Smoking During Pregnancy May Cause Hearing Problems in Kids

We’ve long known that cigarette smoking during pregnancy is harmful to both mum and baby. Besides miscarriage and stillbirth, smoking while pregnant may increase a woman’s risk of having a premature or underweight baby.

Now results from a mouse study show that nicotine exposure before and after birth could cause hearing problems in kids. According to the study, women who smoke during pregnancy and after delivering the baby may raise risk of their children for damaging the hearing.

The study from Freie Universitat Berlin in Germany demonstrates that children who get exposed to nicotine before birth or during breastfeeding are more likely to suffer from hearing issues, due to abnormal development in the brain’s auditory region.

Maternal smoking during pregnancy has previously been linked to deteriorate the brain development of a fetus. The auditory brainstem is a segment of the brain which is important for analysing sound patterns. Children with impaired impaired auditory brainstem function are prone to experience problems with language development and learning difficulties.

For the current study, the German scientists fed pregnant mice with drinking water laced with nicotine at levels equivalent to those taken up by heavy human smokers. They exposed offspring of the mice to nicotine before birth and via the mother mice’s milk. The offspring were exposed to nicotine until they were three weeks old, which is almost equivalent to primary school children. The scientists then tested the firing properties and signalling abilities of neurons in brains of offspring after they were born.

When compared with unexposed offspring, in exposed offspring, neurons sensitive to input from the inner ear were less good at transmitting signals to other brain cells.

Lead researcher Professor Ursula Koch, from the Free University of Berlin said: “We do not know how many other parts of the auditory system are affected by nicotine exposure. More research is needed about the cumulative effect of nicotine exposure and the molecular mechanisms of how nicotine influences the development of neurons in the auditory brain stem.

“If mothers smoke during pregnancy and their children show learning difficulties at school, they should be tested for auditory processing deficits.”

Not only cigarettes smoking during pregnancy, even the use of electronic cigarettes, popularly known as e-cigarettes, or nicotine replacement therapy during pregnancy has been linked to an increased risk of premature delivery, decreased birth weight of child, and an increased rate of sudden infant death.

The findings were published in The Journal of Physiology