The incidence of tinnitus in pregnancy is higher than in the general population. It is the most common ear complaint reported during pregnancy affecting over 1 in 3 women compared to just 1 in 10 women of the same age who are not pregnant. Furthermore, 2 out of 3 women who have tinnitus before pregnancy report an increase in their tinnitus during pregnancy, especially during the second and towards the third trimester (months 4 to 6). For those who first experience tinnitus during pregnancy it is often present throughout the pregnancy and resolves or reduces after delivery.

The nerve cells present in the cochlea (a structure in the inner ear) convert vibrations caused by sound waves into electrical impulses which travel via the auditory nerve into the brain. Physical changes which occur during pregnancy which interfere with this sensitive process can account for the new or increased perception of tinnitus. For example, changes which occur during pregnancy include a normal increase in circulating blood volume and an increase in blood pressure. The inner ear is surrounded by several major blood vessels and this increase in pressure is transmitted directly to fluid inside the cochlea. This fluid regulates electrical impulses from the inner ear to the brain and so changes in pressure in the cochlea may lead to alterations in these electrical impulses and the perception of tinnitus.

Another candidate mechanism is the natural retention of salts and water that occur during pregnancy. This can cause localised swelling, which if affecting the tissues surrounding the cochlea may alter electrical impulses between the ear and brain and affect tinnitus.

Natural changes in circulating levels of the hormones oestrogen and progesterone may also be a factor. These chemical changes can alter the nerve cell activity of the inner ear and causing or increasing tinnitus.

Pregnancy is a time of both physical and emotional demands on every woman. The first time occurrence of tinnitus during pregnancy, or the increase of existing tinnitus can be alarming. It is clearly a real concern for the many pregnant women who seek reassurance on internet blog sites or by contacting the British Tinnitus Association. Given a likely connection to raised blood pressure, tinnitus may be an early warning sign of gestational hypertension or pre-eclampsia (a serious complication of pregnancy).

As such a pregnant woman who experiences tinnitus for the first time or notices an increase in her existing tinnitus should report it to her midwife or GP. Prompt reporting is recommended to rule out potential complications of pregnancy and to get appropriate management and monitoring. Furthermore, if tinnitus during pregnancy is accompanied by a new hearing loss then a referral to ENT for appropriate investigations will be necessary.

In cases where any other symptoms are ruled out, informed reassurance by a healthcare professional is all that is required. This should consist of providing information about tinnitus, reassurance that there are many natural explanations for the experience of tinnitus during pregnancy, and the promotion of general well-being, rest, and relaxation.

References


Sennaroglu G and Belgin E Audiological findings in pregnancy. Journal of Laryngology and Otology, 2001: 115(8):617–621.
Kumar R, Hayhurst KL and Robson AK Ear, nose and throat manifestations during pregnancy. Otolaryngology - head and neck surgery, 2011: 145(2): 188-198.