Introduction: Pre-eclampsia is marked by increase in blood pressure and a raised level of protein in the urine and women will often also have swelling in the feet, legs, and hands. This condition usually appears during the second half of pregnancy; the pathological changes that happen during pre-eclampsia will be consequence of vasoconstriction of blood vessels, endothelial malfunction and ischemia. Hypertension and hemo-vascular disorder that accompany the disease can influence any organ including inner ear. The aim of the present study is to study the effect of pre-eclampsia on the inner ear by using Distortion product otoacoustic emission (DPOAEs).
Patients and Methods: Our study is a prospective one that done at Otorhinolaryngology, Obstetric and Audiology clinics at Minia University Hospital, from March 2011 to December 2012. It composed of patient's group that suffer from pre-eclampsia with mean age 25.3 years old and control group representing healthy pregnant women with mean age 25.4 years old. The entire study sample was subjected to audiological evaluation (Distortion product otoacoustic emission, Immitancemetry, Stapedial reflex and pure tone audiometry). Systemic and Obstetric evaluation was done to both groups.
Results: Immitancemetry, stapedial reflex and pure tone audiometry were normal in both groups, while Distortion product otoacoustic emission was statistically significant lower amplitudes in nearly one third of the patient's groups at all F2 frequencies except at 6250 Hz, while none of the ears of the control group had abnormal DPOAEs.
Conclusion: Pre-eclampsia can influence cochlear function and be a risk factor for sensory neural hearing loss in affected women.
Pre-eclampsia, Hearing, Cochlea
Preeclampsia is defined as increase in blood
pressure and proteinuria after 20 weeks of
pregnancy in a woman who not suffer previously
from hypertension, if left untreated; preeclampsia
can lead to serious and fatal complications for both
the mother and her baby . Preeclampsia is a serious
condition that puts pregnant women at risk for
failure of multiple organs including inner ear, due to
vascular events and systemic toxemia .
Preeclampsia is a common disorder that is a
consequence of vasospasm, endothelial dysfunction
and ischaemia , Preeclampsia, which affects
circulation with possible immunologic pathogenesis,
can induce damage to the cochlea and result in
sensory neural hearing loss . The aim of our study is to evaluate cochlear changes by using Otoacoustic
emission in pre-eclamptic women.
Subjects and Methods
The study was approved by The Research Ethics
Committee of the faculty of Medicine, Minia
University. A written consent was signed by all
women that enrolled in the study. The current
study is a prospective study that done on 16 female
patients, that suffer from pre-eclampsia (the study
group); and 18 healthy pregnant mothers represent
the control group. The mean age of study group
was 25.3 years and that of control group was 25.4
The study was done at Otorhinolaryngology,
Obstetric and Audiology clinics at Minia University
Hospital, from March 2011 to December 2013.
All patients and control groups subject to:
1. Detailed medical history
2. Obstetric examination
3. Laboratory investigation in the form of
(complete blood count, blood glucose, renal
function tests, liver function tests and urine
4. Full Otorhinolaryngological examination
5. Medical examination including measurement
of blood pressure.
The patient is diagnosed as having pre-eclampsia
if she passed 20 weeks gestation; blood pressure
is 140/90 mmHg or higher-documented on two
measures, at least six hours apart but no more than
seven days apart and there is protein in urine after
α. Patients with chronic suppurative otitis media
(unilateral or bilateral)
β. Patients with previous ear surgery
χ. Patients with known history of hearing loss
δ. Patients with otosclerosis
ε. Patients with previous medical diseases
like Diabetes, Hypertension, autoimmune
1. Immitancemetry using Zodiac 401 middel ear
analyser to measure middle ear preassure and
stapedial muscle reflex at frequencies 500,
1000, 2000, and 4000 Hz.
2. Pure tone audiometry using Amplaid 309
audiometer for assessment of hearing
sensitivity. Air conduction (AC) threshold was
obtained for the frequency range 250-8000
Hz at single octave intervals through using
TDH 49 ear phone, while bone conduction
(BC) threshold was obtained for the frequency
range 500-4000 Hz at single octave intervals
using B71 bone vibrator.
3. Distortion product otoacoustic emission
(DPOAE) to test the cochlear function. DPOAE
was recorded using the Intelligent Hearing® system with Smart OAE 4.5 software. Two
tones were used; L1=65 dB SPL and L2=55 dB
SPL, while f2/f1 was 1.22. Both the amplitude
of response of the distortion product (DP) at 2
f1-f2 and background noise (Ns) were obtained
at 9 points corresponding to f2 frequencies of
553, 783, 1105, 1560, 2211, 3125, 4416, 6250
and 8837 Hz. These measurements were used
to build DP-gram by displaying the DP against
the F2 frequency. The SNR was measured
(SNR=DP-Ns) at each of these 9 points. DPOAE
normal and thereby reflecting
normal cochlear function if the SNR was equal
to or greater than 3 dB SPL on at least 70% of
the tested frequencies.
Our data was collected and analyzed statistically
by using student t-tests
Our results revealed statistically significant lower
DPOAE amplitudes in the study groups at all F2
frequencies except at 6250 Hz, while none of the ears
of the control groups had abnormal DPOAEs (Tables
1 and 2). Show Mean and SD of DPOAE amplitudes
in dB SPL of the right and left ear-consequently for
both study and control groups; in addition to t and p
values of the student t test.
|F2 Frequency (kHz)
Table 1: Mean and SD of DPOAE amplitudes in dB SPL of the right ear for both study and control groups; in
addition to the t and p values of the student t test.
|F2 Frequency (kHz)
Table 2: Shows mean and SD of DPOAE amplitudes in dB SPL of the left ear for both study and control groups;
in addition to the t and p values of the student t test.
The results of the present study revealed that
36.4% of patients of the study group had abnormal
DPOAEs (i.e., the DPOAEs was greater than 3 dB SPL
in less than 70% of the tested frequencies)
Our results pointed out that there is no statistical
difference between patient and control groups in
Immitancemetry and stapedial muscle reflex, as they
were normal in both groups. Our results showed also,
that pure tone audiometry at examined frequencies
were normal in both groups
Otoacoustic emissions especially the distortion product type (Distortion product otoacoustic
emissions; DPOAEs) is a sensitive test for cochlear
function. It has excellent test retest reliability and
it can detect sub-clinical cochlear abnormality
before these abnormalities manifest clinically in
the conventional audiogram. Therefore it has been
used to monitor cochlear function in patients taking
ototoxic medications as gentamycin and subject
under noise exposure. Compared to the transient
otoacoustic emissions (TOAEs), DPOAEs is more
frequency specific and test wider frequency range
than TEOAEs .
Arterial hypertension may affect hearing by
different ways. High pressure in the cochlear
microcirculation may cause haemorrhage in the inner
ear, which may cause progressive or sudden sensory
neural hearing loss. As blood viscosity is increased
due to pre-eclampsia the capillary blood flow and
oxygen saturation in the cochlea are reduced which
causes tissue hypoxia that can cause hearing deficits and hearing loss in hypertensive patients. Moreover,
increase in arterial blood pressure may cause ionic
changes in cell potentials of the hair cells of the
cochlea, thus causing hearing loss [6-9].
The pathogenesis of preeclampsia is complicated
and not fully understood. It may be associated with
multiorgan failures of the mother, coagulopathy,
vasospasm, ischemia and microthrombi in peripheral
circulation that my lead to maternal and foetal [4,10].
Bakhshaee et al. stated that damage to the
cochlear hair cells during preeclampsia was possible.
Theyevaluated hearing in 37 preeclamptic patients
and 38 healthy women with TEOAE and reveal
significant differences between the two groups, as
13.5% of pre-eclamptic women had abnormality
in TEOAE. These findings pointed out the possible
effect of preeclampsia on the cochlea at least
temporarily . Our results showed that 36.4% of the
ears of pre-eclamptic women had abnormal DPOAEs which agree with Bakhshaee et al. and as we use of
DPOAEs which is more sensitive than TEOAE, explain
the higher results that we have.
Altunta et al. pointed out that, there was no
significant difference between hypertensive and
healthy pregnant women in terms of hearing
assessment, but damage to the cochlear hair cells
consequent to hypertension during pregnancy
is possible. The results of his study suggested
that ischaemia of the inner ear that caused by
microthrombus and vasospasm in hypertensive
patients during pregnancy does not result in hearing
impairment in the postpartum period6. Our results
disagree with Altunta et al. as there is hearing
impairment detected by DPOAEs in 36.4% of preeclmptic
Ozdemir et al. found statistically significant
differences between per-eclamptic and healthy
women in pure-tone audiometric results. However,
these results were irrelevant clinically as all puretone
thresholds were lower than 20 dB (normal
hearing abilities). The differences between brainstem auditory-evoked potentials were not statistically
significant . Our results disagree with Ozdmir et al.
as there is no statistical difference between both
groups in pure tone audiometery and our data
showed significant difference between patient's
group and control group regarding DPOAEs.
Baylan et al. OAE-right, and OAE-left differed
significantly between pre-eclamptic patient and
control groups also bone conduction at 500 Hz
significantly differ between both groups in pure
tone audiometry . Our results agree with Baylan
in OAE results but differ in pure tone audiometery
as our results pointed out that no statistical
difference between both groups regarding pure tone
Our results pointed out that pre-eclampsia can
influence the cochlea and in turn it may be a risk
factor for sensory neural hearing loss in pregnant
women, this may be temporarily. We recommend
doing this study on wide scale of patients and
following them for a while in postpartum.
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- Baylan MY, Kuyumcuoglu U, Kale A, Celik Y, Topcu I (2010) Is preeclampsia a new risk factor for cochlear damage and hearing loss? OtolNeurotol 31: 1180-1183.