) suffered SSNHL in the second trimester or the last trimester with a high rate of tinnitus (70.0%). The initial hearing threshold was 63.4 ± 25.1 dB, and most audiograms were flat and profound. The overall recovery rate was 60.0%, including complete recovery (33.3%) and partial recovery (26.7%). Further, 16 patients received adjuvant intratympanic steroid showed a better audiologic outcome (improvement 27.1 ± 16.4 vs. 15.7 ± 12.0 dB, p = .042) than those who had not.

CONCLUSIONS AND SIGNIFICANCE

SSNHL during pregnancy often occurred in the second trimester or the last trimester with a severe hearing loss, the most audiogram configurations are flat and profound. Dextran-40 is a safe and beneficial therapy for SSNHL patients during pregnancy and adjuvant intratympanic steroid increase the probability of hearing recovery.

Estrogenic modulation of auditory processing: a vertebrate comparison

Sex-steroid hormones are well-known regulators of vocal motor behavior in several organisms. A large body of evidence now indicates that these same hormones modulate processing at multiple levels of the ascending auditory pathway. The goal of this review is to provide a comparative analysis of the role of estrogens in vertebrate auditory function. Four major conclusions can be drawn from the literature: First, estrogens may influence the development of the mammalian auditory system. Second, estrogenic signaling protects the mammalian auditory system from noise- and age-related damage. Third, estrogens optimize auditory processing during periods of reproductive readiness in multiple vertebrate lineages. Finally, brain-derived estrogens can act locally to enhance auditory response properties in at least one avian species. This comparative examination may lead to a better appreciation of the role of estrogens in the processing of natural vocalizations and mayprovide useful insights toward alleviating auditory dysfunctions emanating from hormonal imbalances.