Exposure To Smoke During Pregnancy and Infancy May Cause Hearing Loss

By June 29, 2018

A Japanese study suggests that an unborn baby exposed to tobacco smoke in the womb and in infancy could double the loss of developing hearing loss.

Researchers examined data on 50,734 children born between 2004 and 2010 in Kobe City, Japan. Overall, about 4 per cent of these kids were exposed to smoking during pregnancy or infancy, and roughly 1 per cent had tobacco exposure during both periods.

Hearing tests done when kids were 3 years old found that 4.6 percent of the children had hearing loss.

They were 68 percent more likely to have hearing loss if they were exposed to tobacco during pregnancy, and 30 percent more likely if they inhaled second-hand smoke during infancy, the study found.

When kids had smoke exposure during both periods, they were 2.4 times more likely than unexposed kids to have hearing loss.

When pregnant women smoke, it may harm fetal brain development and lead to auditory cognitive dysfunction, Pezzoli added. Tobacco smoke may also damage sensory receptors in the ear that relay messages to the brain based on sound vibration.

Globally, about 68 million people have a hearing impairment that is thought to have originated in childhood, Koji Kawakami of Kyoto University in Japan and colleagues note in Paediatric and Perinatal Epidemiology. Kawakami didn't respond to requests for comment.

Researchers assessed children's hearing using what's known as a whisper test. For these tests, mothers stood behind their kids to prevent lip reading, then whispered a word while kids' had one ear covered.

While this test is simple and considered an accurate way to assess hearing in adults and older children, there's some concern about how reliable the results may be in young kids.

To protect children against hearing problems caused by cigarette smoke, it's important for women to quit before they become pregnant or as soon as they discover they're pregnant, said Huanhuan Hu, a researcher at the National Center for Global Health and Medicine in Japan who wasn't involved in the study.

Reference:
Reuters Health, "Smoke Exposure During Pregnancy and Infancy Ties To Hearing Loss", Channel NewsAsia, 29 June 2018

Last modified on Friday, 29 June 2018 20:56